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Sample records for scaffolded mind higher

  1. Protein scaffolds and higher-order complexes in synthetic biology

    NARCIS (Netherlands)

    den Hamer, A.; Rosier, B.J.H.M.; Brunsveld, L.; de Greef, T.F.A.; Ryadnov, M.; Brunsveld, L.; Suga, H.

    2017-01-01

    Interactions between proteins control molecular functions such as signalling or metabolic activity. Assembly of proteins via scaffold proteins or in higher-order complexes is a key regulatory mechanism. Understanding and functionally applying this concept requires the construction, study, and

  2. Encouraging Higher-Order Thinking in General Chemistry by Scaffolding Student Learning Using Marzano's Taxonomy

    Science.gov (United States)

    Toledo, Santiago; Dubas, Justin M.

    2016-01-01

    An emphasis on higher-order thinking within the curriculum has been a subject of interest in the chemical and STEM literature due to its ability to promote meaningful, transferable learning in students. The systematic use of learning taxonomies could be a practical way to scaffold student learning in order to achieve this goal. This work proposes…

  3. Mindfulness

    DEFF Research Database (Denmark)

    Chiesa, Alberto; Serretti, Alessandro; Jakobsen, Janus Christian

    2013-01-01

    The beneficial clinical effects of mindfulness practices are receiving increasing support from empirical studies. However, the functional neural mechanisms underlying these benefits have not been thoroughly investigated. Some authors suggest that mindfulness should be described as a 'top......-down' emotion regulation strategy, while others suggest that mindfulness should be described as a 'bottom-up' emotion regulation strategy. Current discrepancies might derive from the many different descriptions and applications of mindfulness. The present review aims to discuss current descriptions...... of mindfulness and the relationship existing between mindfulness practice and most commonly investigated emotion regulation strategies. Recent results from functional neuro-imaging studies investigating mindfulness training within the context of emotion regulation are presented. We suggest that mindfulness...

  4. Mindfulness

    DEFF Research Database (Denmark)

    Agger Nielsen, Jeppe; Nielsen, Charlotte Agger

    2013-01-01

    Mindfulness har de senere år budt sig til som effektiv hjælp til selvhjælp for fortravlede ledere og professionelle. Men er meditationsøvelser og forsøg på at finde indre ”zen”-ro overhovedet lederens anstrengelser værd? Denne artikel diskuterer effekterne af mindfulness og giver ordet til såvel...

  5. The advantage of higher-order theory of mind in the game of limited bidding

    NARCIS (Netherlands)

    De Weerd, H.; Verheij, B.; van Eijck, J.; Verbrugge, L. C.

    2011-01-01

    Higher-order theory of mind is the ability to recursively model mental states of other agents. It is known that adults in general can reason adequately at the second order (covering attributions like "Alice knows that Bob knows that she wrote a novel under pseudonym"), but there are cognitive limits

  6. Mindfulness in higher education: awareness and attention in university students increase during and after participation in a mindfulness curriculum course

    NARCIS (Netherlands)

    de Bruin, E.I.; Meppelink, R.; Bögels, S.M.

    2015-01-01

    This study assessed the effects of a mindfulness course in the curriculum of international students (n = 104) from 16 different countries at the University of Amsterdam. The curriculum consisted of seven weekly lectures, as well as studying scientific articles on mindfulness research and gaining

  7. Modelling in Action. Scaffolding High School Students to Higher Levels of Autonomy: The School's Elevator and the Inverse Problem

    Science.gov (United States)

    Marmolejo Rivas, Eugenia

    2017-01-01

    In this paper, we focus our discussion on the strategy we follow to scaffold high school students to successfully build models of a real-life system. Our aim is for students to gradually achieve a higher level of autonomy and to use and further develop their mathematical knowledge. We present work students did when we asked them to build a model…

  8. Enhancing students' higher order thinking skills through computer-based scaffolding in problem-based learning

    Science.gov (United States)

    Kim, Nam Ju

    This multiple paper dissertation addressed several issues in Problem-based learning (PBL) through conceptual analysis, meta-analysis, and empirical research. PBL is characterized by ill-structured tasks, self-directed learning process, and a combination of individual and cooperative learning activities. Students who lack content knowledge and problem-solving skills may struggle to address associated tasks that are beyond their current ability levels in PBL. This dissertation addressed a) scaffolding characteristics (i.e., scaffolding types, delivery method, customization) and their effects on students' perception of optimal challenge in PBL, b) the possibility of virtual learning environments for PBL, and c) the importance of information literacy for successful PBL learning. Specifically, this dissertation demonstrated the effectiveness of scaffolding customization (i.e., fading, adding, and fading/adding) to enhance students' self-directed learning in PBL. Moreover, the effectiveness of scaffolding was greatest when scaffolding customization is self-selected than based on fixed-time interval and their performance. This suggests that it might be important for students to take responsibility for their learning in PBL and individualized and just-in-time scaffolding can be one of the solutions to address K-12 students' difficulties in improving problem-solving skills and adjusting to PBL.

  9. Higher mind-brain development in successful leaders: testing a unified theory of performance.

    Science.gov (United States)

    Harung, Harald S; Travis, Frederick

    2012-05-01

    This study explored mind-brain characteristics of successful leaders as reflected in scores on the Brain Integration Scale, Gibbs's Socio-moral Reasoning questionnaire, and an inventory of peak experiences. These variables, which in previous studies distinguished world-class athletes and professional classical musicians from average-performing controls, were recorded in 20 Norwegian top-level managers and in 20 low-level managers-matched for age, gender, education, and type of organization (private or public). Top-level managers were characterized by higher Brain Integration Scale scores, higher levels of moral reasoning, and more frequent peak experiences. These multilevel measures could be useful tools in selection and recruiting of potential managers and in assessing leadership education and development programs. Future longitudinal research could further investigate the relationship between leadership success and these and other multilevel variables.

  10. Higher-order theory of mind in negotiations under incomplete information

    NARCIS (Netherlands)

    de Weerd, Hermanes; Verbrugge, Rineke; Verheij, Bart; Boella, Guido; Elkind, Edith; Savarimuthu, Bastin Tony Roy; Dignum, Frank; Purvis, Martin

    2013-01-01

    Theory of mind refers to the ability to reason explicitly about unobservable mental content such as beliefs, desires, and intentions of others. People are known to make use of theory of mind, and even reason about what other people believe about their beliefs. Although it is unknown why such a

  11. Incorporating Mind Maps into Teaching and Learning in Higher Education: My Experience as an International University Lecturer

    Science.gov (United States)

    Guo, Xin

    2014-01-01

    This article seeks to share the author's teaching experience as an international lecturer in a UK university and in particular promote the use of Mind Maps (MM) in teaching and learning in higher education. The audience to whom the article could be beneficial is university lecturers who either are in their early teaching career or face challenges…

  12. Exploring personality traits, mindfulness and sense of coherence of women working in higher education

    Directory of Open Access Journals (Sweden)

    Claude-Hélène Mayer

    2016-07-01

    Full Text Available Orientation: Previous research shows that personality traits (PT, mindfulness (MI and sense of coherence (SOC are connected to psychological well-being and of importance to Human Resource Management (HRM. Purpose: The purpose of this article was to determine the relationship between PT, MI and SOC of women working in South African Higher Education Institutions (HEIs. Motivation for study: The study explores the relationships of PT, MI and SOC in women in HEIs to contribute to a deeper understanding of these relationships within the HRM context, particularly with regard to training and development in HEIs. Research design, approach and method: A cross-sectional, survey-based research design was used to address the research objective. Both snowball and convenience sampling were utilised to obtain the sample (n = 125. The sample was derived from the Higher Education Resource Services network. The Life Orientation Questionnaire, Freiburger MI Inventory and Big Five PT Questionnaire were utilised and showed acceptable levels of reliability. Exploratory factor analysis with either a direct oblimin or varimax rotation was used to investigate the factor structure of the questionnaires (λ < 1 were used, because one of the questionnaires had not been used in the South African context before. Descriptive statistics, factor analysis, Spearman/ Pearson correlations, canonical correlations and multiple regressions were used to determine the relationship between the variables. Main findings: The results showed a significant relationship between the components PT, MI and SOC. It appears that PT plays a significant role in influencing MI and SOC. Practical/managerial implications: Managers and human resource practitioners need to recognise how PT, MI and SOC interrelate and need to become aware of the impact of these positive psychological constructs on women in HEIs. Contribution: These findings contribute new knowledge that can be used to create healthy HEIs

  13. The Serenity of the Meditating Mind: A Cross-Cultural Psychometric Study on a Two-Factor Higher Order Structure of Mindfulness, Its Effects, and Mechanisms Related to Mental Health among Experienced Meditators

    Science.gov (United States)

    Tran, Ulrich S.; Cebolla, Ausiàs; Glück, Tobias M.; Soler, Joaquim; Garcia-Campayo, Javier; von Moy, Theresa

    2014-01-01

    Objective To investigate the psychometric and structural properties of the Five Facets Mindfulness Questionnaire (FFMQ) among meditators, to develop a short form, and to examine associations of mindfulness with mental health and the mechanisms of mindfulness. Methods Two independent samples were used, a German (n = 891) and a Spanish (n = 393) meditator sample, practicing various meditation styles. Structural and psychometric properties of the FFMQ were investigated with multigroup confirmatory factor analysis and exploratory structural equation modeling. Associations with mental health and mechanisms of mindfulness were examined with path analysis. Results The derived short form broadly matched a previous item selection in samples of non-meditators. Self-regulated Attention and Orientation to Experience governed the facets of mindfulness on a higher-order level. Higher-order factors of mindfulness and meditation experience were negatively associated with symptoms of depression and anxiety, and perceived stress. Decentering and nonattachment were the most salient mechanisms of mindfulness. Aspects of emotion regulation, bodily awareness, and nonattachment explained the effects of mindfulness on depression and anxiety. Conclusions A two-component conceptualization for the FFMQ, and for the study of mindfulness as a psychological construct, is recommended for future research. Mechanisms of mindfulness need to be examined in intervention studies. PMID:25330072

  14. The serenity of the meditating mind: a cross-cultural psychometric study on a two-factor higher order structure of mindfulness, its effects, and mechanisms related to mental health among experienced meditators.

    Directory of Open Access Journals (Sweden)

    Ulrich S Tran

    Full Text Available OBJECTIVE: To investigate the psychometric and structural properties of the Five Facets Mindfulness Questionnaire (FFMQ among meditators, to develop a short form, and to examine associations of mindfulness with mental health and the mechanisms of mindfulness. METHODS: Two independent samples were used, a German (n = 891 and a Spanish (n = 393 meditator sample, practicing various meditation styles. Structural and psychometric properties of the FFMQ were investigated with multigroup confirmatory factor analysis and exploratory structural equation modeling. Associations with mental health and mechanisms of mindfulness were examined with path analysis. RESULTS: The derived short form broadly matched a previous item selection in samples of non-meditators. Self-regulated Attention and Orientation to Experience governed the facets of mindfulness on a higher-order level. Higher-order factors of mindfulness and meditation experience were negatively associated with symptoms of depression and anxiety, and perceived stress. Decentering and nonattachment were the most salient mechanisms of mindfulness. Aspects of emotion regulation, bodily awareness, and nonattachment explained the effects of mindfulness on depression and anxiety. CONCLUSIONS: A two-component conceptualization for the FFMQ, and for the study of mindfulness as a psychological construct, is recommended for future research. Mechanisms of mindfulness need to be examined in intervention studies.

  15. Agent-based models for higher-order theory of mind

    NARCIS (Netherlands)

    de Weerd, Harmen; Verbrugge, Rineke; Verheij, Bart; Kamiński, Bogumił; Koloch, Grzegorz

    2014-01-01

    Agent-based models are a powerful tool for explaining the emergence of social phenomena in a society. In such models, individual agents typically have little cognitive ability. In this paper, we model agents with the cognitive ability to make use of theory of mind. People use this ability to reason

  16. Semiotic scaffolding

    DEFF Research Database (Denmark)

    Hoffmeyer, Jesper

    2015-01-01

    Life processes at all levels (from the genetic to the behavioral) are coordinated by semiotic interactions between cells, tissues, membranes, organs, or individuals and tuned through evolution to stabilize important functions. A stabilizing dynamics based on a system of semiotic scaffoldings impl...... semiotic scaffolding is not, of course, exclusive for phylogenetic and ontogenetic development, it is also an important dynamical element in cultural evolution.......Life processes at all levels (from the genetic to the behavioral) are coordinated by semiotic interactions between cells, tissues, membranes, organs, or individuals and tuned through evolution to stabilize important functions. A stabilizing dynamics based on a system of semiotic scaffoldings...... (the representamen) and the effect. Semiotic interaction patterns therefore provide fast and versatile mechanisms for adaptations, mechanisms that depend on communication and “learning” rather than on genetic preformation. Seen as a stabilizing agency supporting the emergence of higher-order structure...

  17. Theory of mind in remitted bipolar disorder: Younger patients struggle in tasks of higher ecological validity.

    Science.gov (United States)

    Feyerabend, Julia; Lüttke, Stefan; Grosse-Wentrup, Fabienne; Wolter, Sibylla; Hautzinger, Martin; Wolkenstein, Larissa

    2018-04-15

    To date, research concerning Theory of Mind (ToM) in remitted bipolar disorder (rBD) has yielded inconclusive results. This may be a result of methodological shortcomings and the failure to consider relevant third variables. Furthermore, studies using ecologically valid stimuli are rare. This study examines ToM in rBD patients, using ecologically valid stimuli. Additionally, the effects of sad mood induction (MI) as well as of age and gender are considered. The sample comprises N = 44 rBD patients (rBDPs) and N = 40 healthy controls (HCs). ToM decoding is assessed using the Cambridge Mindreading Face-Voice-Battery (CAM) and ToM reasoning using the Movie for the Assessment of Social Cognition (MASC). Both tasks were divided into two parts to conduct one part with and one without MI. While across the whole sample there was no evidence that rBDPs and HCs differed in ToM decoding or reasoning, in the younger subsample (age < 45) rBDPs performed worse than HCs in ToM decoding. While MI negatively influenced reasoning in both groups, gender had no effect. Most patients in this study had a high level of social functioning, limiting the generalizability of the results. As important social steps have to be undertaken before middle-age, the decoding deficits in younger rBDPs might be of particular importance not only for social functioning but also for the course of illness. Furthermore, this age-related deficit may explain the inconclusive findings that have been reported so far. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Mapping Trends and Framing Issues in Higher Music Education: Changing Minds/Changing Practices

    Science.gov (United States)

    Minors, Helen Julia; Burnard, Pamela; Wiffen, Charles; Shihabi, Zaina; van der Walt, J. Simon

    2017-01-01

    This article presents five case studies from within music in higher education programmes that collectively explore key questions concerning how we look at the challenges and trends, and the need for change to react to the recent higher education (HE) climate, through reference to teaching musicians the skills, knowledge and diverse career…

  19. Mind the gap: gender disparities still to be addressed in UK Higher Education geography

    OpenAIRE

    Maddrell, Avril; Strauss, Kendra; Thomas, Nicola J.; Wyse, Stephanie

    2016-01-01

    This paper evidences persistent gender inequalities in UK higher education (HE) geography departments. The two key sources of data used are: Higher Education Statistics Agency (HESA) data for staff and students, which affords a longitudinal response to earlier surveys by McDowell and McDowell and Peake of women in UK university geography departments, and a qualitative survey of the UK HE geography community undertaken in 2010 that sought more roundly to capture respondent reflections on their...

  20. The Relationship between Spiritual Intelligence, Mindfulness, and Transformational Leadership among Public Higher Education Leaders

    Science.gov (United States)

    Gieseke, Amy R.

    2014-01-01

    Since the mid-1990s, researchers have grown increasingly interested in the effect of spirituality on a person's ability to lead others. The spiritual leadership literature has expanded to include the role of spirituality in particular leadership settings, such as higher education, and within particular leadership types, particularly…

  1. Mindfulness as an Intervention for Recalling Information from a Lecture as a Measure of Academic Performance in Higher Education: A Randomized Experiment

    Science.gov (United States)

    Bennett, Rebecca Iranzo; Egan, Helen; Cook, Amy; Mantzios, Michail

    2018-01-01

    Higher education students experience heightened levels of stress and anxiety, and report experiencing negative thoughts and emotions, which influence information retention and recall. In a randomized experiment, we assigned participants to either a mindfulness meditation or an audiobook listening condition, and recorded the information recalled…

  2. The emotional fundamentals of personality and the higher affective polarities of mind. Comment on "Personality from a cognitive-biological perspective" by Y. Neuman

    Science.gov (United States)

    Panksepp, Jaak; Davis, Ken

    2014-12-01

    In brain-based personality theory, two things seem certain: i) the evolved functional organization of our subcortical affective mind, and ii) the diverse potentials for developmental programming of our high cognitive minds (i.e., our initially empty - tabula rasa like - neocortical spaces are largely developmentally programed to manifest higher mental abilities). In considering these two global aspects of brain-mind functions, we can be confident that primal subcortical functions (e.g., the capacity for raw emotions/affects, evident in all vertebrate species) evolved. Indeed, ancient creatures such as lamprey eels, with whom we shared ancestry 560 million years ago, still posses most neural systems that are homologous to those that constitute our own primal affective capacities [1]. Considering that primal emotional affects arise from such systems, there appears to be some remarkable continuity in our primal mental origins. The neural foundations of human emotional feelings, long neglected by academic psychology (for lack of empirical accessibility), may contain the rudimentary neuro-affective substrates of personality [2].

  3. Parallel fabrication of macroporous scaffolds.

    Science.gov (United States)

    Dobos, Andrew; Grandhi, Taraka Sai Pavan; Godeshala, Sudhakar; Meldrum, Deirdre R; Rege, Kaushal

    2018-07-01

    Scaffolds generated from naturally occurring and synthetic polymers have been investigated in several applications because of their biocompatibility and tunable chemo-mechanical properties. Existing methods for generation of 3D polymeric scaffolds typically cannot be parallelized, suffer from low throughputs, and do not allow for quick and easy removal of the fragile structures that are formed. Current molds used in hydrogel and scaffold fabrication using solvent casting and porogen leaching are often single-use and do not facilitate 3D scaffold formation in parallel. Here, we describe a simple device and related approaches for the parallel fabrication of macroporous scaffolds. This approach was employed for the generation of macroporous and non-macroporous materials in parallel, in higher throughput and allowed for easy retrieval of these 3D scaffolds once formed. In addition, macroporous scaffolds with interconnected as well as non-interconnected pores were generated, and the versatility of this approach was employed for the generation of 3D scaffolds from diverse materials including an aminoglycoside-derived cationic hydrogel ("Amikagel"), poly(lactic-co-glycolic acid) or PLGA, and collagen. Macroporous scaffolds generated using the device were investigated for plasmid DNA binding and cell loading, indicating the use of this approach for developing materials for different applications in biotechnology. Our results demonstrate that the device-based approach is a simple technology for generating scaffolds in parallel, which can enhance the toolbox of current fabrication techniques. © 2018 Wiley Periodicals, Inc.

  4. Mind the Gap: An Initial Analysis of the Transition of a Second Level Curriculum Reform to Higher Education

    Science.gov (United States)

    Prendergast, Mark; Faulkner, Fiona; Breen, Cormac; Carr, Michael

    2017-01-01

    This article details an initial analysis of the transition of a second level curriculum reform to higher education in Ireland. The reform entitled 'Project Maths' involved changes to what second level students learn in mathematics, how they learn it, and how they are assessed. Changes were rolled out nationally on a phased basis in September 2010.…

  5. Minding the Gap? Young People's Accounts of Taking a Gap Year as a Form of Identity Work in Higher Education

    Science.gov (United States)

    King, Andrew

    2011-01-01

    A Gap Year is a break in an educational career, principally taken between leaving school and beginning university. Previous research on the Gap Year has suggested it is a form of social class positioning or forum for undertaking transitions in identity during young adulthood. This paper extends this research into the context of higher education…

  6. Mindfulness Interventions.

    Science.gov (United States)

    Creswell, J David

    2017-01-03

    Mindfulness interventions aim to foster greater attention to and awareness of present moment experience. There has been a dramatic increase in randomized controlled trials (RCTs) of mindfulness interventions over the past two decades. This article evaluates the growing evidence of mindfulness intervention RCTs by reviewing and discussing (a) the effects of mindfulness interventions on health, cognitive, affective, and interpersonal outcomes; (b) evidence-based applications of mindfulness interventions to new settings and populations (e.g., the workplace, military, schools); (c) psychological and neurobiological mechanisms of mindfulness interventions; (d) mindfulness intervention dosing considerations; and (e) potential risks of mindfulness interventions. Methodologically rigorous RCTs have demonstrated that mindfulness interventions improve outcomes in multiple domains (e.g., chronic pain, depression relapse, addiction). Discussion focuses on opportunities and challenges for mindfulness intervention research and on community applications.

  7. Scaffolded biology.

    Science.gov (United States)

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology.

  8. Developmental Scaffolding

    DEFF Research Database (Denmark)

    Giorgi, Franco; Bruni, Luis Emilio

    2015-01-01

    . Within the developmental hierarchy, each module yields an inter-level relationship that makes it possible for the scaffolding to mediate the production of selectable variations. Awide range of genetic, cellular and morphological mechanisms allows the scaffolding to integrate these modular variations...... to the complexity of sign recognition proper of a cellular community. In this semiotic perspective, the apparent goal directness of any developmental strategy should no longer be accounted for by a predetermined genetic program, but by the gradual definition of the relationships selected amongst the ones...

  9. When Traits Match States: Examining the Associations between Self-Report Trait and State Mindfulness following a State Mindfulness Induction.

    Science.gov (United States)

    Bravo, Adrian J; Pearson, Matthew R; Wilson, Adam D; Witkiewitz, Katie

    2018-02-01

    Previous research has found inconsistent relationships between trait mindfulness and state mindfulness. To extend previous research, we sought to examine the unique associations between self-report trait mindfulness and state mindfulness by levels of meditation experience (meditation-naïve vs. meditation-experienced) and by mindfulness induction (experimentally induced mindful state vs. control group). We recruited 299 college students (93 with previous mindfulness meditation experience) to participate in an experiment that involved the assessment of five facets of trait mindfulness (among other constructs), followed by a mindfulness induction (vs. control), followed by the assessment of state mindfulness of body and mind. Correlational analyses revealed limited associations between trait mindfulness facets and facets of state mindfulness, and demonstrated that a brief mindfulness exercise focused on bodily sensations and the breath elicited higher state mindfulness of body but not state mindfulness of mind. We found significant interactions such that individuals with previous meditation experience and higher scores on the observing facet of trait mindfulness had the highest levels of state mindfulness of body and mind. Among individuals with meditation experience, the strengths of the associations between observing trait mindfulness and the state mindfulness facets increased with frequency of meditation practice. Some other interactions ran counter to expectations. Overall, the relatively weak associations between trait and state mindfulness demonstrates the need to improve our operationalizations of mindfulness, advance our understanding of how to best cultivate mindfulness, and reappraise the ways in which mindfulness can manifest as a state and as a trait.

  10. Mindful innovation

    DEFF Research Database (Denmark)

    Olsen, Poul Bitsch

    2008-01-01

    Mindful innovation is an approach to innovation that pays attention to people's experience in an organization rather than to formal organization or social role.......Mindful innovation is an approach to innovation that pays attention to people's experience in an organization rather than to formal organization or social role....

  11. The Mindful Self: A Mindfulness-Enlightened Self-view

    Directory of Open Access Journals (Sweden)

    Qianguo Xiao

    2017-10-01

    Full Text Available This paper analyzes studies of mindfulness and the self, with the aim of deepening our understanding of the potential benefits of mindfulness and meditation for mental health and well-being. Our review of empirical research reveals that positive changes in attitudes toward the self and others as a result of mindfulness-enabled practices can play an important role in modulating many mental and physical health problems. Accordingly, we introduce a new concept—the “mindful self”—and compare it with related psychological constructs to describe the positive changes in self-attitude associated with mindfulness meditation practices or interventions. The mindful self is conceptualized as a mindfulness-enlightened self-view and attitude developed by internalizing and integrating the essence of Buddhist psychology into one’s self-system. We further posit that the mindful self will be an important intermediary between mindfulness intervention and mental health problems, and an important moderator in promoting well-being. More generally, we suggest that the mindful self may also be an applicable concept with which to describe and predict the higher level of self-development of those who grow up in the culture of Buddhism or regularly engage in meditation over a long period of time.

  12. Writing in Mind

    Directory of Open Access Journals (Sweden)

    Georg Theiner

    2013-09-01

    Full Text Available According to the “extended mind” thesis, a significant portion of human cog-nition does not occur solely inside the head, but literally extends beyond the brain into the body and the world around us (Clark & Chalmers 1998; Clark 2003, 2008; Wilson 1995, 2004; Rowlands 1999, 2010; Menary 2007, 2012; Sutton 2010; Theiner 2011. One way to understand this thesis is that as human beings, we are particularly adept at creating and recruiting environmental props and scaffolds (media, tools, artifacts, symbol systems for the purpose of solving problems that would otherwise lie beyond our cognitive reach. We manipulate, scaffold, and re-design our environments in ways that transform the nature of difficult tasks that would baffle our unaided biological brains (e.g., math, logic, sequential problem-solving into simpler types of problems that we are naturally much better equipped to solve. A central tenet of the “extended mind” thesis, then, is that “much of what matters for human-level intelligence is hidden not in the brain, nor in the technology, but in the complex and iterated interactions and collaborations between the two” (Clark 2001: 154. Over the past fifteen years or so, the “extended mind” thesis has become a hot ticket in the philosophy of mind. As with all great ideas, the thesis was hardly conceived ex nihilo, but builds on, and re-articulates many earlier strands of thought. Unfortunately, many of those cognate strands have become marginalized in contemporary philosophy of mind and psychology, and do not receive the amount of attention they deserve. Part of what we hope to accomplish with this special issue is to reverse this trend, and to rekindle the dialogue between the “extended mind” thesis and its historical predecessors.

  13. Peer Scaffolding Behaviors Emerging in Revising a Written Task: A Microgenetic Analysis

    Science.gov (United States)

    Ranjbar, Naser; Ghonsooly, Behzad

    2017-01-01

    Vygotsky's writings on Sociocultural Theory (SCT) of mind, his concept of Zone of Proximal Development (ZPD) and its related metaphor, scaffolding, serve as the theoretical basis for the study of peer collaboration. This paper aimed at examining the effects of peer-scaffolding on EFL writing ability and finding out how revising techniques are…

  14. The Role of Mindfulness to Improve Leadership in Multicultural Context

    OpenAIRE

    Dhevy Puswiartika; Zahrotur Rusyda Hinduan; Marina Sulastiana; Diana Harding

    2017-01-01

    Mindfulness is present moment awareness with an observing and nonjudging stance. To be mindful means to be fully in the here and now from moment to moment. Mindfulness appears to have broadly positive impacts on human functioning. This review explored the current state of studies regarding mindfulness as a potential psychological construct to improve leadership in multicultural context. Mindfulness associated with higher relationship quality because a mindful leader is better able to be fully...

  15. Calming the Monkey Mind

    Science.gov (United States)

    Eliuk, Kendra; Chorney, David

    2017-01-01

    Many of today's students are experiencing higher levels of stress and anxiety in school. The need for competitive grades, the desire to be seen as perfect in a digital society, and parental pressures are only some of the reasons that students are experiencing more stress. This increased stress has lead to an overworked mind for many youth, dubbed…

  16. Scaffold diversification enhances effectiveness of a superlibrary of hyperthermophilic proteins.

    Science.gov (United States)

    Hussain, Mahmud; Gera, Nimish; Hill, Andrew B; Rao, Balaji M

    2013-01-18

    The use of binding proteins from non-immunoglobulin scaffolds has become increasingly common in biotechnology and medicine. Typically, binders are isolated from a combinatorial library generated by mutating a single scaffold protein. In contrast, here we generated a "superlibrary" or "library-of-libraries" of 4 × 10(8) protein variants by mutagenesis of seven different hyperthermophilic proteins; six of the seven proteins have not been used as scaffolds prior to this study. Binding proteins for five different model targets were successfully isolated from this library. Binders obtained were derived from five out of the seven scaffolds. Strikingly, binders from this modestly sized superlibrary have affinities comparable or higher than those obtained from a library with 1000-fold higher sequence diversity but derived from a single stable scaffold. Thus scaffold diversification, i.e., randomization of multiple different scaffolds, is a powerful alternate strategy for combinatorial library construction.

  17. Efter mindfulness

    DEFF Research Database (Denmark)

    Stjernholm, Ole; Ehrensvärd, Martin Gustaf

    Tematiserer nogle af de udfordringer, der møder dig, som regelmæssigt praktiserer mindfulness og kommer med bud på, hvad bevidsthedens vaner og mønstre betyder for dybden af stilhed - og hvordan man kan arbejde med den viden.......Tematiserer nogle af de udfordringer, der møder dig, som regelmæssigt praktiserer mindfulness og kommer med bud på, hvad bevidsthedens vaner og mønstre betyder for dybden af stilhed - og hvordan man kan arbejde med den viden....

  18. Mindfulness meditation

    DEFF Research Database (Denmark)

    Grünenberg, Kristina; Walker, Hanne Kjærgaard; Knudsen, Jakob Skov

    2009-01-01

    Meditation er ikke et nyt fænomen i det danske samfund. Det er den fokus som meditationsformen Mindfulness Based Stress Reduction (MBSR) har været genstand for i de senere år imidlertid. Inden for en sundhedssociologisk ramme undersøges nogle af grundene til, at netop MBSR er blevet populær både i...... en analyse af empirien, i hvilken forfatterne bl.a. argumenterer for, at opfattelsen af virkninger tilskrevet mindfulness meditation må ses i relation til to diskurser, som fremanalyseres og benævnes henholdsvis autenticitets- og e ektiviseringsdiskurserne. Disse diskurser udgør i artiklen...

  19. Does mindfulness matter? Everyday mindfulness, mindful eating and self-reported serving size of energy dense foods among a sample of South Australian adults.

    Science.gov (United States)

    Beshara, Monica; Hutchinson, Amanda D; Wilson, Carlene

    2013-08-01

    Serving size is a modifiable determinant of energy consumption, and an important factor to address in the prevention and treatment of obesity. The present study tested an hypothesised negative association between individuals' everyday mindfulness and self-reported serving size of energy dense foods. The mediating role of mindful eating was also explored. A community sample of 171 South Australian adults completed self-report measures of everyday mindfulness and mindful eating. The dependent measure was participants' self-reported average serving size of energy dense foods consumed in the preceding week. Participants who reported higher levels of everyday mindfulness were more mindful eaters (r=0.41, pMindful eating fully mediated the negative association between everyday mindfulness and serving size. The domains of mindful eating most relevant to serving size included emotional and disinhibited eating. Results suggest that mindful eating may have a greater influence on serving size than daily mindfulness. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Mindful movement and skilled attention

    Science.gov (United States)

    Clark, Dav; Schumann, Frank; Mostofsky, Stewart H.

    2015-01-01

    Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel “mind-body connection” has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited) behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage “higher-order” inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer’s spectrum of mindful learning that spans from “mindlessness” to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais’ suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other

  1. Mindful Movement and Skilled Attention

    Directory of Open Access Journals (Sweden)

    Dav eClark

    2015-06-01

    Full Text Available Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel mind-body connection has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage higher-order inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer’s spectrum of mindful learning that spans from mindlessness to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais’ suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other

  2. State Mindfulness During Meditation Predicts Enhanced Cognitive Reappraisal

    Science.gov (United States)

    Hanley, Adam; Farb, Norman A.; Froeliger, Brett E.

    2013-01-01

    Putatively, mindfulness meditation involves generation of a state of “nonappraisal”, yet, little is known about how mindfulness may influence appraisal processes. We investigated whether the state and practice of mindfulness could enhance cognitive reappraisal. Participants (N = 44; M age = 24.44, SD = 4.00, range 19 – 38, 82.2% female) were randomized to either 1) mindfulness, 2) suppression, or 3) mind-wandering induction training conditions. Cognitive reappraisal was assessed with the Emotion Regulation Questionnaire (ERQ) prior to experimental induction, and state mindfulness was assessed immediately following induction using the Toronto Mindfulness Scale (TMS). Participants practiced their assigned strategy for one week and then were reassessed with the ERQ reappraisal subscale. Participants receiving mindfulness training reported significantly higher levels of state mindfulness than participants in the thought suppression and mind wandering conditions. Although brief mindfulness training did not lead to significantly greater increases in reappraisal than the other two conditions, state mindfulness during mindfulness meditation was prospectively associated with increases in reappraisal. Path analysis revealed that the indirect effect between mindfulness training and reappraisal was significant through state mindfulness. Degree of state mindfulness achieved during the act of mindfulness meditation significantly predicted increases in reappraisal over time, suggesting that mindfulness may promote emotion regulation by enhancing cognitive reappraisal. PMID:26085851

  3. Mindfulness for group facilitation

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Krohn, Simon

    2014-01-01

    In this paper, we argue that mindfulness techniques can be used for enhancing the outcome of group performance. The word mindfulness has different connotations in the academic literature. Broadly speaking there is ‘mindfulness without meditation’ or ‘Western’ mindfulness which involves active...... thinking and ‘Eastern’ mindfulness which refers to an open, accepting state of mind, as intended with Buddhist-inspired techniques such as meditation. In this paper, we are interested in the latter type of mindfulness and demonstrate how Eastern mindfulness techniques can be used as a tool for facilitation....... A brief introduction to the physiology and philosophy of Eastern mindfulness constitutes the basis for the arguments of the effect of mindfulness techniques. The use of mindfulness techniques for group facilitation is novel as it changes the focus from individuals’ mindfulness practice...

  4. The Mind of Consciousness

    Indian Academy of Sciences (India)

    Human mind, often considered synonymous ... between the monoists who believe that mind ... mental process in its own right, as widespread ... real challenge for experimental scientists is to devise ... several books like "The Minds of Robots",.

  5. Oculometric variations during mind wandering

    Directory of Open Access Journals (Sweden)

    Romain eGrandchamp

    2014-02-01

    Full Text Available A significant body of literature supports the contention that pupil size varies depending on cognitive load, affective state, and level of drowsiness. Here we assessed whether oculometric measures such as gaze position, blink frequency and pupil size were correlated with the occurrence and time course of self-reported mind-wandering episodes. We recorded the pupil size of two subjects engaged in a monotonous breath counting task while keeping their eyes on a fixation cross. Each subject performed ten 20-minute sessions, for total duration of about 4 hours. This task is conducive to producing mind-wandering episodes. Subjects were instructed to report spontaneous mind-wandering episodes by pressing a button when they lost count of their breath. After each button press, subjects filled in a short questionnaire describing the characteristics of their mind-wandering episode. We observed larger pupil size during the breath-focusing period compared to the mind-wandering period (p< 0.01 for both subjects. Our findings contradict previous research showing a higher baseline pupil size during mind wandering episodes in visual tasks. We discuss possible explanations for this discrepancy. We also analyzed nine other oculometric measures including blink rate, blink duration and gaze position. We built a support vector machine classifier and showed that mean pupil size was the most reliable predictors of mind wandering in both subjects. The classification accuracy of mind wandering data segments versus breath-focusing data segments was 81% for the first subject and 77% for the second subject. Additionally, we analyzed oculometric measures in light of the phenomenological data collected in the questionnaires. We showed that how well subjects remembered their thoughts while mind wandering was positively correlated with pupil size (subject 1, p< 0.001; subject 2, p< 0.05. Feelings of well being were also positively correlated with pupil size (subject 1, p< 0

  6. Magnetic responsive hydroxyapatite composite scaffolds construction for bone defect reparation.

    Science.gov (United States)

    Zeng, Xiao Bo; Hu, Hao; Xie, Li Qin; Lan, Fang; Jiang, Wen; Wu, Yao; Gu, Zhong Wei

    2012-01-01

    In recent years, interest in magnetic biomimetic scaffolds for tissue engineering has increased considerably. A type of magnetic scaffold composed of magnetic nanoparticles (MNPs) and hydroxyapatite (HA) for bone repair has been developed by our research group. In this study, to investigate the influence of the MNP content (in the scaffolds) on the cell behaviors and the interactions between the magnetic scaffold and the exterior magnetic field, a series of MNP-HA magnetic scaffolds with different MNP contents (from 0.2% to 2%) were fabricated by immersing HA scaffold into MNP colloid. ROS 17/2.8 and MC3T3-E1 cells were cultured on the scaffolds in vitro, with and without an exterior magnetic field, respectively. The cell adhesion, proliferation and differentiation were evaluated via scanning electron microscopy; confocal laser scanning microscopy; and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase, and bone gla protein activity tests. The results demonstrated the positive influence of the magnetic scaffolds on cell adhesion, proliferation, and differentiation. Further, a higher amount of MNPs on the magnetic scaffolds led to more significant stimulation. The magnetic scaffold can respond to the exterior magnetic field and engender some synergistic effect to intensify the stimulating effect of a magnetic field to the proliferation and differentiation of cells.

  7. Computational physics of the mind

    Science.gov (United States)

    Duch, Włodzisław

    1996-08-01

    In the XIX century and earlier physicists such as Newton, Mayer, Hooke, Helmholtz and Mach were actively engaged in the research on psychophysics, trying to relate psychological sensations to intensities of physical stimuli. Computational physics allows to simulate complex neural processes giving a chance to answer not only the original psychophysical questions but also to create models of the mind. In this paper several approaches relevant to modeling of the mind are outlined. Since direct modeling of the brain functions is rather limited due to the complexity of such models a number of approximations is introduced. The path from the brain, or computational neurosciences, to the mind, or cognitive sciences, is sketched, with emphasis on higher cognitive functions such as memory and consciousness. No fundamental problems in understanding of the mind seem to arise. From a computational point of view realistic models require massively parallel architectures.

  8. Microfibrous silver-coated polymeric scaffolds with tunable mechanical properties

    KAUST Repository

    Kalakonda, Parvathalu.; Aldhahri, Musab A.; Abdel-wahab, Mohamed Shaaban; Tamayol, Ali; Moghaddam, K. Mollazadeh; Ben Rached, Fathia; Pain, Arnab; Khademhosseini, Ali; Memic, Adnan; Chaieb, Saharoui

    2017-01-01

    Electrospun scaffolds of poly(glycerol sebacate)/poly(ε-caprolactone) (PGS/PCL) have been used for engineered tissues due to their desirable thermal and mechanical properties as well as their tunable degradability. In this paper, we fabricated micro-fibrous scaffolds from a composite of PGS/PCL using a standard electrospinning method and coated them with silver (Ag). The low temperature coating method prevented substrate melting and the Ag coating decreases the pore size and increases the diameter of fibers which resulted in enhanced thermal and mechanical properties. We further compared the mechanical properties of the composite fibrous scaffolds with different thicknesses of Ag coated scaffolds. The composite fibrous scaffold with a 275 nm Ag coating showed higher tensile modulus (E) and ultimate tensile strength (UTS) without any post-processing treatment. Lastly, potential controlled release of the Ag coating from the composite fibrous scaffolds could present interesting biomedical applications.

  9. Microfibrous silver-coated polymeric scaffolds with tunable mechanical properties

    KAUST Repository

    Kalakonda, Parvathalu.

    2017-07-07

    Electrospun scaffolds of poly(glycerol sebacate)/poly(ε-caprolactone) (PGS/PCL) have been used for engineered tissues due to their desirable thermal and mechanical properties as well as their tunable degradability. In this paper, we fabricated micro-fibrous scaffolds from a composite of PGS/PCL using a standard electrospinning method and coated them with silver (Ag). The low temperature coating method prevented substrate melting and the Ag coating decreases the pore size and increases the diameter of fibers which resulted in enhanced thermal and mechanical properties. We further compared the mechanical properties of the composite fibrous scaffolds with different thicknesses of Ag coated scaffolds. The composite fibrous scaffold with a 275 nm Ag coating showed higher tensile modulus (E) and ultimate tensile strength (UTS) without any post-processing treatment. Lastly, potential controlled release of the Ag coating from the composite fibrous scaffolds could present interesting biomedical applications.

  10. Schizotypy and mindfulness: Magical thinking without suspiciousness characterizes mindfulness meditators

    Directory of Open Access Journals (Sweden)

    Elena Antonova

    2016-09-01

    Full Text Available Despite growing evidence for demonstrated efficacy of mindfulness in various disorders, there is a continuous concern about the relationship between mindfulness practice and psychosis. As schizotypy is part of the psychosis spectrum, we examined the relationship between long-term mindfulness practice and schizotypy in two independent studies. Study 1 included 24 experienced mindfulness practitioners (19 males from the Buddhist tradition (meditators and 24 meditation-naïve individuals (all males. Study 2 consisted of 28 meditators and 28 meditation-naïve individuals (all males. All participants completed the Schizotypal Personality Questionnaire (Raine, 1991, a self-report scale containing 9 subscales (ideas of reference, excessive social anxiety, magical thinking, unusual perceptual experiences, odd/eccentric behavior, no close friends, odd speech, constricted affect, suspiciousness. Participants of study 2 also completed the Five-Facet Mindfulness Questionnaire which assesses observing (Observe, describing (Describe, acting with awareness (Awareness, non-judging of (Non-judgment and non-reactivity to inner experience (Non-reactivity facets of trait mindfulness. In both studies, meditators scored significantly lower on suspiciousness and higher on magical thinking compared to meditation-naïve individuals and showed a trend towards lower scores on excessive social anxiety. Excessive social anxiety correlated negatively with Awareness and Non-judgment; and suspiciousness with Awareness, Non-judgment and Non-reactivity facets across both groups. The two groups did not differ in their total schizotypy score. We conclude that mindfulness practice is not associated with an overall increase in schizotypal traits. Instead, the pattern suggests that mindfulness meditation, particularly with an emphasis on the Awareness, Non-judgment and Non-reactivity aspects, may help to reduce suspiciousness and excessive social anxiety.

  11. Oxygen Plasma Treatment on 3D-Printed Chitosan/Gelatin/Hydroxyapatite Scaffolds for Bone Tissue Engineering.

    Science.gov (United States)

    Lee, Chang-Min; Yang, Seong-Won; Jung, Sang-Chul; Kim, Byung-Hoon

    2017-04-01

    The 3D hydroxyapatite/gelatin/chitosan composite scaffolds were fabricated by 3D printing technique. The scaffolds were treated by oxygen plasma to improve the bioactivity and its surface characterization and in vitro cell culture were investigated. The scaffolds exhibited the good porosity and interconnectivity of pores. After oxygen plasma etching, roughness and wettability on the scaffolds surface are increased. Plasma treated scaffolds showed higher proliferation than that of untreated scaffolds. Oxygen plasma treatment could be used as potential tool to enhance the biocompatibility on the 3D composite scaffolds.

  12. Composite porous scaffold of PEG/PLA support improved bone matrix deposition in vitro compared to PLA-only scaffolds.

    Science.gov (United States)

    Bhaskar, Birru; Owen, Robert; Bahmaee, Hossein; Wally, Zena; Sreenivasa Rao, Parcha; Reilly, Gwendolen C

    2018-05-01

    Controllable pore size and architecture are essential properties for tissue-engineering scaffolds to support cell ingrowth colonization. To investigate the effect of polyethylene glycol (PEG) addition on porosity and bone-cell behavior, porous polylactic acid (PLA)-PEG scaffolds were developed with varied weight ratios of PLA-PEG (100/0, 90/10, 75/25) using solvent casting and porogen leaching. Sugar 200-300 µm in size was used as a porogen. To assess scaffold suitability for bone tissue engineering, MLO-A5 murine osteoblast cells were cultured and cell metabolic activity, alkaline phosphatase (ALP) activity and bone-matrix production determined using (alizarin red S staining for calcium and direct red 80 staining for collagen). It was found that metabolic activity was significantly higher over time on scaffolds containing PEG, ALP activity and mineralized matrix production were also significantly higher on scaffolds containing 25% PEG. Porous architecture and cell distribution and penetration into the scaffold were analyzed using SEM and confocal microscopy, revealing that inclusion of PEG increased pore interconnectivity and therefore cell ingrowth in comparison to pure PLA scaffolds. The results of this study confirmed that PLA-PEG porous scaffolds support mineralizing osteoblasts better than pure PLA scaffolds, indicating they have a high potential for use in bone tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1334-1340, 2018. © 2018 Wiley Periodicals, Inc.

  13. Exact approaches for scaffolding

    OpenAIRE

    Weller, Mathias; Chateau, Annie; Giroudeau, Rodolphe

    2015-01-01

    This paper presents new structural and algorithmic results around the scaffolding problem, which occurs prominently in next generation sequencing. The problem can be formalized as an optimization problem on a special graph, the "scaffold graph". We prove that the problem is polynomial if this graph is a tree by providing a dynamic programming algorithm for this case. This algorithm serves as a basis to deduce an exact algorithm for general graphs using a tree decomposition of the input. We ex...

  14. Novel biodegradable porous scaffold applied to skin regeneration.

    Science.gov (United States)

    Wang, Hui-Min; Chou, Yi-Ting; Wen, Zhi-Hong; Wang, Chau-Zen; Wang, Zhao-Ren; Chen, Chun-Hong; Ho, Mei-Ling

    2013-01-01

    Skin wound healing is an important lifesaving issue for massive lesions. A novel porous scaffold with collagen, hyaluronic acid and gelatin was developed for skin wound repair. The swelling ratio of this developed scaffold was assayed by water absorption capacity and showed a value of over 20 g water/g dried scaffold. The scaffold was then degraded in time- and dose-dependent manners by three enzymes: lysozyme, hyaluronidase and collagenase I. The average pore diameter of the scaffold was 132.5±8.4 µm measured from SEM images. With human skin cells growing for 7 days, the SEM images showed surface fractures on the scaffold due to enzymatic digestion, indicating the biodegradable properties of this scaffold. To simulate skin distribution, the human epidermal keratinocytes, melanocytes and dermal fibroblasts were seeded on the porous scaffold and the cross-section immunofluorescent staining demonstrated normal human skin layer distributions. The collagen amount was also quantified after skin cells seeding and presented an amount 50% higher than those seeded on culture wells. The in vivo histological results showed that the scaffold ameliorated wound healing, including decreasing neutrophil infiltrates and thickening newly generated skin compared to the group without treatments.

  15. Novel biodegradable porous scaffold applied to skin regeneration.

    Directory of Open Access Journals (Sweden)

    Hui-Min Wang

    Full Text Available Skin wound healing is an important lifesaving issue for massive lesions. A novel porous scaffold with collagen, hyaluronic acid and gelatin was developed for skin wound repair. The swelling ratio of this developed scaffold was assayed by water absorption capacity and showed a value of over 20 g water/g dried scaffold. The scaffold was then degraded in time- and dose-dependent manners by three enzymes: lysozyme, hyaluronidase and collagenase I. The average pore diameter of the scaffold was 132.5±8.4 µm measured from SEM images. With human skin cells growing for 7 days, the SEM images showed surface fractures on the scaffold due to enzymatic digestion, indicating the biodegradable properties of this scaffold. To simulate skin distribution, the human epidermal keratinocytes, melanocytes and dermal fibroblasts were seeded on the porous scaffold and the cross-section immunofluorescent staining demonstrated normal human skin layer distributions. The collagen amount was also quantified after skin cells seeding and presented an amount 50% higher than those seeded on culture wells. The in vivo histological results showed that the scaffold ameliorated wound healing, including decreasing neutrophil infiltrates and thickening newly generated skin compared to the group without treatments.

  16. Injectable porous nano-hydroxyapatite/chitosan/tripolyphosphate scaffolds with improved compressive strength for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Uswatta, Suren P.; Okeke, Israel U. [Department of Bioengineering, The University of Toledo, Toledo, OH 43614 (United States); Jayasuriya, Ambalangodage C., E-mail: a.jayasuriya@utoledo.edu [Department of Bioengineering, The University of Toledo, Toledo, OH 43614 (United States); Department of Orthopaedic Surgery, The University of Toledo, Toledo, OH 43614 (United States)

    2016-12-01

    studies. 2% nHA/chitosan scaffolds showed higher osteoblast attachment than 0% nHA/chitosan scaffolds. - Highlights: • Injectable porous scaffolds prepared from chitosan and nano-hydroxyapatite. • Scaffolds are fabricated using non-toxic coacervation and lyophilization techniques. • 2% nHA/chitosan scaffolds exhibited the highest ultimate compressive strength. • Scaffolds' compressive strength can be increased by simple soaking and drying. • Scaffolds showed very good osteoblast adhesion and proliferation.

  17. Injectable porous nano-hydroxyapatite/chitosan/tripolyphosphate scaffolds with improved compressive strength for bone regeneration

    International Nuclear Information System (INIS)

    Uswatta, Suren P.; Okeke, Israel U.; Jayasuriya, Ambalangodage C.

    2016-01-01

    studies. 2% nHA/chitosan scaffolds showed higher osteoblast attachment than 0% nHA/chitosan scaffolds. - Highlights: • Injectable porous scaffolds prepared from chitosan and nano-hydroxyapatite. • Scaffolds are fabricated using non-toxic coacervation and lyophilization techniques. • 2% nHA/chitosan scaffolds exhibited the highest ultimate compressive strength. • Scaffolds' compressive strength can be increased by simple soaking and drying. • Scaffolds showed very good osteoblast adhesion and proliferation.

  18. PCL-coated hydroxyapatite scaffold derived from cuttlefish bone: In vitro cell culture studies

    International Nuclear Information System (INIS)

    Milovac, Dajana; Gamboa-Martínez, Tatiana C.; Ivankovic, Marica; Gallego Ferrer, Gloria; Ivankovic, Hrvoje

    2014-01-01

    In the present study, we examined the potential of using highly porous poly(ε-caprolactone) (PCL)-coated hydroxyapatite (HAp) scaffold derived from cuttlefish bone for bone tissue engineering applications. The cell culture studies were performed in vitro with preosteoblastic MC3T3-E1 cells in static culture conditions. Comparisons were made with uncoated HAp scaffold. The attachment and spreading of preosteoblasts on scaffolds were observed by Live/Dead staining Kit. The cells grown on the HAp/PCL composite scaffold exhibited greater spreading than cells grown on the HAp scaffold. DNA quantification and scanning electron microscopy (SEM) confirmed a good proliferation of cells on the scaffolds. DNA content on the HAp/PCL scaffold was significantly higher compared to porous HAp scaffolds. The amount of collagen synthesis was determined using a hydroxyproline assay. The osteoblastic differentiation of the cells was evaluated by determining alkaline phosphatase (ALP) activity and collagen type I secretion. Furthermore, cell spreading and cell proliferation within scaffolds were observed using a fluorescence microscope. - Highlights: • Hydroxyapatite/poly(ε-caprolactone) scaffold with interconnected pores was prepared • Cytotoxicity test showed that the scaffold was not cytotoxic towards MC3T3-E1 cells • The scaffold supported the attachment, proliferation and differentiation of cells • A 3D cell colonization was confirmed using the fluorescence microscopy • The scaffold might be a promising candidate for bone tissue engineering

  19. Electrophysiological Correlates of Reading the Single- and Interactive-Mind

    Science.gov (United States)

    Wang, Yi-Wen; Zheng, Yu-Wei; Lin, Chong-De; Wu, Jie; Shen, De-Li

    2011-01-01

    Understanding minds is the cognitive basis of successful social interaction. In everyday life, human mental activity often happens at the moment of social interaction among two or multiple persons instead of only one-person. Understanding the interactive mind of two- or multi-person is more complex and higher than understanding the single-person mind in the hierarchical structure of theory of mind. Understanding the interactive mind maybe differentiate from understanding the single mind. In order to examine the dissociative electrophysiological correlates of reading the single mind and reading the interactive mind, the 64 channels event-related potentials were recorded while 16 normal adults were observing three kinds of Chinese idioms depicted physical scenes, one-person with mental activity, and two- or multi-person with mental interaction. After the equivalent N400, in the 500- to 700-ms epoch, the mean amplitudes of late positive component (LPC) over frontal for reading the single mind and reading the interactive mind were significantly more positive than for physical representation, while there was no difference between the former two. In the 700- to 800-ms epoch, the mean amplitudes of LPC over frontal–central for reading the interactive mind were more positive than for reading the single mind and physical representation, while there was no difference between the latter two. The present study provides electrophysiological signature of the dissociations between reading the single mind and reading the interactive mind. PMID:21845178

  20. Electrophysiological correlates of reading the single- and interactive-mind

    Directory of Open Access Journals (Sweden)

    Yi-Wen eWang

    2011-07-01

    Full Text Available Understanding minds is the cognitive basis of successful social interaction. In everyday life, human mental activity often happens at the moment of social interaction among two or multiple persons instead of only one person. Understanding the interactive mind of two- or multi-person is more complex and higher than understanding the single-person mind in the hierarchical structure of theory-of-mind. Understanding the interactive mind maybe differentiate from understanding the single mind. In order to examine the dissociative electrophysiological correlates of reading the single mind and reading the interactive mind, the 64 channels event-related potentials (ERP were recorded while 16 normal adults were observing three kinds of Chinese idioms depicted physical scenes, one-person with mental activity and two- or multi-person with mental interaction. After the equivalent N400, in the 500- to 700-ms epoch, the mean amplitudes of late positive component (LPC over frontal for reading the single mind and reading the interactive mind were significantly more positive than for physical representation, while there was no difference between the former two. In the 700-to 800-ms epoch, the mean amplitudes of LPC over frontal-central for reading the interactive mind were more positive than for reading the single mind and physical representation, while there was no difference between the latter two. The present study provides electrophysiological signature of the dissociations between reading the single mind and reading the interactive mind.

  1. Semiotic Scaffolding in Mathematics

    DEFF Research Database (Denmark)

    Johansen, Mikkel Willum; Misfeldt, Morten

    2015-01-01

    This paper investigates the notion of semiotic scaffolding in relation to mathematics by considering its influence on mathematical activities, and on the evolution of mathematics as a research field. We will do this by analyzing the role different representational forms play in mathematical...... cognition, and more broadly on mathematical activities. In the main part of the paper, we will present and analyze three different cases. For the first case, we investigate the semiotic scaffolding involved in pencil and paper multiplication. For the second case, we investigate how the development of new...... in both mathematical cognition and in the development of mathematics itself, but mathematical cognition cannot itself be reduced to the use of semiotic scaffolding....

  2. Mesenchymal stem cell ingrowth and differentiation on coralline hydroxyapatite scaffolds

    DEFF Research Database (Denmark)

    Mygind, Tina; Stiehler, Maik; Baatrup, Anette

    2007-01-01

    Culture of osteogenic cells on a porous scaffold could offer a new solution to bone grafting using autologous human mesenchymal stem cells (hMSC) from the patient. We compared coralline hydroxyapatite scaffolds with pore sizes of 200 and 500 microm for expansion and differentiation of hMSCs. We...... polymerase chain reaction for 10 osteogenic markers. The 500-microm scaffolds had increased proliferation rates and accommodated a higher number of cells (shown by DNA content, scanning electron microscopy and fluorescence microscopy). Thus the porosity of a 3D microporous biomaterial may be used to steer h......MSC in a particular direction. We found that dynamic spinner flask cultivation of hMSC/scaffold constructs resulted in increased proliferation, differentiation and distribution of cells in scaffolds. Therefore, spinner flask cultivation is an easy-to-use inexpensive system for cultivating hMSCs on small...

  3. The distracted mind on the wheel: Overall propensity to mind wandering is associated with road crash responsibility

    OpenAIRE

    Gil-Jardin?, C?dric; N?e, M?lanie; Lagarde, Emmanuel; Schooler, Jonathan; Contrand, Benjamin; Orriols, Ludivine; Galera, C?dric

    2017-01-01

    The role of distractions on attentional lapses that place road users in higher risk of crash remains poorly understood. We aimed to assess the respective impact of (i) mind wandering trait (propensity to mind wander in the everyday life as measured with a set of 4 questions on the proportion of time spent mind wandering in 4 different situations) and (ii) mind wandering state (disturbing thoughts just before the crash) on road crash risk using a comparison between responsible and non-responsi...

  4. Changing Minds

    International Development Research Centre (IDRC) Digital Library (Canada)

    To make higher education more relevant to the country and society—there are ..... But year after year, the targets for latrine construction were not met, and those ...... This tension provides the energy to do the difficult work that comes from an ...

  5. The effect of scaffold pore size in cartilage tissue engineering.

    Science.gov (United States)

    Nava, Michele M; Draghi, Lorenza; Giordano, Carmen; Pietrabissa, Riccardo

    2016-07-26

    The effect of scaffold pore size and interconnectivity is undoubtedly a crucial factor for most tissue engineering applications. The aim of this study was to examine the effect of pore size and porosity on cartilage construct development in different scaffolds seeded with articular chondrocytes. We fabricated poly-L-lactide-co-trimethylene carbonate scaffolds with different pore sizes, using a solvent-casting/particulate-leaching technique. We seeded primary bovine articular chondrocytes on these scaffolds, cultured the constructs for 2 weeks and examined cell proliferation, viability and cell-specific production of cartilaginous extracellular matrix proteins, including GAG and collagen. Cell density significantly increased up to 50% with scaffold pore size and porosity, likely facilitated by cell spreading on the internal surface of bigger pores, and by increased mass transport of gases and nutrients to cells, and catabolite removal from cells, allowed by lower diffusion barriers in scaffolds with a higher porosity. However, both the cell metabolic activity and the synthesis of cartilaginous matrix proteins significantly decreased by up to 40% with pore size. We propose that the association of smaller pore diameters, causing 3-dimensional cell aggregation, to a lower oxygenation caused by a lower porosity, could have been the condition that increased the cell-specific synthesis of cartilaginous matrix proteins in the scaffold with the smallest pores and the lowest porosity among those tested. In the initial steps of in vitro cartilage engineering, the combination of small scaffold pores and low porosity is an effective strategy with regard to the promotion of chondrogenesis.

  6. Human Mind Maps

    Science.gov (United States)

    Glass, Tom

    2016-01-01

    When students generate mind maps, or concept maps, the maps are usually on paper, computer screens, or a blackboard. Human Mind Maps require few resources and little preparation. The main requirements are space where students can move around and a little creativity and imagination. Mind maps can be used for a variety of purposes, and Human Mind…

  7. Bone tissue engineering scaffolding: computer-aided scaffolding techniques.

    Science.gov (United States)

    Thavornyutikarn, Boonlom; Chantarapanich, Nattapon; Sitthiseripratip, Kriskrai; Thouas, George A; Chen, Qizhi

    Tissue engineering is essentially a technique for imitating nature. Natural tissues consist of three components: cells, signalling systems (e.g. growth factors) and extracellular matrix (ECM). The ECM forms a scaffold for its cells. Hence, the engineered tissue construct is an artificial scaffold populated with living cells and signalling molecules. A huge effort has been invested in bone tissue engineering, in which a highly porous scaffold plays a critical role in guiding bone and vascular tissue growth and regeneration in three dimensions. In the last two decades, numerous scaffolding techniques have been developed to fabricate highly interconnective, porous scaffolds for bone tissue engineering applications. This review provides an update on the progress of foaming technology of biomaterials, with a special attention being focused on computer-aided manufacturing (Andrade et al. 2002) techniques. This article starts with a brief introduction of tissue engineering (Bone tissue engineering and scaffolds) and scaffolding materials (Biomaterials used in bone tissue engineering). After a brief reviews on conventional scaffolding techniques (Conventional scaffolding techniques), a number of CAM techniques are reviewed in great detail. For each technique, the structure and mechanical integrity of fabricated scaffolds are discussed in detail. Finally, the advantaged and disadvantage of these techniques are compared (Comparison of scaffolding techniques) and summarised (Summary).

  8. The protective effects of brief mindfulness meditation training.

    Science.gov (United States)

    Banks, Jonathan B; Welhaf, Matthew S; Srour, Alexandra

    2015-05-01

    Mindfulness meditation has gained a great deal of attention in recent years due to the variety of physical and psychological benefits, including improved working memory, decreased mind wandering and reduced impact of stress on working memory. The current study examined a 1-week at home mindfulness meditation intervention compared to an active control intervention. Results suggest that mindfulness meditation does not increase working memory or decrease mind wandering but does prevent stress related working memory impairments. Mindfulness meditation appears to alter the factors that impair working memory such that the negative impact of mind wandering on working memory was only evident at higher levels of negative affect. The use of cognitive mechanism words in narratives of stressful events did not differ by condition but predicted poorer working memory in the control condition. The results support the use of an at home mindfulness meditation intervention for reducing stress-related impairments. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Driving with the wandering mind: the effect that mind-wandering has on driving performance.

    Science.gov (United States)

    Yanko, Matthew R; Spalek, Thomas M

    2014-03-01

    The principal objective of the present work was to examine the effects of mind state (mind-wandering vs. on-task) on driving performance in a high-fidelity driving simulator. Mind-wandering is thought to interfere with goal-directed thought. It is likely, then, that when driving, mind-wandering might lead to impairments in critical aspects of driving performance. In two experiments, we assess the extent to which mind-wandering interferes with responsiveness to sudden events, mean velocity, and headway distance. Using a car-following procedure in a high-fidelity driving simulator, participants were probed at random times to indicate whether they were on-task at that moment or mind-wandering. The dependent measures were analyzed based on the participant's response to the probe. Compared to when on-task, when mind-wandering participants showed longer response times to sudden events, drove at a higher velocity, and maintained a shorter headway distance. Collectively, these findings indicate that mind-wandering affects a broad range of driving responses and may therefore lead to higher crash risk. The results suggest that situations that are likely associated with mind-wandering (e.g., route familiarity) can impair driving performance.

  10. The External Mind

    DEFF Research Database (Denmark)

    , Extended Mind and Distributed Cognition by Claudio Paolucci pp. 69-96 The Social Horizon of Embodied Language and Material Symbols by Riccardo Fusaroli pp. 97-123 Semiotics and Theories of Situated/Distributed Action and Cognition: a Dialogue and Many Intersections by Tommaso Granelli pp. 125-167 Building......The External Mind: an Introduction by Riccardo Fusaroli, Claudio Paolucci pp. 3-31 The sign of the Hand: Symbolic Practices and the Extended Mind by Massimiliano Cappuccio, Michael Wheeler pp. 33-55 The Overextended Mind by Shaun Gallagher pp. 57-68 The "External Mind": Semiotics, Pragmatism...

  11. Mindfulness og mental sundhed

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2011-01-01

    Mindfulness is a way to practice 'healthy mindedness' – a form of self help that has been the subject for research and development of a number of new significant self-technologies, therapy and meditation treatment methods. To be mindful can help people to feel more relaxed (serenity) and fully...... alive. The article aims at describing realistic expectations to the contribution of mindfulness to health education work in the field of mental health. The article discuss ways in which mindfulnesss is connected with established health education in the mental health promotion field, and ways in which...... mindfulness breaks with established health education. Interest in utilising mindfulness and mindfulness-inspired methods in health-education intervention has increased in recent years. Mindfulness is seen here as an answer to how to achieve more accepting presence, and thereby a healthier mental life...

  12. Gelatin Scaffolds with Controlled Pore Structure and Mechanical Property for Cartilage Tissue Engineering.

    Science.gov (United States)

    Chen, Shangwu; Zhang, Qin; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping

    2016-03-01

    Engineering of cartilage tissue in vitro using porous scaffolds and chondrocytes provides a promising approach for cartilage repair. However, nonuniform cell distribution and heterogeneous tissue formation together with weak mechanical property of in vitro engineered cartilage limit their clinical application. In this study, gelatin porous scaffolds with homogeneous and open pores were prepared using ice particulates and freeze-drying. The scaffolds were used to culture bovine articular chondrocytes to engineer cartilage tissue in vitro. The pore structure and mechanical property of gelatin scaffolds could be well controlled by using different ratios of ice particulates to gelatin solution and different concentrations of gelatin. Gelatin scaffolds prepared from ≥70% ice particulates enabled homogeneous seeding of bovine articular chondrocytes throughout the scaffolds and formation of homogeneous cartilage extracellular matrix. While soft scaffolds underwent cellular contraction, stiff scaffolds resisted cellular contraction and had significantly higher cell proliferation and synthesis of sulfated glycosaminoglycan. Compared with the gelatin scaffolds prepared without ice particulates, the gelatin scaffolds prepared with ice particulates facilitated formation of homogeneous cartilage tissue with significantly higher compressive modulus. The gelatin scaffolds with highly open pore structure and good mechanical property can be used to improve in vitro tissue-engineered cartilage.

  13. Magnetic responsive hydroxyapatite composite scaffolds construction for bone defect reparation

    Directory of Open Access Journals (Sweden)

    Zeng XB

    2012-07-01

    Full Text Available Xiao Bo Zeng, Hao Hu, Li Qin Xie, Fang Lan, Wen Jiang, Yao Wu, Zhong Wei GuNational Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan, People's Republic of ChinaIntroduction: In recent years, interest in magnetic biomimetic scaffolds for tissue engineering has increased considerably. A type of magnetic scaffold composed of magnetic nanoparticles (MNPs and hydroxyapatite (HA for bone repair has been developed by our research group.Aim and methods: In this study, to investigate the influence of the MNP content (in the scaffolds on the cell behaviors and the interactions between the magnetic scaffold and the exterior magnetic field, a series of MNP-HA magnetic scaffolds with different MNP contents (from 0.2% to 2% were fabricated by immersing HA scaffold into MNP colloid. ROS 17/2.8 and MC3T3-E1 cells were cultured on the scaffolds in vitro, with and without an exterior magnetic field, respectively. The cell adhesion, proliferation and differentiation were evaluated via scanning electron microscopy; confocal laser scanning microscopy; and 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT, alkaline phosphatase, and bone gla protein activity tests.Results: The results demonstrated the positive influence of the magnetic scaffolds on cell adhesion, proliferation, and differentiation. Further, a higher amount of MNPs on the magnetic scaffolds led to more significant stimulation.Conclusion: The magnetic scaffold can respond to the exterior magnetic field and engender some synergistic effect to intensify the stimulating effect of a magnetic field to the proliferation and differentiation of cells.Keywords: magnetic therapy, magnetic nanoparticles, bone repair, magnetic responsive

  14. Development of porous Ti6Al4V/chitosan sponge composite scaffold for orthopedic applications

    International Nuclear Information System (INIS)

    Guo, Miao; Li, Xiang

    2016-01-01

    A novel composite scaffold consisting of porous Ti6Al4V part filled with chitosan sponge was fabricated using a combination of electron beam melting and freeze-drying. The mechanical properties of porous Ti6Al4V part were examined via compressive test. The ultimate compressive strength was 85.35 ± 8.68 MPa and the compressive modulus was 2.26 ± 0.42 GPa. The microstructure of composite scaffold was characterized using scanning electron microscopy. The chitosan sponge filled in Ti6Al4V part exhibited highly porous and well-interconnected micro-pore architecture. The osteoblastic cells were seeded on scaffolds to test their seeding efficiency and biocompatibility. Significantly higher cell seeding efficiency was found on composite scaffold. The biological response of osteoblasts on composite scaffolds was superior in terms of improved cell attachment, higher proliferation, and well-spread morphology in relation to porous Ti6Al4V part. These results suggest that the Ti6Al4V/chitosan composite scaffold is potentially useful as a biomedical scaffold for orthopedic applications. - Highlights: • A novel composite scaffold with sufficient mechanical properties and favorable cell affinity environment was developed. • Significantly higher cell seeding efficiency was found on composite scaffold. • The osteoblasts on composite scaffolds showed well-spread morphology, improved cell attachment and higher proliferation.

  15. Development of Collagen/Demineralized Bone Powder Scaffolds and Periosteum-Derived Cells for Bone Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Wilairat Leeanansaksiri

    2013-01-01

    Full Text Available The aim of this study was to investigate physical and biological properties of collagen (COL and demineralized bone powder (DBP scaffolds for bone tissue engineering. DBP was prepared and divided into three groups, based on various particle sizes: 75–125 µm, 125–250 µm, and 250–500 µm. DBP was homogeneously mixed with type I collagen and three-dimensional scaffolds were constructed, applying chemical crosslinking and lyophilization. Upon culture with human periosteum-derived cells (PD cells, osteogenic differentiation of PD cells was investigated using alkaline phosphatase (ALP activity and calcium assay kits. The physical properties of the COL/DBP scaffolds were obviously different from COL scaffolds, irrespective of the size of DBP. In addition, PD cells cultured with COL scaffolds showed significantly higher cell adhesion and proliferation than those with COL/DBP scaffolds. In contrast, COL/DBP scaffolds exhibited greater osteoinductive potential than COL scaffolds. The PD cells with COL/DBP scaffolds possessed higher ALP activity than those with COL scaffolds. PD cells cultured with COL/DBP scaffolds with 250–500 mm particle size yielded the maximum calcium deposition. In conclusion, PD cells cultured on the scaffolds could exhibit osteoinductive potential. The composite scaffold of COL/DBP with 250–500 mm particle size could be considered a potential bone tissue engineering implant.

  16. Biomimetic composite coating on rapid prototyped scaffolds for bone tissue engineering.

    Science.gov (United States)

    Arafat, M Tarik; Lam, Christopher X F; Ekaputra, Andrew K; Wong, Siew Yee; Li, Xu; Gibson, Ian

    2011-02-01

    The objective of this present study was to improve the functional performance of rapid prototyped scaffolds for bone tissue engineering through biomimetic composite coating. Rapid prototyped poly(ε-caprolactone)/tri-calcium phosphate (PCL/TCP) scaffolds were fabricated using the screw extrusion system (SES). The fabricated PCL/TCP scaffolds were coated with a carbonated hydroxyapatite (CHA)-gelatin composite via biomimetic co-precipitation. The structure of the prepared CHA-gelatin composite coating was studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Compressive mechanical testing revealed that the coating process did not have any detrimental effect on the mechanical properties of the scaffolds. The cell-scaffold interaction was studied by culturing porcine bone marrow stromal cells (BMSCs) on the scaffolds and assessing the proliferation and bone-related gene and protein expression capabilities of the cells. Confocal laser microscopy and SEM images of the cell-scaffold constructs showed a uniformly distributed cell sheet and accumulation of extracellular matrix in the interior of CHA-gelatin composite-coated PCL/TCP scaffolds. The proliferation rate of BMSCs on CHA-gelatin composite-coated PCL/TCP scaffolds was about 2.3 and 1.7 times higher than that on PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds, respectively, by day 10. Furthermore, reverse transcription polymerase chain reaction and Western blot analysis revealed that CHA-gelatin composite-coated PCL/TCP scaffolds stimulate osteogenic differentiation of BMSCs the most, compared with PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds. These results demonstrate that CHA-gelatin composite-coated rapid prototyped PCL/TCP scaffolds are promising for bone tissue engineering. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Scaffolding students’ assignments

    DEFF Research Database (Denmark)

    Slot, Marie Falkesgaard

    2013-01-01

    This article discusses scaffolding in typical student assignments in mother tongue learning materials in upper secondary education in Denmark and the United Kingdom. It has been determined that assignments do not have sufficient scaffolding end features to help pupils understand concepts and build...... objects. The article presents the results of empirical research on tasks given in Danish and British learning materials. This work is based on a further development of my PhD thesis: “Learning materials in the subject of Danish” (Slot 2010). The main focus is how cognitive models (and subsidiary explicit...... learning goals) can help students structure their argumentative and communica-tive learning processes, and how various multimodal representations can give more open-ended learning possibilities for collaboration. The article presents a short introduction of the skills for 21st century learning and defines...

  18. Mindfulness - en implicit utopi?

    DEFF Research Database (Denmark)

    Nielsen, Anne Maj

    2014-01-01

    The field of mindfulness and meditation has met growing interest in the western world during the last decades. Mindfulness aims to develop a friendly, accepting and mindful awareness in the present moment. Critiques have argued that this aim is deployed in a new kind of management technology where...... mindfulness is used for individualized stress-reduction in order to keep up with existing or worsened working conditions instead of stress-reducing changes in the common working conditions. Mindfulness research emphasizes positive outcomes in coping with demands and challenges in everyday life especially...... considering suffering (for example stress and pain). While explicit constructions of Utopia present ideas of specific societal communities in well-functioning harmony, the interest in mindfulness can in contradistinction be considered an implicit critique of present life-conditions and an “implicit utopia...

  19. Cell-derived matrix coatings for polymeric scaffolds.

    Science.gov (United States)

    Decaris, Martin L; Binder, Bernard Y; Soicher, Matthew A; Bhat, Archana; Leach, J Kent

    2012-10-01

    Cells in culture deposit a complex extracellular matrix that remains intact following decellularization and possesses the capacity to modulate cell phenotype. The direct application of such decellularized matrices (DMs) to 3D substrates is problematic, as transport issues influence the homogeneous deposition, decellularization, and modification of DM surface coatings. In an attempt to address this shortcoming, we hypothesized that DMs deposited by human mesenchymal stem cells (MSCs) could be transferred to the surface of polymeric scaffolds while maintaining their capacity to direct cell fate. The ability of the transferred DM (tDM)-coated scaffolds to enhance the osteogenic differentiation of undifferentiated and osteogenically induced MSCs under osteogenic conditions in vitro was confirmed. tDM-coated scaffolds increased MSC expression of osteogenic marker genes (BGLAP, IBSP) and intracellular alkaline phosphatase production. In addition, undifferentiated MSCs deposited significantly more calcium when seeded onto tDM-coated scaffolds compared with control scaffolds. MSC-seeded tDM-coated scaffolds subcutaneously implanted in nude rats displayed significantly higher blood vessel density after 2 weeks compared with cells on uncoated scaffolds, but we did not observe significant differences in mineral deposition after 8 weeks. These data demonstrate that DM-coatings produced in 2D culture can be successfully transferred to 3D substrates and retain their capacity to modulate cell phenotype.

  20. Microwell Scaffolds for the Extrahepatic Transplantation of Islets of Langerhans

    Science.gov (United States)

    Buitinga, Mijke; Truckenmüller, Roman; Engelse, Marten A.; Moroni, Lorenzo; Ten Hoopen, Hetty W. M.; van Blitterswijk, Clemens A.; de Koning, Eelco JP.; van Apeldoorn, Aart A.; Karperien, Marcel

    2013-01-01

    Allogeneic islet transplantation into the liver has the potential to restore normoglycemia in patients with type 1 diabetes. However, the suboptimal microenvironment for islets in the liver is likely to be involved in the progressive islet dysfunction that is often observed post-transplantation. This study validates a novel microwell scaffold platform to be used for the extrahepatic transplantation of islet of Langerhans. Scaffolds were fabricated from either a thin polymer film or an electrospun mesh of poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT) block copolymer (composition: 4000PEOT30PBT70) and were imprinted with microwells, ∼400 µm in diameter and ∼350 µm in depth. The water contact angle and water uptake were 39±2° and 52.1±4.0 wt%, respectively. The glucose flux through electrospun scaffolds was three times higher than for thin film scaffolds, indicating enhanced nutrient diffusion. Human islets cultured in microwell scaffolds for seven days showed insulin release and insulin content comparable to those of free-floating control islets. Islet morphology and insulin and glucagon expression were maintained during culture in the microwell scaffolds. Our results indicate that the microwell scaffold platform prevents islet aggregation by confinement of individual islets in separate microwells, preserves the islet’s native rounded morphology, and provides a protective environment without impairing islet functionality, making it a promising platform for use in extrahepatic islet transplantation. PMID:23737999

  1. Membrane-reinforced three-dimensional electrospun silk fibroin scaffolds for bone tissue engineering

    International Nuclear Information System (INIS)

    Yang, Sung Yeun; Hwang, Tae Heon; Ryu, WonHyoung; Che, Lihua; Oh, Jin Soo; Ha, Yoon

    2015-01-01

    Electrospun silk fibroin (SF) scaffolds have drawn much attention because of their resemblance to natural tissue architecture such as extracellular matrix, and the biocompatibility of SF as a candidate material to replace collagen. However, electrospun scaffolds lack the physical integrity of bone tissue scaffolds, which require resistance to mechanical loadings. In this work, we propose membrane-reinforced electrospun SF scaffolds by a serial process of electrospinning and freeze-drying of SF solutions in two different solvents: formic acid and water, respectively. After wet electrospinning followed by replacement of methanol with water, SF nanofibers dispersed in water were mixed with aqueous SF solution. Freeze-drying of the mixed solution resulted in 3D membrane-connected SF nanofibrous scaffolds (SF scaffolds) with a thickness of a few centimeters. We demonstrated that the SF concentration of aqueous SF solution controlled the degree of membrane reinforcement between nanofibers. It was also shown that both increase in degree of membrane reinforcement and inclusion of hydroxyapatite (HAP) nanoparticles resulted in higher resistance to compressive loadings of the SF scaffolds. Culture of human osteoblasts on collagen, SF, and SF-HAP scaffolds showed that both SF and SF-HAP scaffolds had biocompatibility and cell proliferation superior to that of the collagen scaffolds. SF-HAP scaffolds with and without BMP-2 were used for in vivo studies for 4 and 8 weeks, and they showed enhanced bone tissue formation in rat calvarial defect models. (paper)

  2. Tough and flexible CNT-polymeric hybrid scaffolds for engineering cardiac constructs.

    Science.gov (United States)

    Kharaziha, Mahshid; Shin, Su Ryon; Nikkhah, Mehdi; Topkaya, Seda Nur; Masoumi, Nafiseh; Annabi, Nasim; Dokmeci, Mehmet R; Khademhosseini, Ali

    2014-08-01

    In the past few years, a considerable amount of effort has been devoted toward the development of biomimetic scaffolds for cardiac tissue engineering. However, most of the previous scaffolds have been electrically insulating or lacked the structural and mechanical robustness to engineer cardiac tissue constructs with suitable electrophysiological functions. Here, we developed tough and flexible hybrid scaffolds with enhanced electrical properties composed of carbon nanotubes (CNTs) embedded aligned poly(glycerol sebacate):gelatin (PG) electrospun nanofibers. Incorporation of varying concentrations of CNTs from 0 to 1.5% within the PG nanofibrous scaffolds (CNT-PG scaffolds) notably enhanced fiber alignment and improved the electrical conductivity and toughness of the scaffolds while maintaining the viability, retention, alignment, and contractile activities of cardiomyocytes (CMs) seeded on the scaffolds. The resulting CNT-PG scaffolds resulted in stronger spontaneous and synchronous beating behavior (3.5-fold lower excitation threshold and 2.8-fold higher maximum capture rate) compared to those cultured on PG scaffold. Overall, our findings demonstrated that aligned CNT-PG scaffold exhibited superior mechanical properties with enhanced CM beating properties. It is envisioned that the proposed hybrid scaffolds can be useful for generating cardiac tissue constructs with improved organization and maturation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Steering Your Mysterious Mind

    DEFF Research Database (Denmark)

    Prasad, Ramjee

    Steering the Mysterious Mind, describes a unique, novel concept for a way to gain control of your mind. The five basic elements of human life, that is; Creativity, Content­ment, Confidence, Calmness, and Concentration (C5) have been introduced in my previous book Unlock Your Personalization. Posi....... Compare it with going to the gym where you work on the physical body. In the same way as with arms and legs, the mind is a mus­cle which you exercise through C5 practice. Steering the mind on your personal goal will help you to be creative....

  4. A Mind of Three Minds: Evolution of the Human Brain

    Science.gov (United States)

    MacLean, Paul D.

    1978-01-01

    The author examines the evolutionary and neural roots of a triune intelligence comprised of a primal mind, an emotional mind, and a rational mind. A simple brain model and some definitions of unfamiliar behavioral terms are included. (Author/MA)

  5. Enhanced chondrogenesis of human nasal septum derived progenitors on nanofibrous scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Shafiee, Abbas [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Stem Cell biology and Tissue Engineering Departments, Stem Cell Technology Research Center, Tehran (Iran, Islamic Republic of); Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, QLD (Australia); Seyedjafari, Ehsan [Department of Biotechnology, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Sadat Taherzadeh, Elham [Stem Cell biology and Tissue Engineering Departments, Stem Cell Technology Research Center, Tehran (Iran, Islamic Republic of); Dinarvand, Peyman [Stem Cell biology and Tissue Engineering Departments, Stem Cell Technology Research Center, Tehran (Iran, Islamic Republic of); The Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO (United States); Soleimani, Masoud [Hematology Department, Faculty of Medical Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Ai, Jafar, E-mail: jafar_ai@tums.ac.ir [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Brain and Spinal Injury Research Center, Imam Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-07-01

    Topographical cues can be exploited to regulate stem cell attachment, proliferation, differentiation and function in vitro and in vivo. In this study, we aimed to investigate the influence of different nanofibrous topographies on the chondrogenic differentiation potential of nasal septum derived progenitors (NSP) in vitro. Aligned and randomly oriented Ploy (L-lactide) (PLLA)/Polycaprolactone (PCL) hybrid scaffolds were fabricated via electrospinning. First, scaffolds were fully characterized, and then NSP were seeded on them to study their capacity to support stem cell attachment, proliferation and chondrogenic differentiation. Compared to randomly oriented nanofibers, aligned scaffolds showed a high degree of nanofiber alignment with much better tensile strength properties. Both scaffolds supported NSP adhesion, proliferation and chondrogenic differentiation. Despite the higher rate of cell proliferation on random scaffolds, a better chondrogenic differentiation was observed on aligned nanofibers as deduced from higher expression of chondrogenic markers such as collagen type II and aggrecan on aligned scaffolds. These findings demonstrate that electrospun constructs maintain NSP proliferation and differentiation, and that the aligned nanofibrous scaffolds can significantly enhance chondrogenic differentiation of nasal septum derived progenitors. - Highlights: • Electrospun nanofiber scaffolds with different topographies were fabricated. • Aligned nanofiber scaffolds had better tensile strength properties. • Nasal septum derived progenitors were cultured on nanofibrous scaffolds. • Both topographies support proliferation and chondrogenic differentiation. • Better chondrogenic differentiation was observed on aligned nanofibers.

  6. Enhanced chondrogenesis of human nasal septum derived progenitors on nanofibrous scaffolds

    International Nuclear Information System (INIS)

    Shafiee, Abbas; Seyedjafari, Ehsan; Sadat Taherzadeh, Elham; Dinarvand, Peyman; Soleimani, Masoud; Ai, Jafar

    2014-01-01

    Topographical cues can be exploited to regulate stem cell attachment, proliferation, differentiation and function in vitro and in vivo. In this study, we aimed to investigate the influence of different nanofibrous topographies on the chondrogenic differentiation potential of nasal septum derived progenitors (NSP) in vitro. Aligned and randomly oriented Ploy (L-lactide) (PLLA)/Polycaprolactone (PCL) hybrid scaffolds were fabricated via electrospinning. First, scaffolds were fully characterized, and then NSP were seeded on them to study their capacity to support stem cell attachment, proliferation and chondrogenic differentiation. Compared to randomly oriented nanofibers, aligned scaffolds showed a high degree of nanofiber alignment with much better tensile strength properties. Both scaffolds supported NSP adhesion, proliferation and chondrogenic differentiation. Despite the higher rate of cell proliferation on random scaffolds, a better chondrogenic differentiation was observed on aligned nanofibers as deduced from higher expression of chondrogenic markers such as collagen type II and aggrecan on aligned scaffolds. These findings demonstrate that electrospun constructs maintain NSP proliferation and differentiation, and that the aligned nanofibrous scaffolds can significantly enhance chondrogenic differentiation of nasal septum derived progenitors. - Highlights: • Electrospun nanofiber scaffolds with different topographies were fabricated. • Aligned nanofiber scaffolds had better tensile strength properties. • Nasal septum derived progenitors were cultured on nanofibrous scaffolds. • Both topographies support proliferation and chondrogenic differentiation. • Better chondrogenic differentiation was observed on aligned nanofibers

  7. Novel fiber-based pure chitosan scaffold for tendon augmentation: biomechanical and cell biological evaluation.

    Science.gov (United States)

    Nowotny, J; Aibibu, D; Farack, J; Nimtschke, U; Hild, M; Gelinsky, M; Kasten, P; Cherif, Ch

    2016-07-01

    One possibility to improve the mechanical properties after tendon ruptures is augmentation with a scaffold. Based on wet spinning technology, chitosan fibres were processed to a novel pure high-grade multifilament yarn with reproducible quality. The fibres were braided to obtain a 3D tendon scaffold. The CS fibres and scaffolds were evaluated biomechanically and compared to human supraspinatus (SSP) tendons. For the cytobiological characterization, in vitro cell culture experiments with human mesenchymal stem cells (hMSC) were performed. Three types of 3D circular braided scaffolds were fabricated. Significantly, higher ultimate stress values were measured for scaffold with larger filament yarn, compared to scaffold with smaller filament yarn. During cultivation over 28 days, the cells showed in dependence of isolation method and/or donor a doubling or tripling of the cell number or even a six-fold increase on the CS scaffold, which was comparable to the control (polystyrene) or in the case of cells obtained from human biceps tendon even higher proliferation rates. After 14 days, the scaffold surface was covered homogeneously with a cell layer. In summary, the present work demonstrates that braided chitosan scaffolds constitute a straightforward approach for designing tendon analogues, maintaining important flexibility in scaffold design and providing favourable mechanical properties of the resulting construct.

  8. A novel nano-structured porous polycaprolactone scaffold improves hyaline cartilage repair in a rabbit model compared to a collagen type I/III scaffold: in vitro and in vivo studies.

    Science.gov (United States)

    Christensen, Bjørn Borsøe; Foldager, Casper Bindzus; Hansen, Ole Møller; Kristiansen, Asger Albæk; Le, Dang Quang Svend; Nielsen, Agnete Desirée; Nygaard, Jens Vinge; Bünger, Cody Erik; Lind, Martin

    2012-06-01

    To develop a nano-structured porous polycaprolactone (NSP-PCL) scaffold and compare the articular cartilage repair potential with that of a commercially available collagen type I/III (Chondro-Gide) scaffold. By combining rapid prototyping and thermally induced phase separation, the NSP-PCL scaffold was produced for matrix-assisted autologous chondrocyte implantation. Lyophilizing a water-dioxane-PCL solution created micro and nano-pores. In vitro: The scaffolds were seeded with rabbit chondrocytes and cultured in hypoxia for 6 days. qRT-PCR was performed using primers for sox9, aggrecan, collagen type 1 and 2. In vivo: 15 New Zealand White Rabbits received bilateral osteochondral defects in the femoral intercondylar grooves. Autologous chondrocytes were harvested 4 weeks prior to surgery. There were 3 treatment groups: (1) NSP-PCL scaffold without cells. (2) The Chondro-Gide scaffold with autologous chondrocytes and (3) NSP-PCL scaffold with autologous chondrocytes. Observation period was 13 weeks. Histological evaluation was made using the O'Driscoll score. In vitro: The expressions of sox9 and aggrecan were higher in the NSP-PCL scaffold, while expression of collagen 1 was lower compared to the Chondro-Gide scaffold. In vivo: Both NSP-PCL scaffolds with and without cells scored significantly higher than the Chondro-Gide scaffold when looking at the structural integrity and the surface regularity of the repair tissue. No differences were found between the NSP-PCL scaffold with and without cells. The NSP-PCL scaffold demonstrated higher in vitro expression of chondrogenic markers and had higher in vivo histological scores compared to the Chondro-Gide scaffold. The improved chondrocytic differentiation can potentially produce more hyaline cartilage during clinical cartilage repair. It appears to be a suitable cell-free implant for hyaline cartilage repair and could provide a less costly and more effective treatment option than the Chondro-Gide scaffold with cells.

  9. Poly (hydroxybutyrate co hydroxyvalerate Nanofibrous Scaffold Containing HydroxyapatiteBredigite Nanoparticles: Characterization and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    M. Kouhi

    2017-11-01

    Full Text Available In this work, poly (hydroxybutyrate co hydroxyvalerate (PHBV composite nanofibrous scaffold containing hydroxyapatite/bredigite (HABR nanoparticles was fabricated through electrospining method. The morphology of prepared  nanofibers and the state of the nanoparticles dispersion in nanofiber matrix were investigated using scanning and transmission electron microscopy, respectively. Evaluation of the mechanical properties of the nanofibrous scaffolds revealed that there is a limit to the nanoparticle concentration at which nanoparticles can improve the mechanical properties of the nanofibrous scaffolds. According to the results, PHBV/HABR nanofibers showed higher wettability compared to PHBV nanofibers. In vitro cell culture assay was done using human fetal osteoblast cells on nanofibrous scaffold. MTS assay revealed that cell proliferation on the composite nanofibrous scaffold was significantly higher than those on the pure scaffold after 10 and 15 days. Scanning electron microscopy- Energy dispersive X-ray spectroscopy and CMFDA colorimeter assay analysis showed that the cells on the PHBV/HABR scaffolds acquired higher mineral deposition than the cells on the pure PHBV and control sample scaffold. Based on the results we concluded that PHBV/HABR nanofibers scaffold with higher wettability, improved mechanical properties and cell behavior hold great potential in bone regeneration applications.

  10. Understanding Resident Performance, Mindfulness, and Communication in Critical Care Rotations.

    Science.gov (United States)

    Real, Kevin; Fields-Elswick, Katelyn; Bernard, Andrew C

    Evidence from the medical literature suggests that surgical trainees can benefit from mindful practices. Surgical educators are challenged with the need to address resident core competencies, some of which may be facilitated by higher levels of mindfulness. This study explores whether mindful residents perform better than their peers as members of the health care team. This study employed a multiphase, multimethod design to assess resident mindfulness, communication, and clinical performance. Academic, tertiary medical center. Residents (N = 51) working in an intensive care unit. In phase I, medical residents completed a self-report survey of mindfulness, communication, emotional affect, and clinical decision-making. In phase II, resident performance was assessed using independent ratings of mindfulness and clinical decision-making by attending physicians and registered nurses. In phase 1, a significant positive relationship was found between resident performance and mindfulness, positive affect (PA), and communication. In phase 2, attending physicians/registered nurses' perceptions of residents' mindfulness were positively correlated with communication and inversely related to negative affect (NA). The top quartile of residents for performance and mindfulness had the lowest NA. Higher-rated residents underestimated their performance/mindfulness, whereas those in the lowest quartile overestimated these factors. This study offers a number of implications for medical resident education. First, mindfulness was perceived to be a significant contributor to self-assessments of competency and performance. Second, both PA and NA were important to mindfulness and performance. Third, communication was associated with resident performance, mindfulness, and PA. These implications suggest that individual characteristics of mindfulness, communication, and affect, all potentially modifiable, influence care quality and safety. To improve low performers, surgical educators could

  11. Mindfulness and Student Success

    Science.gov (United States)

    Leland, Matt

    2015-01-01

    Mindfulness has long been practiced in Eastern spiritual traditions for personal improvement, and educators and educational institutions have recently begun to explore its usefulness in schools. Mindfulness training can be valuable for helping students be more successful learners and more connected members of an educational community. To determine…

  12. Restless Mind, Restless Body

    Science.gov (United States)

    Seli, Paul; Carriere, Jonathan S. A.; Thomson, David R.; Cheyne, James Allan; Martens, Kaylena A. Ehgoetz; Smilek, Daniel

    2014-01-01

    In the present work, we investigate the hypothesis that failures of task-related executive control that occur during episodes of mind wandering are associated with an increase in extraneous movements (fidgeting). In 2 studies, we assessed mind wandering using thought probes while participants performed the metronome response task (MRT), which…

  13. Elliott on Mind Matters.

    Science.gov (United States)

    Maattanen, Pentti

    2000-01-01

    Argues that David Elliott's conception of the human mind presented in his book "Music Matters" is not coherent. Outlines three alternatives to Elliott's theory of mind. Suggests that the principles associated with the pragmatism of Charles Sanders Pierce would complement Elliott's ideas in his book. (CMK)

  14. Mindfulness at Cam

    OpenAIRE

    Jones, Peter Brian; Dufour, G; Galante, Julieta; English, E

    2016-01-01

    The University of Cambridge and the National Institute for Health Research and Collaboration for Leadership in Applied Health Research and Care (NIHR CLAHRC), East of England, are currently undertaking research into the effectiveness of mindfulness as a way of combatting student stress. In this article, various stakeholders in the project describe its purpose, its focus, and the delivery of mindfulness sessions to students.

  15. Resisting Mind Control.

    Science.gov (United States)

    Anderson, Susan M.; Zimbardo, Philip G.

    1980-01-01

    Provides conceptual analyses of mind control techniques along with practical advice on how to resist these techniques. The authors stress that effective mind control stems more from everyday social relations than from exotic technological gimmicks. Suggestions are given for resisting persuasion, resisting systems, and challenging the system.…

  16. Text 2 Mind Map

    OpenAIRE

    Iona, John

    2017-01-01

    This is a review of the web resource 'Text 2 Mind Map' www.Text2MindMap.com. It covers what the resource is, and how it might be used in Library and education context, in particular for School Librarians.

  17. Mind Your Risks

    Science.gov (United States)

    ... ZIP 223KB Social Media Graphics Download .ZIP 293KB Social Media Graphics CAMPAIGN RESOURCES: SOCIAL MEDIA GRAPHICS Mind Your Risks® (MYR) ... ZIP 360KB Social Media Graphics Download .ZIP 433KB Social Media Graphics CAMPAIGN RESOURCES: SOCIAL MEDIA GRAPHICS Mind Your Risks® (MYR) ...

  18. Nerve regeneration using tubular scaffolds from biodegradable polyurethane.

    Science.gov (United States)

    Hausner, T; Schmidhammer, R; Zandieh, S; Hopf, R; Schultz, A; Gogolewski, S; Hertz, H; Redl, H

    2007-01-01

    differences. There was a higher level of collagenic connective tissue within the scaffold and within the distal nerve stump. Schwann cells migrated into the polyurethane scaffold. There was no statistical difference to the nerve graft group although Schwann cell counts were lower especially within the middle of the polyurethane scaffold. Axon counts showed a trend-wise decrease within the scaffold. These results suggest that biodegradable polyurethane tubular scaffolds coated with diluted fibrin sealant support peripheral nerve regeneration in a standard gap model in the rat up to 3 months. Three months after surgery no sign of degradation could be seen.

  19. A Moment of Mindfulness: Computer-Mediated Mindfulness Practice Increases State Mindfulness

    OpenAIRE

    Mahmood, L.; Hopthrow, T.; Randsley de Moura, G.

    2016-01-01

    Three studies investigated the use of a 5-minute, computer-mediated mindfulness practice in increasing levels of state mindfulness. In Study 1, 54 high school students completed the computer-mediated mindfulness practice in a lab setting and Toronto Mindfulness Scale (TMS) scores were measured before and after the practice. In Study 2 (N = 90) and Study 3 (N = 61), the mindfulness practice was tested with an entirely online sample to test the delivery of the 5-minute mindfulness practice via ...

  20. Preparation and Evaluation of Gelatin-Chitosan-Nanobioglass 3D Porous Scaffold for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Kanchan Maji

    2016-01-01

    Full Text Available The aim of the present study was to prepare and characterize bioglass-natural biopolymer based composite scaffold and evaluate its bone regeneration ability. Bioactive glass nanoparticles (58S in the size range of 20–30 nm were synthesized using sol-gel method. Porous scaffolds with varying bioglass composition from 10 to 30 wt% in chitosan, gelatin matrix were fabricated using the method of freeze drying of its slurry at 40 wt% solids loading. Samples were cross-linked with glutaraldehyde to obtain interconnected porous 3D microstructure with improved mechanical strength. The prepared scaffolds exhibited >80% porosity with a mean pore size range between 100 and 300 microns. Scaffold containing 30 wt% bioglass (GCB 30 showed a maximum compressive strength of 2.2±0.1 MPa. Swelling and degradation studies showed that the scaffold had excellent properties of hydrophilicity and biodegradability. GCB 30 scaffold was shown to be noncytotoxic and supported mesenchymal stem cell attachment, proliferation, and differentiation as indicated by MTT assay and RUNX-2 expression. Higher cellular activity was observed in GCB 30 scaffold as compared to GCB 0 scaffold suggesting the fact that 58S bioglass nanoparticles addition into the scaffold promoted better cell adhesion, proliferation, and differentiation. Thus, the study showed that the developed composite scaffolds are potential candidates for regenerating damaged bone tissue.

  1. PHBV/PAM scaffolds with local oriented structure through UV polymerization for tissue engineering.

    Science.gov (United States)

    Ke, Yu; Wu, Gang; Wang, Yingjun

    2014-01-01

    Locally oriented tissue engineering scaffolds can provoke cellular orientation and direct cell spread and migration, offering an exciting potential way for the regeneration of the complex tissue. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds with locally oriented hydrophilic polyacrylamide (PAM) inside the macropores of the scaffolds were achieved through UV graft polymerization. The interpenetrating PAM chains enabled good interconnectivity of PHBV/PAM scaffolds that presented a lower porosity and minor diameter of pores than PHBV scaffolds. The pores with diameter below 100  μm increased to 82.15% of PHBV/PAM scaffolds compared with 31.5% of PHBV scaffolds. PHBV/PAM scaffold showed a much higher compressive elastic modulus than PHBV scaffold due to PAM stuffing. At 5 days of culturing, sheep chondrocytes spread along the similar direction in the macropores of PHBV/PAM scaffolds. The locally oriented PAM chains might guide the attachment and spreading of chondrocytes and direct the formation of microfilaments via contact guidance.

  2. Development of novel hybrid poly(l-lactide)/chitosan scaffolds using the rapid freeze prototyping technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, N; Chen, X B [Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan (Canada); Li, M G [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan (Canada); Cooper, D, E-mail: xbc719@mail.usask.ca [Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan (Canada)

    2011-09-15

    Engineered scaffolds have been shown to be critical to various tissue engineering applications. This paper presents the development of a novel three-dimensional scaffold made from a mixture of chitosan microspheres (CMs) and poly(l-lactide) by means of the rapid freeze prototyping (RFP) technique. The CMs were used to encapsulate bovine serum albumin (BSA) and improve the scaffold mechanical properties. Experiments to examine the BSA release were carried out; the BSA release could be controlled by adjusting the crosslink degree of the CMs and prolonged after the CMs were embedded into the PLLA scaffolds, while the examination of the mechanical properties of the scaffolds illustrates that they depend on the ratio of CMs to PLLA in the scaffolds as well as the cryogenic temperature used in the RFP fabrication process. The chemical characteristics of the PLLA/chitosan scaffolds were evaluated by Fourier transform infrared (FTIR) spectroscopy. The morphological and pore structure of the scaffolds were also examined by scanning electron microscopy and micro-tomography. The results obtained show that the scaffolds have higher porosity and enhanced pore size distribution compared to those fabricated by the dispensing-based rapid prototyping technique. This study demonstrates that the novel scaffolds have not only enhanced porous structure and mechanical properties but also showed the potential to preserve the bioactivities of the biomolecules and to control the biomolecule distribution and release rate.

  3. Minding the close relationship.

    Science.gov (United States)

    Harvey, J H; Omarzu, J

    1997-01-01

    In this theoretical analysis, we argue that a process referred to as minding is essential for a couple to feel mutually close and satisfied in a close relationship over a long period Minding represents a package of mutual self-disclosure, other forms of goal-oriented behavior aimed at facilitating the relationship, and attributions about self's and other's motivations, intentions, and Mort in the relationship. Self-disclosure and attribution activities in minding are aimed at getting to know the other, trying to understand the other's motivations and deeper disposition as they pertain to the relationship, and showing respect and acceptance for knowledge gained about other. We link the concept of minding to other major ideas and literatures about how couples achieve closeness: self-disclosure and social penetration, intimacy, empathy and empathic accuracy, and love and self-expansion. We argue that the minding process articulated here has not previously been delineated and that it is a useful composite notion about essential steps in bonding among humans. We also argue that the minding concept stretches our understanding of the interface of attribution and close relationships. We present research possibilities and implications and consider possible alternative positions and counter arguments about the merits of the minding idea for close relationship satisfaction.

  4. Physics of the Mind.

    Science.gov (United States)

    Perlovsky, Leonid I

    2016-01-01

    Is it possible to turn psychology into "hard science"? Physics of the mind follows the fundamental methodology of physics in all areas where physics have been developed. What is common among Newtonian mechanics, statistical physics, quantum physics, thermodynamics, theory of relativity, astrophysics… and a theory of superstrings? The common among all areas of physics is a methodology of physics discussed in the first few lines of the paper. Is physics of the mind possible? Is it possible to describe the mind based on the few first principles as physics does? The mind with its variabilities and uncertainties, the mind from perception and elementary cognition to emotions and abstract ideas, to high cognition. Is it possible to turn psychology and neuroscience into "hard" sciences? The paper discusses established first principles of the mind, their mathematical formulations, and a mathematical model of the mind derived from these first principles, mechanisms of concepts, emotions, instincts, behavior, language, cognition, intuitions, conscious and unconscious, abilities for symbols, functions of the beautiful and musical emotions in cognition and evolution. Some of the theoretical predictions have been experimentally confirmed. This research won national and international awards. In addition to summarizing existing results the paper describes new development theoretical and experimental. The paper discusses unsolved theoretical problems as well as experimental challenges for future research.

  5. PHYSICS OF THE MIND

    Directory of Open Access Journals (Sweden)

    Leonid Perlovsky

    2016-11-01

    Full Text Available Is it possible to turn psychology into hard science? Physics of the mind follows the fundamental methodology of physics in all areas where physics have been developed. What is common among Newtonian mechanics, statistical physics, quantum physics, thermodynamics, theory of relativity, astrophysics... and a theory of superstrings? The common among all areas of physics is a methodology of physics discussed in the first few lines of the paper. Is physics of the mind possible? Is it possible to describe the mind based on the few first principles as physics does? The mind with its variabilities and uncertainties, the mind from perception and elementary cognition to emotions and abstract ideas, to high cognition. Is it possible to turn psychology and neuroscience into hard sciences? The paper discusses established first principles of the mind, their mathematical formulations, and a mathematical model of the mind derived from these first principles, mechanisms of concepts, emotions, instincts, behavior, language, cognition, intuitions, conscious and unconscious, abilities for symbols, functions of the beautiful and musical emotions in cognition and evolution. Some of the theoretical predictions have been experimentally confirmed. This research won national and international awards. In addition to summarizing existing results the paper describes new development theoretical and experimental. The paper discusses unsolved theoretical problems as well as experimental challenges for future research.

  6. Mindfulness in cultural context.

    Science.gov (United States)

    Kirmayer, Laurence J

    2015-08-01

    Mindfulness meditation and other techniques drawn from Buddhism have increasingly been integrated into forms of psychotherapeutic intervention. In much of this work, mindfulness is understood as a mode of awareness that is present-centered and nonevaluative. This form of awareness is assumed to have intrinsic value in promoting positive mental health and adaptation by interrupting discursive thoughts that give rise to suffering. However, in the societies where it originated, mindfulness meditation is part of a larger system of Buddhist belief and practice with strong ethical and moral dimensions. Extracting techniques like mindfulness meditation from the social contexts in which they originate may change the nature and effects of the practice. The papers in this issue of Transcultural Psychiatry explore the implications of a cultural and contextual view of mindfulness for continued dialogue between Buddhist thought and psychiatry. This introductory essay considers the meanings of mindfulness meditation in cultural context and the uses of mindfulness as a therapeutic intervention in contemporary psychiatry and psychology. © The Author(s) 2015.

  7. Mindfulness y creatividad

    OpenAIRE

    Palau Valero, Vicente

    2015-01-01

    Treball Final de Grau en Psicologia. Codi: PS1048. Curs acadèmic 2014-2015 Este trabajo realiza una revisión bibliográfica sobre el efecto que ejerce la práctica del mindfulness sobre el pensamiento creativo. Después de explicar y contextualizar los conceptos de mindfulness y creatividad, se analizarán las variables de tipo afectivo que esperamos afecten a la creatividad influidas por el mindfulness, como son la emoción, bienestar, afecto, personalidad, estrés, ansiedad y atención. Estas v...

  8. Design and characterization of microcapsules-integrated collagen matrixes as multifunctional three-dimensional scaffolds for soft tissue engineering.

    Science.gov (United States)

    Del Mercato, Loretta L; Passione, Laura Gioia; Izzo, Daniela; Rinaldi, Rosaria; Sannino, Alessandro; Gervaso, Francesca

    2016-09-01

    Three-dimensional (3D) porous scaffolds based on collagen are promising candidates for soft tissue engineering applications. The addition of stimuli-responsive carriers (nano- and microparticles) in the current approaches to tissue reconstruction and repair brings about novel challenges in the design and conception of carrier-integrated polymer scaffolds. In this study, a facile method was developed to functionalize 3D collagen porous scaffolds with biodegradable multilayer microcapsules. The effects of the capsule charge as well as the influence of the functionalization methods on the binding efficiency to the scaffolds were studied. It was found that the binding of cationic microcapsules was higher than that of anionic ones, and application of vacuum during scaffolds functionalization significantly hindered the attachment of the microcapsules to the collagen matrix. The physical properties of microcapsules-integrated scaffolds were compared to pristine scaffolds. The modified scaffolds showed swelling ratios, weight losses and mechanical properties similar to those of unmodified scaffolds. Finally, in vitro diffusional tests proved that the collagen scaffolds could stably retain the microcapsules over long incubation time in Tris-HCl buffer at 37°C without undergoing morphological changes, thus confirming their suitability for tissue engineering applications. The obtained results indicate that by tuning the charge of the microcapsules and by varying the fabrication conditions, collagen scaffolds patterned with high or low number of microcapsules can be obtained, and that the microcapsules-integrated scaffolds fully retain their original physical properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Scaffolding as an effort for thinking process optimization on heredity

    Science.gov (United States)

    Azizah, N. R.; Masykuri, M.; Prayitno, B. A.

    2018-04-01

    Thinking is an activity and process of manipulating and transforming data or information into memory. Thinking process is different between one and other person. Thinking process can be developed by interaction between student and their environment, such as scaffolding. Given scaffolding is based on each student necessity. There are 2 level on scaffolding such as explaining, reviewing, and restructuring; and developing conceptual thinking. This research is aimed to describe student’s thinking process on heredity especially on inheritance that is before and after scaffolding. This research used descriptive qualitative method. There were three kinds of subject degree such as the students with high, middle, and low achieving students. The result showed that subjects had some difficulty in dihybrid inheritance question in different place. Most difficulty was on determining the number of different characteristic, parental genotype, gamete, and ratio of genotype and phenotype F2. Based on discussed during scaffolding showed that the subjects have some misunderstanding terms and difficulty to determine parental, gamete, genotype, and phenotype. Final result in this research showed that the subjects develop thinking process higher after scaffolding. Therefore the subjects can solve question properly.

  10. Mechanoactive scaffold induces tendon remodeling and expression of fibrocartilage markers.

    Science.gov (United States)

    Spalazzi, Jeffrey P; Vyner, Moira C; Jacobs, Matthew T; Moffat, Kristen L; Lu, Helen H

    2008-08-01

    Biological fixation of soft tissue-based grafts for anterior cruciate ligament (ACL) reconstruction poses a major clinical challenge. The ACL integrates with subchondral bone through a fibrocartilage enthesis, which serves to minimize stress concentrations and enables load transfer between two distinct tissue types. Functional integration thus requires the reestablishment of this fibrocartilage interface on reconstructed ACL grafts. We designed and characterized a novel mechanoactive scaffold based on a composite of poly-alpha-hydroxyester nanofibers and sintered microspheres; we then used the scaffold to test the hypothesis that scaffold-induced compression of tendon grafts would result in matrix remodeling and the expression of fibrocartilage interface-related markers. Histology coupled with confocal microscopy and biochemical assays were used to evaluate the effects of scaffold-induced compression on tendon matrix collagen distribution, cellularity, proteoglycan content, and gene expression over a 2-week period. Scaffold contraction resulted in over 15% compression of the patellar tendon graft and upregulated the expression of fibrocartilage-related markers such as Type II collagen, aggrecan, and transforming growth factor-beta3 (TGF-beta3). Additionally, proteoglycan content was higher in the compressed tendon group after 1 day. The data suggest the potential of a mechanoactive scaffold to promote the formation of an anatomic fibrocartilage enthesis on tendon-based ACL reconstruction grafts.

  11. Indirect three-dimensional printing of synthetic polymer scaffold based on thermal molding process

    International Nuclear Information System (INIS)

    Park, Jeong Hun; Jung, Jin Woo; Cho, Dong-Woo; Kang, Hyun-Wook

    2014-01-01

    One of the major issues in tissue engineering has been the development of three-dimensional (3D) scaffolds, which serve as a structural template for cell growth and extracellular matrix formation. In scaffold-based tissue engineering, 3D printing (3DP) technology has been successfully applied for the fabrication of complex 3D scaffolds by using both direct and indirect techniques. In principle, direct 3DP techniques rely on the straightforward utilization of the final scaffold materials during the actual scaffold fabrication process. In contrast, indirect 3DP techniques use a negative mold based on a scaffold design, to which the desired biomaterial is cast and then sacrificed to obtain the final scaffold. Such indirect 3DP techniques generally impose a solvent-based process for scaffold fabrication, resulting in a considerable increase in the fabrication time and poor mechanical properties. In addition, the internal architecture of the resulting scaffold is affected by the properties of the biomaterial solution. In this study, we propose an advanced indirect 3DP technique using projection-based micro-stereolithography and an injection molding system (IMS) in order to address these challenges. The scaffold was fabricated by a thermal molding process using IMS to overcome the limitation of the solvent-based molding process in indirect 3DP techniques. The results indicate that the thermal molding process using an IMS has achieved a substantial reduction in scaffold fabrication time and has also provided the scaffold with higher mechanical modulus and strength. In addition, cell adhesion and proliferation studies have indicated no significant difference in cell activity between the scaffolds prepared by solvent-based and thermal molding processes. (paper)

  12. Electrospun gelatin/poly(ε-caprolactone) fibrous scaffold modified with calcium phosphate for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Rajzer, Izabella, E-mail: irajzer@ath.bielsko.pl [University of Bielsko-Biala (ATH), Department of Mechanical Engineering Fundamentals, Division of Materials Engineering, Willowa 2 Street, 43-309 Bielsko-Biała (Poland); Menaszek, Elżbieta [Jagiellonian University (UJ), Collegium Medicum, Department of Cytobiology, Medyczna 9 Street, 30-068 Cracow (Poland); Kwiatkowski, Ryszard [University of Bielsko-Biala (ATH), Faculty of Materials and Environmental Sciences, Institute of Textile Engineering and Polymer Materials, Willowa 2 Street, 43-309 Bielsko-Biała (Poland); Planell, Josep A.; Castano, Oscar [Institute for Bioengineering of Catalonia (IBEC), Biomaterials for Regenerative Therapies, Baldiri Reixac 15-21, 08028 Barcelona (Spain); Polytechnic University of Catalonia (UPC), Diagonal 647, 08028 Barcelona (Spain); CIBER-BBN The Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine, Barcelona (Spain)

    2014-11-01

    In this study gelatin (Gel) modified with calcium phosphate nanoparticles (SG5) and polycaprolactone (PCL) were used to prepare a 3D bi-layer scaffold by collecting electrospun PCL and gelatin/SG5 fibers separately in the same collector. The objective of this study was to combine the desired properties of PCL and Gel/SG5 in the same scaffold in order to enhance mineralization, thus improving the ability of the scaffold to bond to the bone tissue. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and the wide angle X-ray diffraction (WAXD) measurements confirmed that SG5 nanoparticles were successfully incorporated into the fibrous gelatin matrix. The composite Gel/SG5/PCL scaffold exhibited more enhanced mechanical properties than individual Gel and Gel/SG5 scaffolds. The presence of SG5 nanoparticles accelerated the nucleation and growth of apatite crystals on the surface of the composite Gel/SG5/PCL scaffold in simulated body fluid (SBF). The osteoblast response in vitro to developed electrospun scaffolds (PCL and Gel/SG5/PCL) was investigated by using normal human primary NHOst cell lines. NHOst cell culture studies showed that higher alkaline phosphatase (ALP) activity and better mineralization were obtained in the case of composite materials than in pure PCL scaffolds. The mechanically strong PCL scaffold served as a skeleton, while the Gel/SG5 fibers facilitated cell spreading and mineralization of the scaffold. - Highlights: • Bi-layer scaffolds were produced by electrospinning method. • The addition of nanoparticles enhanced the bioactivity of scaffold. • Bi-layer scaffold enhanced ALP activity and NHOst cell mineralization.

  13. PLDLA/PCL-T Scaffold for Meniscus Tissue Engineering.

    Science.gov (United States)

    Esposito, Andrea Rodrigues; Moda, Marlon; Cattani, Silvia Mara de Melo; de Santana, Gracy Mara; Barbieri, Juliana Abreu; Munhoz, Monique Moron; Cardoso, Túlio Pereira; Barbo, Maria Lourdes Peris; Russo, Teresa; D'Amora, Ugo; Gloria, Antonio; Ambrosio, Luigi; Duek, Eliana Aparecida de Rezende

    2013-04-01

    The inability of the avascular region of the meniscus to regenerate has led to the use of tissue engineering to treat meniscal injuries. The aim of this study was to evaluate the ability of fibrochondrocytes preseeded on PLDLA/PCL-T [poly(L-co-D,L-lactic acid)/poly(caprolactone-triol)] scaffolds to stimulate regeneration of the whole meniscus. Porous PLDLA/PCL-T (90/10) scaffolds were obtained by solvent casting and particulate leaching. Compressive modulus of 9.5±1.0 MPa and maximum stress of 4.7±0.9 MPa were evaluated. Fibrochondrocytes from rabbit menisci were isolated, seeded directly on the scaffolds, and cultured for 21 days. New Zealand rabbits underwent total meniscectomy, after which implants consisting of cell-free scaffolds or cell-seeded scaffolds were introduced into the medial knee meniscus; the negative control group consisted of rabbits that received no implant. Macroscopic and histological evaluations of the neomeniscus were performed 12 and 24 weeks after implantation. The polymer scaffold implants adapted well to surrounding tissues, without apparent rejection, infection, or chronic inflammatory response. Fibrocartilaginous tissue with mature collagen fibers was observed predominantly in implants with seeded scaffolds compared to cell-free implants after 24 weeks. Similar results were not observed in the control group. Articular cartilage was preserved in the polymeric implants and showed higher chondrocyte cell number than the control group. These findings show that the PLDLA/PCL-T 90/10 scaffold has potential for orthopedic applications since this material allowed the formation of fibrocartilaginous tissue, a structure of crucial importance for repairing injuries to joints, including replacement of the meniscus and the protection of articular cartilage from degeneration.

  14. Using Scaffolds in Problem-Based Hypermedia

    Science.gov (United States)

    Su, Yuyan; Klein, James D.

    2010-01-01

    This study investigated the use of scaffolds in problem-based hypermedia. Three hundred and twelve undergraduate students enrolled in a computer literacy course worked in project teams to use a hypermedia PBL program focused on designing a personal computer. The PBL program included content scaffolds, metacognitive scaffolds, or no scaffolds.…

  15. Rheological, biocompatibility and osteogenesis assessment of fish collagen scaffold for bone tissue engineering.

    Science.gov (United States)

    Elango, Jeevithan; Zhang, Jingyi; Bao, Bin; Palaniyandi, Krishnamoorthy; Wang, Shujun; Wenhui, Wu; Robinson, Jeya Shakila

    2016-10-01

    In the present investigation, an attempt was made to find an alternative to mammalian collagen with better osteogenesis ability. Three types of collagen scaffolds - collagen, collagen-chitosan (CCH), and collagen-hydroxyapatite (CHA) - were prepared from the cartilage of Blue shark and investigated for their physico-functional and mechanical properties in relation to biocompatibility and osteogenesis. CCH scaffold was superior with pH 4.5-4.9 and viscosity 9.7-10.9cP. Notably, addition of chitosan and HA (hydroxyapatite) improved the stiffness (11-23MPa) and degradation rate but lowered the water binding capacity and porosity of the scaffold. Interestingly, CCH scaffolds remained for 3days before complete in-vitro biodegradation. The decreased amount of viable T-cells and higher level of FAS/APO-1 were substantiated the biocompatibility properties of prepared collagen scaffolds. Osteogenesis study revealed that the addition of CH and HA in both fish and mammalian collagen scaffolds could efficiently promote osteoblast cell formation. The ALP activity was significantly high in CHA scaffold-treated osteoblast cells, which suggests an enhanced bone-healing process. Therefore, the present study concludes that the composite scaffolds prepared from fish collagen with higher stiffness, lower biodegradation rate, better biocompatible, and osteogenesis properties were suitable biomaterial for a bone tissue engineering application as an alternative to mammalian collagen scaffolds. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A novel surface modification on calcium polyphosphate scaffold for articular cartilage tissue engineering

    International Nuclear Information System (INIS)

    Lien, S.-M.; Liu, C.-K.; Huang, T.-J.

    2007-01-01

    The surface of porous three-dimensional (3D) calcium polyphosphate (CPP) scaffold was modified by treatment of quenching-after-sintering in the fabrication process. Scanning electron microscopic examination and degradation tests confirmed a new type of surface modification. A rotary-shaking culture was compared to that of a stationary culture and the results showed that rotary shaking led to enhanced extracellular matrices (ECM) secretion of both proteoglycans and collagen. Rotary-shaking cultured results showed that the quenching-treated CPP scaffold produced a better cartilage tissue, with both proteoglycans and collagen secretions enhanced, than the air-cooled-after-sintering scaffolds. Moreover, β-CPP scaffolds were better for the ECM secretion of both proteoglycans and collagen than the β-CPP + γ-CPP multiphase scaffold. However, the multiphase scaffold led to higher growth rate than that of β-CPP scaffold; the quenching-after-sintering treatment reversed this. In addition, the ECM secretions of both proteoglycans and collagen in the quenching-treated β-CPP scaffold were higher than those in the air-cooled one. Thus, the novel treatment of quenching-after-sintering has shown merits to the porous 3D CPP scaffolds for articular cartilage tissue engineering

  17. Fabrication of highly porous biodegradable biomimetic nanocomposite as advanced bone tissue scaffold

    Directory of Open Access Journals (Sweden)

    Abdalla Abdal-hay

    2017-02-01

    Full Text Available Development of bioinspired or biomimetic materials is currently a challenge in the field of tissue regeneration. In-situ 3D biomimetic microporous nanocomposite scaffold has been developed using a simple lyophilization post hydrothermal reaction for bone healing applications. The fabricated 3D porous scaffold possesses advantages of good bonelike apatite particles distribution, thermal properties and high porous interconnected network structure. High dispersion bonelike apatite nanoparticles (NPs rapidly nucleated and deposited from surrounding biological minerals within chitosan (CTS matrices using hydrothermal technique. After that, freeze-drying method was applied on the composite solution to form the desired porous 3D architecture. Interestingly, the porosity and pore size of composite scaffold were not significantly affected by the particles size and particles content within the CTS matrix. Our results demonstrated that the compression modulus of porous composite scaffold is twice higher than that of plain CTS scaffold, indicating a maximization of the chemical interaction between polymer matrix and apatite NPs. Cytocompatibility test for MC3T3-E1 pre-osteoblasts cell line using MTT-indirect assay test showed that the fabricated 3D microporous nanocomposite scaffold possesses higher cell proliferation and growth than that of pure CTS scaffold. Collectively, our results suggest that the newly developed highly porous apatite/CTS nanocomposite scaffold as an alternative of hydroxyapatite/CTS scaffold may serve as an excellent porous 3D platform for bone tissue regeneration.

  18. Mind, brain and person:

    African Journals Online (AJOL)

    Adele

    Keywords: Philosophy; Models/Theories of Psychiatry; dualism; monism; pluralism. Received: 26.05. ... in terms of the logical and computational processes involved and are ..... Wallace E. Mind-body: monistic dual aspect interactionism. J Nerv.

  19. Origins of Mindfulness & Meditation

    DEFF Research Database (Denmark)

    Singla, Rashmi

    2011-01-01

    Mindfulness & meditation are gaining popularity in the Western psychological practice in the past 3-4 decades, especially within psychotherapeutic approaches, health promotion, and stress reduction. The origins and the broader context, however, seem to be overlooked in some of these practices......- mind, centrality of consciousness and meditation as a part of daily conduct are presented. The basic constructs of Buddhism, an integral part of Indian psychology, in relation to mindfulness and meditation, are also delineated as illustrations of these assumptions. The second part reflects...... on the application of the meditative practices through cognitive existential study of mindfulness (Kabat-Zinn, 2003) and a study on the phenomenology of meditation (Madsen, 2007). Both emphasise an experienced instructor, regular practice as a part of daily life, conceptual consciousness understandings...

  20. Mind Over Matter: Methamphetamine

    Science.gov (United States)

    ... Teaching Guide and Series / Methamphetamine Mind Over Matter: Methamphetamine (Meth) Print Order Free Publication in: English Spanish ... paranoia, aggressiveness, and hallucinations. The Brain's Response to Methamphetamine Hi, my name's Sara Bellum. Welcome to my ...

  1. Mind a brief introduction

    CERN Document Server

    Searle, John R

    2004-01-01

    "The philosophy of mind is unique among contemporary philosophical subjects," writes John Searle, "in that all of the most famous and influential theories are false." One of the world's most eminent thinkers, Searle dismantles these theories as he presents a vividly written, comprehensive introduction to the mind. He begins with a look at the twelve problems of philosophy of mind--which he calls "Descartes and Other Disasters"--problems which he returns to throughout the volume, as he illuminates such topics as materialism, consciousness, the mind-body problem, intentionality, mental causation, free will, and the self. The book offers a refreshingly direct and engaging introduction to one of the most intriguing areas of philosophy.

  2. Ornamenting 3D printed scaffolds with cell-laid extracellular matrix for bone tissue regeneration.

    Science.gov (United States)

    Pati, Falguni; Song, Tae-Ha; Rijal, Girdhari; Jang, Jinah; Kim, Sung Won; Cho, Dong-Woo

    2015-01-01

    3D printing technique is the most sophisticated technique to produce scaffolds with tailorable physical properties. But, these scaffolds often suffer from limited biological functionality as they are typically made from synthetic materials. Cell-laid mineralized ECM was shown to be potential for improving the cellular responses and drive osteogenesis of stem cells. Here, we intend to improve the biological functionality of 3D-printed synthetic scaffolds by ornamenting them with cell-laid mineralized extracellular matrix (ECM) that mimics a bony microenvironment. We developed bone graft substitutes by using 3D printed scaffolds made from a composite of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) and mineralized ECM laid by human nasal inferior turbinate tissue-derived mesenchymal stromal cells (hTMSCs). A rotary flask bioreactor was used to culture hTMSCs on the scaffolds to foster formation of mineralized ECM. A freeze/thaw cycle in hypotonic buffer was used to efficiently decellularize (97% DNA reduction) the ECM-ornamented scaffolds while preserving its main organic and inorganic components. The ECM-ornamented 3D printed scaffolds supported osteoblastic differentiation of newly-seeded hTMSCs by upregulating four typical osteoblastic genes (4-fold higher RUNX2; 3-fold higher ALP; 4-fold higher osteocalcin; and 4-fold higher osteopontin) and increasing calcium deposition compared to bare 3D printed scaffolds. In vivo, in ectopic and orthotopic models in rats, ECM-ornamented scaffolds induced greater bone formation than that of bare scaffolds. These results suggest a valuable method to produce ECM-ornamented 3D printed scaffolds as off-the-shelf bone graft substitutes that combine tunable physical properties with physiological presentation of biological signals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Mind, Evolution, and Computers

    OpenAIRE

    Abrahamson, Joseph R.

    1994-01-01

    Science deals with knowledge of the material world based on objective reality. It is under constant attack by those who need magic, that is, concepts based on imagination and desire, with no basis in objective reality. A convenient target for such people is speculation on the machinery and method of operation of the human mind, questions that are still obscure in 1994. In The Emperor's New Mind, Roger Penrose attempts to look beyond objective reality for possible answers, using, in his argume...

  4. Theory of Mind

    OpenAIRE

    Jovanka, Della Raymena; Setiawan, Denny

    2013-01-01

    This paper aimed to describe preschool age children's Theory of Mind, as a part of their cognitive development. Some factors that affect the children's Theory of Mind are parental talking, social economic background, parents' education, etc.The research participants are 82 preschool age children in South Jakarta, Indonesia. The method used in this paper was quasi experiment, adaptated from Sobel, Li, and Corriveau's method. The statistical data were examined by one way ANOVA. These data sugge...

  5. Mind full of life: Does mindfulness confer resilience to suicide by increasing zest for life?

    Science.gov (United States)

    Collins, Khan R L; Stritzke, Werner G K; Page, Andrew C; Brown, Julia D; Wylde, Tricia J

    2018-01-15

    Mindfulness is a trainable skill that may enhance resilience to suicidality among vulnerable groups such as young people. The current study examined whether mindfulness protects against suicidal desire in the face of heightened risk and adversity by increasing zest for life in a sample of university students. In a prospective design, participants (N = 233) were assessed at two time points over eight weeks. Online surveys included the Mindful Attention and Awareness Scale, Zest for Life Scale, Interpersonal Needs Questionnaire, Kessler Psychological Distress Scale, and items assessing suicidal ideation and suicidal intent. Baseline mindfulness was associated with lower suicidal ideation and intent at follow-up. Moderated mediation analyses confirmed the effects of mindfulness on ideation and intent were mediated by zest for life and these indirect effects were stronger at higher versus lower levels of general (psychological distress) and suicide-specific (perceived burdensomeness and thwarted belongingness) risk. Single item assessments of suicidal desire. Findings suggest that mindfulness protects against suicidal desire in conditions of heightened risk and adversity by enhancing one's orientation towards a life worth living. Theories of suicide should consider the dynamic interplay between risk and life-sustaining resilience, while clinicians treating suicidality could use mindfulness strategies to strengthen the desire to (re)engage with life, thereby complementing direct amelioration of suicide risk factors. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Mindfulness in Salah Prayer and its Association with Mental Health.

    Science.gov (United States)

    Ijaz, Shahid; Khalily, Muhammad Tahir; Ahmad, Irshad

    2017-12-01

    Plethora of researches has been carried out for the last many decades and has identified relationship between mental health and religious convictions; in particular, range of religious practices has been found instrumental in the promotion of mental health. The aim of this paper is to find out association between mindfulness in Salah (prayer) and mental health of individuals who identify themselves with Islam and to examine the mental health of those Muslims who offer Salah prayer with mindfulness and those who offer without mindfulness. A total of 174 participants with mean age of 21.57 including 62% males and females 38% were selected through convenient sampling. RAND Mental Health Inventory was used to measure mental health and other three variables; three self-reported measures were constructed. They included Islamic religious education scale, Salah education scale and mindfulness in Salah scale. Psychometric properties for all scales were established. The findings indicated that mean on mindfulness and mental health was significantly higher for those who were offering Salah (prayer) regularly (p prayer) with mindfulness had also significantly higher mean for mental health (p prayer regularly and with mindfulness have better mental health as compared with those who don't offer it regularly and with mindfulness. The findings of this study urge to spread awareness regarding offering prayer regularly with mindfulness for the better outcome of mental health in people.

  7. Comparison between PCL/hydroxyapatite (HA) and PCL/halloysite nanotube (HNT) composite scaffolds prepared by co-extrusion and gas foaming.

    Science.gov (United States)

    Jing, Xin; Mi, Hao-Yang; Turng, Lih-Sheng

    2017-03-01

    In this work, three-dimensional poly(caprolactone) (PCL) tissue engineering scaffolds were prepared by co-extrusion and gas foaming. Biocompatible hydroxyapatite (HA) and halloysite nanotubes (HNT) were added to the polymer matrix to enhance the mechanical properties and bioactivity of the composite scaffolds. The effects of HA and HNT on the rheological behavior, microstructure, and mechanical properties of the composite scaffolds were systematically compared. It was found that the HNT improved viscosity more significantly than HA, and reduced the pore size of scaffolds, while the mechanical performance of PCL/HNT scaffolds was higher than PCL/HA scaffolds with the same filler content. Human mesenchymal stem cells (hMSCs) were used as the cell model to compare the biological properties of two composite scaffolds. The results demonstrated that cells could survive on all scaffolds, and showed a more flourishing living state on the composite scaffolds. The cell differentiation for 5% HA and 1% HNT scaffolds were significantly higher than other scaffolds, while the differentiation of 5% HNT scaffolds was lower than that of 1% HNT scaffolds mainly because of the reduced pore size and pore interconnectivity. Therefore, this study suggested that, with proper filler content and control of microstructure through processing, HNT could be a suitable substitute for HA for bone tissue engineering to reduce the cost and improve mechanical performance. Copyright © 2016. Published by Elsevier B.V.

  8. Annealing free, clean graphene transfer using alternative polymer scaffolds.

    Science.gov (United States)

    Wood, Joshua D; Doidge, Gregory P; Carrion, Enrique A; Koepke, Justin C; Kaitz, Joshua A; Datye, Isha; Behnam, Ashkan; Hewaparakrama, Jayan; Aruin, Basil; Chen, Yaofeng; Dong, Hefei; Haasch, Richard T; Lyding, Joseph W; Pop, Eric

    2015-02-06

    We examine the transfer of graphene grown by chemical vapor deposition (CVD) with polymer scaffolds of poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA), poly(phthalaldehyde) (PPA), and poly(bisphenol A carbonate) (PC). We find that optimally reactive PC scaffolds provide the cleanest graphene transfers without any annealing, after extensive comparison with optical microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, and scanning tunneling microscopy. Comparatively, films transferred with PLA, PPA, PMMA/PC, and PMMA have a two-fold higher roughness and a five-fold higher chemical doping. Using PC scaffolds, we demonstrate the clean transfer of CVD multilayer graphene, fluorinated graphene, and hexagonal boron nitride. Our annealing free, PC transfers enable the use of atomically-clean nanomaterials in biomolecule encapsulation and flexible electronic applications.

  9. Annealing free, clean graphene transfer using alternative polymer scaffolds

    International Nuclear Information System (INIS)

    Wood, Joshua D; Doidge, Gregory P; Carrion, Enrique A; Koepke, Justin C; Datye, Isha; Behnam, Ashkan; Hewaparakrama, Jayan; Aruin, Basil; Chen, Yaofeng; Lyding, Joseph W; Kaitz, Joshua A; Dong, Hefei; Haasch, Richard T; Pop, Eric

    2015-01-01

    We examine the transfer of graphene grown by chemical vapor deposition (CVD) with polymer scaffolds of poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA), poly(phthalaldehyde) (PPA), and poly(bisphenol A carbonate) (PC). We find that optimally reactive PC scaffolds provide the cleanest graphene transfers without any annealing, after extensive comparison with optical microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, and scanning tunneling microscopy. Comparatively, films transferred with PLA, PPA, PMMA/PC, and PMMA have a two-fold higher roughness and a five-fold higher chemical doping. Using PC scaffolds, we demonstrate the clean transfer of CVD multilayer graphene, fluorinated graphene, and hexagonal boron nitride. Our annealing free, PC transfers enable the use of atomically-clean nanomaterials in biomolecule encapsulation and flexible electronic applications. (paper)

  10. Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering

    International Nuclear Information System (INIS)

    Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K.; Potdar, Pravin D.; Mishra, Narayan C.

    2014-01-01

    In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2–1.5 wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. - Highlights: • PCL/gelatin/collagen type I scaffold was fabricated for skin tissue engineering. • PCL/gelatin/collagen type I scaffold showed higher fibroblast growth than PCL/gelatin one. • PCL/gelatin/collagen type I might be one of the ideal scaffold for

  11. Mindfulness Meditation-Based Pain Relief Employs Different Neural Mechanisms Than Placebo and Sham Mindfulness Meditation-Induced Analgesia

    Science.gov (United States)

    Emerson, Nichole M.; Farris, Suzan R.; Ray, Jenna N.; Jung, Youngkyoo; McHaffie, John G.; Coghill, Robert C.

    2015-01-01

    modulation. SIGNIFICANCE STATEMENT Recent findings have demonstrated that mindfulness meditation significantly reduces pain. Given that the “gold standard” for evaluating the efficacy of behavioral interventions is based on appropriate placebo comparisons, it is imperative that we establish whether there is an effect supporting meditation-related pain relief above and beyond the effects of placebo. Here, we provide novel evidence demonstrating that mindfulness meditation produces greater pain relief and employs distinct neural mechanisms than placebo cream and sham mindfulness meditation. Specifically, mindfulness meditation-induced pain relief activated higher-order brain regions, including the orbitofrontal and cingulate cortices. In contrast, placebo analgesia was associated with decreased pain-related brain activation. These findings demonstrate that mindfulness meditation reduces pain through unique mechanisms and may foster greater acceptance of meditation as an adjunct pain therapy. PMID:26586819

  12. Human-like collagen/nano-hydroxyapatite scaffolds for the culture of chondrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Liping; Duan, Zhiguang [Shaanxi Key Laboratory of Degradable Biomedical Materials, Northwest University, 229 Taibai North Road, Xi' an, Shaanxi 710069 (China); Shaanxi R and D Center of Biomaterials and Fermentation Engineering, Northwest University, 229 Taibai North Road, Xi' an, Shaanxi 710069 (China); Fan, Daidi, E-mail: fandaidi@nwu.edu.cn [Shaanxi Key Laboratory of Degradable Biomedical Materials, Northwest University, 229 Taibai North Road, Xi' an, Shaanxi 710069 (China); Shaanxi R and D Center of Biomaterials and Fermentation Engineering, Northwest University, 229 Taibai North Road, Xi' an, Shaanxi 710069 (China); Mi, Yu; Hui, Junfeng [Shaanxi Key Laboratory of Degradable Biomedical Materials, Northwest University, 229 Taibai North Road, Xi' an, Shaanxi 710069 (China); Shaanxi R and D Center of Biomaterials and Fermentation Engineering, Northwest University, 229 Taibai North Road, Xi' an, Shaanxi 710069 (China); Chang, Le [School of Chemical Engineering, Northwest University, Xi' an, Shaanxi 710069 (China)

    2013-03-01

    Three dimensional (3D) biodegradable porous scaffolds play a key role in cartilage tissue repair. Freeze-drying and cross-linking techniques were used to fabricate a 3D composite scaffold that combined the excellent biological characteristics of human-like collagen (HLC) and the outstanding mechanical properties of nano-hydroxyapatite (nHA). The scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and compression tests, using Relive Registered-Sign Artificial Bone (RAB) scaffolds as a control. HLC/nHA scaffolds displayed homogeneous interconnected macroporous structure and could withstand a compression stress of 2.67 {+-} 0.37 MPa, which was higher than that of the control group. Rabbit chondrocytes were seeded on the composite porous scaffolds and cultured for 21 days. Cell/scaffold constructs were examined using SEM, histological procedures, and biochemical assays for cell proliferation and the production of glycosaminoglycans (GAGs). The results indicated that HLC/nHA porous scaffolds were capable of encouraging cell adhesion, homogeneous distribution and abundant GAG synthesis, and maintaining natural chondrocyte morphology compared to RAB scaffolds. In conclusion, the presented data warrants the further exploration of HLC/nHA scaffolds as a potential biomimetic platform for chondrocytes in cartilage tissue engineering. - Highlights: Black-Right-Pointing-Pointer Human-like collagen was first used to prepare cartilage tissue engineering scaffold. Black-Right-Pointing-Pointer Genipin, a natural biological cross-linking agent, was introduced to treat scaffold. Black-Right-Pointing-Pointer We chose market product as a control.

  13. PEDOT:PSS-Containing Nanohydroxyapatite/Chitosan Conductive Bionanocomposite Scaffold: Fabrication and Evaluation

    Directory of Open Access Journals (Sweden)

    Alireza Lari

    2016-01-01

    Full Text Available Conductive poly(3,4-ethylenedioxythiophene-poly(4-styrene sulfonate (PEDOT:PSS was incorporated into nanohydroxyapatite/chitosan (nHA/CS composite scaffolds through a freezing and lyophilization technique. The bionanocomposite conductive scaffold was then characterized using several techniques. A scanning electron microscope image showed that the nHA and PEDOT:PSS were dispersed homogeneously in the chitosan matrix, which was also confirmed by energy-dispersive X-ray (EDX analysis. The conductive properties were measured using a digital multimeter. The weight loss and water-uptake properties of the bionanocomposite scaffolds were studied in vitro. An in vitro cell cytotoxicity test was carried out using mouse fibroblast (L929 cells cultured onto the scaffolds. Using a freezing and lyophilization technique, it was possible to fabricate three-dimensional, highly porous, and interconnected PEDOT:PSS/nHA/CS scaffolds with good handling properties. The porosity was 74% and the scaffold’s conductivity was 9.72±0.78 μS. The surface roughness was increased with the incorporation of nHA and PEDOT:PSS into the CS scaffold. The compressive mechanical properties increased significantly with the incorporation of nHA but did not change significantly with the incorporation of PEDOT:PSS. The PEDOT:PSS-containing nHA/CS scaffold exhibited significantly higher cell attachment. The PEDOT:PSS/nHA/CS scaffold could be a potential bionanocomposite conductive scaffold for tissue engineering.

  14. Morphological Effects of HA on the Cell Compatibility of Electrospun HA/PLGA Composite Nanofiber Scaffolds

    Directory of Open Access Journals (Sweden)

    Adnan Haider

    2014-01-01

    Full Text Available Tissue engineering is faced with an uphill challenge to design a platform with appropriate topography and suitable surface chemistry, which could encourage desired cellular activities and guide bone tissue regeneration. To develop such scaffolds, composite nanofiber scaffolds of nHA and sHA with PLGA were fabricated using electrospinning technique. nHA was synthesized using precipitation method, whereas sHA was purchased. The nHA and sHA were suspended in PLGA solution separately and electrospun at optimized electrospinning parameters. The composite nanofiber scaffolds were characterized by FE-SEM, EDX analysis, TEM, XRD analysis, FTIR, and X-ray photoelectron. The potential of the HA/PLGA composite nanofiber as bone scaffolds in terms of their bioactivity and biocompatibility was assessed by culturing the osteoblastic cells onto the composite nanofiber scaffolds. The results from in vitro studies revealed that the nHA/PLGA composite nanofiber scaffolds showed higher cellular adhesion, proliferation, and enhanced osteogenesis performance, along with increased Ca+2 ions release compared to the sHA/PLGA composite nanofiber scaffolds and pristine PLGA nanofiber scaffold. The results show that the structural dependent property of HA might affect its potential as bone scaffold and implantable materials in regenerative medicine and clinical tissue engineering.

  15. A comparison of scaffold-free and scaffold-based reconstructed human skin models as alternatives to animal use.

    Science.gov (United States)

    Kinikoglu, Beste

    2017-12-01

    Tissue engineered full-thickness human skin substitutes have various applications in the clinic and in the laboratory, such as in the treatment of burns or deep skin defects, and as reconstructed human skin models in the safety testing of drugs and cosmetics and in the fundamental study of skin biology and pathology. So far, different approaches have been proposed for the generation of reconstructed skin, each with its own advantages and disadvantages. Here, the classic tissue engineering approach, based on cell-seeded polymeric scaffolds, is compared with the less-studied cell self-assembly approach, where the cells are coaxed to synthesise their own extracellular matrix (ECM). The resulting full-thickness human skin substitutes were analysed by means of histological and immunohistochemical analyses. It was found that both the scaffold-free and the scaffold-based skin equivalents successfully mimicked the functionality and morphology of native skin, with complete epidermal differentiation (as determined by the expression of filaggrin), the presence of a continuous basement membrane expressing collagen VII, and new ECM deposition by dermal fibroblasts. On the other hand, the scaffold-free model had a thicker epidermis and a significantly higher number of Ki67-positive proliferative cells, indicating a higher capacity for self-renewal, as compared to the scaffold-based model. 2017 FRAME.

  16. [Mindful neuropsychology: Mindfulness-based cognitive remediation].

    Science.gov (United States)

    Bulzacka, E; Lavault, S; Pelissolo, A; Bagnis Isnard, C

    2018-02-01

    Mindfulness based interventions (MBI) have recently gained much interest in western medicine. MBSR paradigm is based on teaching participants to pay complete attention to the present experience and act nonjudgmentally towards stressful events. During this mental practice the meditator focuses his or her attention on the sensations of the body. While the distractions (mental images, thoughts, emotional or somatic states) arise the participant is taught to acknowledge discursive thoughts and cultivate the state of awareness without immediate reaction. The effectiveness of these programs is well documented in the field of emotional response regulation in depression (relapse prevention), anxiety disorders, obsessive-compulsive disorder or eating disorders. Furthermore, converging lines of evidence support the hypothesis that mindfulness practice improves cognition, especially the ability to sustain attention and think in a more flexible manner. Nevertheless, formal rehabilitation programs targeting cognitive disturbances resulting from psychiatric (depression, disorder bipolar, schizophrenia) or neurologic conditions (brain injury, dementia) seldom rely on MBI principles. This review of literature aims at discussing possible links between MBI and clinical neuropsychology. We conducted a review of literature using electronic databases up to December 2016, screening studies with variants of the keywords ("Mindfulness", "MBI", "MBSR", "Meditation") OR/AND ("Cognition", "Attention", "Executive function", "Memory", "Learning") RESULTS: In the first part, we describe key concepts of the neuropsychology of attention in the light of Posner's model of attention control. We also underline the potential scope of different therapeutic contexts where disturbances of attention may be clinically relevant. Second, we review the efficacy of MBI in the field of cognition (thinking disturbances, attention biases, memory and executive processes impairment or low metacognitive abilities

  17. Mindfulness for unge

    DEFF Research Database (Denmark)

    Nielsen, Anne Maj

    Undersøgelsen af, hvordan interventionsforløbet Mindfulness for unge virkede, er baseret på kvalitative interview med 24 elever i 9. klasse, som har deltaget i Mindfulness for unge i 8 uger. Resultater: Det fælles mindfulnessforløb i klassen har lært mange af eleverne at kunne bruge deres bevidste...... opmærksomhed til at forholde sig til deres situation, tilstand og muligheder, så de udvikler deres ressourcer i stedet for at blive fanget i afmagt og stress. Det er oplevelser og erfaringer med de praktiske mindfulness-øvelser, der har været særlig betydningsfuldt. Overordnet ser Mindfulness for unge ud til...... at kunne bidrage til at forebygge stress i skolen for en del elever, når mindfulness-instruktørens undervisning følges op og faciliteres af en mindfulnesspraktiserende lærer, der kender klassen og eleverne godt. Interesse og opbakning fra skolens ledelse og elevernes familier er også væsentligt...

  18. Dispositional Mindfulness Moderates the Effects of Stress among Adolescents: Rumination as a Mediator

    Science.gov (United States)

    Ciesla, Jeffrey A.; Reilly, Laura C.; Dickson, Kelsey S.; Emanuel, Amber S.; Updegraff, John A.

    2012-01-01

    Recent research has demonstrated that higher levels of mindfulness are associated with greater psychological and physical health. However, the majority of this research has been conducted with adults; research is only beginning to examine the effects of mindfulness among adolescents. Further, research into adolescent mindfulness has typically…

  19. Scaffolding in Assisted Instruction

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available On-The-Job Training, developed as direct instruction, is one of the earliest forms of training. This method is still widely in use today because it requires only a person who knows how to do the task, and the tools the person uses to do the task. This paper is intended to be a study of the methods used in education in Knowledge Society, with more specific aspects in training the trainers; as a result of this approach, it promotes scaffolding in assisted instruction as a reflection of the digital age for the learning process. Training the trainers in old environment with default techniques and designing the learning process in assisted instruction, as an application of the Vygotskian concept of the zone of proximal development (ZPD to the area of computer literacy for the younger users, generate diversity in educational communities and requires standards for technology infrastructure, standards for the content, developed as a concepts map, and applications for personalized in-struction, based on ZPD theory.

  20. Citation patterns and trends of systematic reviews about mindfulness.

    Science.gov (United States)

    Chiesa, Alberto; Fazia, Teresa; Bernardinelli, Luisa; Morandi, Gabriella

    2017-08-01

    We performed a citation analysis of the literature about mindfulness aimed at describing the most significant topics and the impact of more relevant papers. We classified 128 systematic reviews about mindfulness-based intervention retrieved in Scopus according to their object, the population included and the type of mindfulness proposed. The citation counting was reported. The cumulative citation numbers per chronological years and article life were analyzed thorough a linear regression model. 1) We observed a general increase in the number of reviews published from 2003 to 2016; 2) two reviews collected the 33% of the overall citations; 3) citation counting for clinical and mixed population collected the 90% of total citations; 4) clinical reviews had higher cumulative citation per publication/year growth. As mindfulness research advances, higher attention should be given to the mechanisms by which mindfulness interventions work so as to provide fruitful insights for future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A Moment of Mindfulness: Computer-Mediated Mindfulness Practice Increases State Mindfulness.

    Directory of Open Access Journals (Sweden)

    Lynsey Mahmood

    Full Text Available Three studies investigated the use of a 5-minute, computer-mediated mindfulness practice in increasing levels of state mindfulness. In Study 1, 54 high school students completed the computer-mediated mindfulness practice in a lab setting and Toronto Mindfulness Scale (TMS scores were measured before and after the practice. In Study 2 (N = 90 and Study 3 (N = 61, the mindfulness practice was tested with an entirely online sample to test the delivery of the 5-minute mindfulness practice via the internet. In Study 2 and 3, we found a significant increase in TMS scores in the mindful condition, but not in the control condition. These findings highlight the impact of a brief, mindfulness practice for single-session, computer-mediated use to increase mindfulness as a state.

  2. Neuronal Networks on Nanocellulose Scaffolds.

    Science.gov (United States)

    Jonsson, Malin; Brackmann, Christian; Puchades, Maja; Brattås, Karoline; Ewing, Andrew; Gatenholm, Paul; Enejder, Annika

    2015-11-01

    Proliferation, integration, and neurite extension of PC12 cells, a widely used culture model for cholinergic neurons, were studied in nanocellulose scaffolds biosynthesized by Gluconacetobacter xylinus to allow a three-dimensional (3D) extension of neurites better mimicking neuronal networks in tissue. The interaction with control scaffolds was compared with cationized nanocellulose (trimethyl ammonium betahydroxy propyl [TMAHP] cellulose) to investigate the impact of surface charges on the cell interaction mechanisms. Furthermore, coatings with extracellular matrix proteins (collagen, fibronectin, and laminin) were investigated to determine the importance of integrin-mediated cell attachment. Cell proliferation was evaluated by a cellular proliferation assay, while cell integration and neurite propagation were studied by simultaneous label-free Coherent anti-Stokes Raman Scattering and second harmonic generation microscopy, providing 3D images of PC12 cells and arrangement of nanocellulose fibrils, respectively. Cell attachment and proliferation were enhanced by TMAHP modification, but not by protein coating. Protein coating instead promoted active interaction between the cells and the scaffold, hence lateral cell migration and integration. Irrespective of surface modification, deepest cell integration measured was one to two cell layers, whereas neurites have a capacity to integrate deeper than the cell bodies in the scaffold due to their fine dimensions and amoeba-like migration pattern. Neurites with lengths of >50 μm were observed, successfully connecting individual cells and cell clusters. In conclusion, TMAHP-modified nanocellulose scaffolds promote initial cellular scaffold adhesion, which combined with additional cell-scaffold treatments enables further formation of 3D neuronal networks.

  3. The Role of Parents' Distancing Strategies in the Development of Five-Year-Old Children's Theory of Mind

    Science.gov (United States)

    Galende, Nuria; de Miguel, Manuel Sanchez; Arranz, Enrique

    2012-01-01

    The aim of this study was to analyse the relation between parents' distancing strategies and the performance of five-year-old children (N = 70) in Theory of Mind (ToM) tasks. The children's performances were assessed during individual sessions held at school. The distancing strategies practiced by the parents (cognitive and linguistic scaffolding,…

  4. A Ternary Nanofibrous Scaffold Potential for Central Nerve System Tissue Engineering.

    Science.gov (United States)

    Saadatkish, Niloufar; Nouri Khorasani, Saied; Morshed, Mohammad; Allafchian, Ali-Reza; Beigi, Mohammad-Hossein; Masoudi Rad, Maryam; Nasr-Esfahani, Mohammad Hossein; Esmaeely Neisiany, Rasoul

    2018-04-10

    In the present research, a ternary Polycaprolactone (PCL)/gelatin/fibrinogen nanofibrous scaffold for tissue engineering application was developed. Through this combination, PCL improved the scaffold mechanical properties; meanwhile, gelatin and fibrinogen provided more hydrophilicity and cell proliferation. Three types of nanofibrous scaffolds containing different fibrinogen contents were prepared and characterized. Morphological study of the nanofibers showed that the prepared nanofibers were smooth, uniform without any formation of beads with a significant reduction in nanofiber diameter after incorporation of fibrinogen. The chemical characterization of the scaffolds confirmed that no chemical reaction occurred between the scaffold components. The tensile test results of the scaffolds showed that increasing in fibrinogen content led to a decrease in mechanical properties. Furthermore, Adipose-derived stem cells (ADSCs) were employed to evaluate cell-scaffold interaction. Cell culture results indicated that higher cell proliferation occurred for the higher amount of fibrinogen. Statistical analysis was also carried out to evaluate the significant difference for the obtained results of water droplet contact angle and cell culture. Therefore, the results confirmed that PCL/Gel/Fibrinogen scaffold has a good potential for tissue engineering applications including Central Nerve System (CNS) tissue engineering. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

  5. Development of nanofibrous scaffolds containing gum tragacanth/poly (ε-caprolactone) for application as skin scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Ranjbar-Mohammadi, Marziyeh [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Bahrami, S. Hajir, E-mail: hajirb@aut.ac.ir [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Center for excellence Modern Textile Characterization, Tehran (Iran, Islamic Republic of)

    2015-03-01

    Outstanding wound healing activity of gum tragacanth (GT) and higher mechanical strength of poly (ε-caprolactone) (PCL) may produce an excellent nanofibrous patch for either skin tissue engineering or wound dressing application. PCL/GT scaffold containing different concentrations of PCL with different blend ratios of GT/PCL was produced using 90% acetic acid as solvent. The results demonstrated that the PCL/GT (3:1.5) with PCL concentration of 20% (w/v) produced nanofibers with proper morphology. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were utilized to characterize the nanofibers. Surface wettability, functional groups analysis, porosity and tensile properties of nanofibers were evaluated. Morphological characterization showed that the addition of GT to PCL solution results in decreasing the average diameter of the PCL/GT nanofibers. However, the hydrophilicity increased in the PCL/GT nanofibers. Slight increase in melting peaks was observed due to the blending of PCL with GT nanofibers. PCL/GT nanofibers were used for in vitro cell culture of human fibroblast cell lines AGO and NIH 3T3 fibroblast cells. MTT assay and SEM results showed that the biocomposite PCL/GT mats enhanced the fibroblast adhesion and proliferation compared to PCL scaffolds. The antibacterial activity of PCL/GT and GT nanofibers against Staphylococcus aureus and Pseudomonas aeruginosa was also examined. - Highlights: • A new skin tissue engineering scaffold from poly (ε-caprolactone) (PCL) and gum tragacanth (GT) has been developed. • These scaffolds might be an effectual simulator of the structure and composition of native skin. • Very slight increase in melting peaks was observed due to the blending of PCL with GT nanofibers. • Biodegradation, water uptake and hydrophilicity properties of these scaffolds showed that produced scaffolds were adherent. • The electrospun PCL/GT scaffold can promote the skin regeneration of full

  6. Development of nanofibrous scaffolds containing gum tragacanth/poly (ε-caprolactone) for application as skin scaffolds

    International Nuclear Information System (INIS)

    Ranjbar-Mohammadi, Marziyeh; Bahrami, S. Hajir

    2015-01-01

    Outstanding wound healing activity of gum tragacanth (GT) and higher mechanical strength of poly (ε-caprolactone) (PCL) may produce an excellent nanofibrous patch for either skin tissue engineering or wound dressing application. PCL/GT scaffold containing different concentrations of PCL with different blend ratios of GT/PCL was produced using 90% acetic acid as solvent. The results demonstrated that the PCL/GT (3:1.5) with PCL concentration of 20% (w/v) produced nanofibers with proper morphology. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were utilized to characterize the nanofibers. Surface wettability, functional groups analysis, porosity and tensile properties of nanofibers were evaluated. Morphological characterization showed that the addition of GT to PCL solution results in decreasing the average diameter of the PCL/GT nanofibers. However, the hydrophilicity increased in the PCL/GT nanofibers. Slight increase in melting peaks was observed due to the blending of PCL with GT nanofibers. PCL/GT nanofibers were used for in vitro cell culture of human fibroblast cell lines AGO and NIH 3T3 fibroblast cells. MTT assay and SEM results showed that the biocomposite PCL/GT mats enhanced the fibroblast adhesion and proliferation compared to PCL scaffolds. The antibacterial activity of PCL/GT and GT nanofibers against Staphylococcus aureus and Pseudomonas aeruginosa was also examined. - Highlights: • A new skin tissue engineering scaffold from poly (ε-caprolactone) (PCL) and gum tragacanth (GT) has been developed. • These scaffolds might be an effectual simulator of the structure and composition of native skin. • Very slight increase in melting peaks was observed due to the blending of PCL with GT nanofibers. • Biodegradation, water uptake and hydrophilicity properties of these scaffolds showed that produced scaffolds were adherent. • The electrospun PCL/GT scaffold can promote the skin regeneration of full

  7. Effects of scaffold surface morphology on cell adhesion and survival rate in vitreous cryopreservation of tenocyte-scaffold constructs

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhi [State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041 (China); Department of Bone and Joint Surgery, The affiliated hospital of Luzhou Medical College, Luzhou 646000 (China); Qing, Quan [Sichuan College of Traditional Chinese Medicine, Mianyang 621000 (China); Regenerative Medicine Research Center, West China Hospital of Sichuan University, Chengdu 610041 (China); Chen, Xi; Liu, Cheng-Jun; Luo, Jing-Cong [State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041 (China); Hu, Jin-Lian [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Qin, Ting-Wu, E-mail: tingwuqin@hotmail.com [State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041 (China)

    2016-12-01

    Highlights: • The shapes of tenocytes varied when seeded on different surface of scaffolds. • Tenocytes were flat on smooth surface and spindle on micro-grooved surface. • Tenocytes were ellipse or spindle on porous surface. • Tenocytes got varying adhesion shape and elongation index on varying surfaces. • The tenocyte survival on porous surface was superior to the other two groups. - Abstract: The purpose of this study was to investigate the effects of scaffold surface morphology on cell adhesion and survival rate in vitreous cryopreservation of tenocyte-scaffold constructs. Tenocytes were obtained from tail tendons of rats. Polydimethylsiloxane (PDMS) was used to fabricate three types of scaffolds with varying surface morphological characteristics, i.e., smooth, micro-grooved, and porous surfaces, respectively. The tenocytes were seeded on the surfaces of the scaffolds to form tenocyte-scaffold constructs. The constructs were cryopreserved in a vitreous cryoprotectant (CPA) with a multi-step protocol. The cell adhesion to scaffolds was observed with electronic scanning microscopy (SEM). The elongation index of the living tenocytes and ratio of live/dead cell number were examined based on a live/dead dual fluorescent staining technique, and the survival rate of tenocytes was studied with flow cytometry (FC). The results showed the shapes of tenocytes varied between the different groups: flat or polygonal (on smooth surface), spindle (on micro-grooved surface), and spindle or ellipse (on porous surface). After thawing, the porous surface got the most living tenocytes and a higher survival rate, suggesting its potential application for vitreous cryopreservation of engineered tendon constructs.

  8. The balanced mind

    DEFF Research Database (Denmark)

    Allen, Micah; Smallwood, Jonathan; Christensen, Joanna

    2013-01-01

    Self-generated thoughts unrelated to ongoing activities, also known as "mind-wandering," make up a substantial portion of our daily lives. Reports of such task-unrelated thoughts (TUTs) predict both poor performance on demanding cognitive tasks and blood-oxygen-level-dependent (BOLD) activity...... in the default mode network (DMN). However, recent findings suggest that TUTs and the DMN can also facilitate metacognitive abilities and related behaviors. To further understand these relationships, we examined the influence of subjective intensity, ruminative quality, and variability of mind...

  9. Mindfulness e Inteligencia Emocional

    OpenAIRE

    Ruiz Ballesteros, Desirée

    2016-01-01

    En este trabajo se presenta una breve investigación sobre temas tan de actualidad como son mindfulness e inteligencia emocional. El objetivo principal es mostrar la relación existente entre ambos constructos, y mostrar la utilidad de integrar ambas disciplinas en el ámbito de la educación gracias a la revisión bibliográfica y a la investigación llevada a cabo. Por un lado, con el mindfulness tomamos conciencia de los acontecimientos internos y externos que experimentamos en cualquier momento ...

  10. Strong and biocompatible three-dimensional porous silk fibroin/graphene oxide scaffold prepared by phase separation.

    Science.gov (United States)

    Wang, Shu-Dong; Ma, Qian; Wang, Ke; Ma, Pi-Bo

    2018-05-01

    Silk fibroin (SF) is blended with graphene oxide (GO) to prepare the strong and biocompatible three dimensional porous SF/GO blended scaffold via phase separation. GO could be well dispersed in SF solution and GO could also be well distributed in the SF scaffold. Furthermore, the introduction of GO can lead to structural change in the bended scaffold. Higher concentration of GO resulted in more compact structure and smaller pore size of the composite scaffolds without decreasing their porosity. Scanning electron microscopy and energy dispersive spectrometry results also reveal that SF and GO are homogeneous blended together. Analysis of chemical structures of the scaffold shows that addition of GO do not affect the crystalline structure of SF and it is evenly blended with SF. The blended scaffold has significantly higher breaking strength than the pure SF scaffold. In vitro study indicates that both pure SF scaffold and SF/GO composite scaffold support growth and proliferation of MC3T3-E1 osteoprogenitor cells. However, the addition of GO contribute to the proliferation of MC3T3-E1 osteoprogenitor. The testing results show that the blended scaffold is an appropriate candidate for tissue engineering. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Mind-body interventions during pregnancy.

    Science.gov (United States)

    Beddoe, Amy E; Lee, Kathryn A

    2008-01-01

    To examine published evidence on the effectiveness of mind-body interventions during pregnancy on perceived stress, mood, and perinatal outcomes. Computerized searches of PubMed, Cinahl, PsycINFO, and the Cochrane Library. Twelve out of 64 published intervention studies between 1980 and February 2007 of healthy, adult pregnant women met criteria for review. Studies were categorized by type of mind-body modality used. Progressive muscle relaxation was the most common intervention. Other studies used a multimodal psychoeducation approach or a yoga and meditation intervention. The research contained methodological problems, primarily absence of a randomized control group or failure to adequately control confounding variables. Nonetheless, there was modest evidence for the efficacy of mind-body modalities during pregnancy. Treatment group outcomes included higher birthweight, shorter length of labor, fewer instrument-assisted births, and reduced perceived stress and anxiety. There is evidence that pregnant women have health benefits from mind-body therapies used in conjunction with conventional prenatal care. Further research is necessary to build on these studies in order to predict characteristics of subgroups that might benefit from mind-body practices and examine cost effectiveness of these interventions on perinatal outcomes.

  12. The Politics of Mindfulness. A Response to "Mindfulness, Democracy, Education"

    Science.gov (United States)

    Comstock, Patrick W.

    2015-01-01

    Mindfulness is rapidly becoming a mainstream educational intervention. A growing number of schools, colleges, and universities are incorporating mindfulness into the curriculum, and while there is a substantial body of research literature in psychology attesting to the mental and physical benefits of mindfulness, critics of the movement have…

  13. Materializing Mind: The Role of Objects in Cognition and Culture

    DEFF Research Database (Denmark)

    Tylén, Kristian; McGraw, John J.

    2014-01-01

    , and distributed cognition, we review and classify a set of cognitive processes mediated by material representations. Specifically, we ask how—in a range of everyday cognitive and cultural practices—we employ objects (1) to scaffold memory, (2) to alter cognitive complexity, (3) to facilitate epistemic......If mind is investigated as the set of interactions that accomplish a cognitive task, that is, if mind is more than that which occurs inside the head, then how does the interplay of biological and environmental resources produce human cognition? Informed by active externalism, joint action...... experimentation, (4) to enable the division of cognitive labor, (5) to promote confidence and trust, (6) to consolidate social structure, and (7) to support dialogical coupling. We conclude that through cultural practices the stable, “manipulable”, and public properties of objects have come to afford...

  14. Mindfulness handler ikke om individualisering

    DEFF Research Database (Denmark)

    Jensen, Christian Gaden

    2013-01-01

    Kommentar til indlæg i Ugebrevet A4 om, at mindfulness virker individualiserende på arbejdspladsen.......Kommentar til indlæg i Ugebrevet A4 om, at mindfulness virker individualiserende på arbejdspladsen....

  15. Mindfulness-Based Stress Reduction

    Science.gov (United States)

    ... R S T U V W X Y Z Mindfulness-Based Stress Reduction (MBSR) Information 6 Things You ... Disease and Dementia (12/20/13) Research Spotlights Mindfulness-Based Stress Reduction, Cognitive-Behavioral Therapy Shown To ...

  16. Mindfulness-baseret kognitiv terapi

    DEFF Research Database (Denmark)

    van der Velden, Anne Maj; Piet, Jacob; Møller, Anne Buch

    2017-01-01

    Mindfulness-based cognitive therapy (MBCT) is an evidencebased psychotherapeutic intervention, which integrates elements of cognitive behavioural therapy for depression with the clinical application of mindfulness meditation. MBCT is currently recommended in several national clinical guidelines a...

  17. The Mind-Body Problem.

    Science.gov (United States)

    Fodor, Jerry A.

    1981-01-01

    Describes several different philosophies of mind with each philosophy's explanation of the mind-body problem. Philosophies discussed include dualism, materialism, functionalism, radical behaviorism, logical behaviorism and central-state identity. (DS)

  18. Mindfulness Dampens Cardiac Responses to Motion Scenes of Violence.

    Science.gov (United States)

    Brzozowski, Artur; Gillespie, Steven M; Dixon, Louise; Mitchell, Ian J

    2018-01-01

    Mindfulness is linked with improved regulatory processes of attention and emotion. The potential benefits of mindfulness are vast, including more positive emotional states and diminished arousal in response to emotional stimuli. This study aims to expand of the current knowledge of the mechanisms of mindfulness by relating the latter to cardiovascular processes. The paper describes two studies which investigated the relationship of trait mindfulness to self-report measures of emotions elicited during a violent video clip and cardiovascular responses to the clip. Both studies recruited male and female participants, mainly university undergraduate students. The clip was 5-min-long and evoked mainly feelings of tension and disgust. In study 1, we found that higher scores for trait mindfulness were associated with increased scores for valence ( r  = .370, p  = .009), indicating a more positive interpretation of the clip. In study 2, the average heart rate during the clip was lower than during the preceding ( p  mindfulness was related to diminished heart rate reactivity ( r  = -.364, p  = .044) and recovery ( r  = -.415, p  = .020). This latter effect was obtained only when trait anxiety was used as a statistical covariate. Additionally, increased trait mindfulness was accompanied by higher resting heart rate ( r  = .390, p  = .027). These outcomes suggest that mindfulness is linked with reductions in negative feelings evoked by violent motion stimuli.

  19. Mind mapping in qualitative research.

    Science.gov (United States)

    Tattersall, Christopher; Powell, Julia; Stroud, James; Pringle, Jan

    We tested a theory that mind mapping could be used as a tool in qualitative research to transcribe and analyse an interview. We compared results derived from mind mapping with those from interpretive phenomenological analysis by examining patients' and carers' perceptions of a new nurse-led service. Mind mapping could be used to rapidly analyse simple qualitative audio-recorded interviews. More research is needed to establish the extent to which mind mapping can assist qualitative researchers.

  20. [Neurosciences and philosophy of mind].

    Science.gov (United States)

    Saal, Aarón

    2005-01-01

    In this paper we argue that the interaction between neurosciences and philosophy of the mind is on the way to understand consciousness, and to solve the mind-body or mind-brain problem. Naturalism is the view that mental processes are just brain processes and that consciousness is a natural phenomenon. It is possible to construct a theory about its nature by blending insights from neuroscience, philosophy of the mind, phenomenology, psychology and evolutionary biology.

  1. Fabrication and characterization of platelet-rich plasma scaffolds for tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi-Ataabadi, Mahmoud [Tissue engineering Lab, Anatomy department, Medical School, Shiraz University of Medical Sciences (Iran, Islamic Republic of); Mostafavi-pour, Zohreh [Recombinant protein lab, Department of Biochemistry, Medical School, Shiraz University of Medical Sciences (Iran, Islamic Republic of); Vojdani, Zahra; Sani, Mahsa [Tissue engineering Lab, Anatomy department, Medical School, Shiraz University of Medical Sciences (Iran, Islamic Republic of); Latifi, Mona [Tissue Engineering Department, National Institute of Genetic Engineering and Biotechnoloy (Iran, Islamic Republic of); Tissue engineering Lab, Anatomy department, Medical School, Shiraz University of Medical Sciences (Iran, Islamic Republic of); Talaei-Khozani, Tahereh, E-mail: talaeit@sums.ac.ir [Tissue engineering Lab, Anatomy department, Medical School, Shiraz University of Medical Sciences (Iran, Islamic Republic of)

    2017-02-01

    Platelet-Rich Plasma (PRP), as a rich source of growth factor, can form a fibrin gel that recapitulates the extracellular matrix of the tissues. The aim of this study was to evaluate the effects of different concentrations of CaCl{sub 2} on the PRP scaffold structure which in turn could change the cell's behavior. PRP was mixed with 2.5, 5 and 10% (w/v) CaCl{sub 2}. Then, the tensile strength, biodegradability and water content of the scaffolds were evaluated. We also performed immunostaining for assessment of the actin stress fiber orientation and SEM for detecting the cell phenotype and physical properties of the fibers. Cell viability, attachment and migration were also evaluated. The highest cell attachment and short term proliferation rate was observed on the scaffolds with 2.5% CaCl{sub 2}. The cells cultured on the scaffold with higher CaCl{sub 2} concentration had fusiform phenotype with few cell processes and parallel arrangement of stress fibers while those cultured on the other scaffolds were fibroblast-like with more processes and net-like stress fibers. The scaffolds with 10% CaCl{sub 2} demonstrated the highest osmolarity (358.75 ± 4.99 mOsmole), fiber thickness (302.1 ± 54.3 nm), pore size (332.1 ± 118.9 nm{sup 2}) and the longest clotting time (12.2 ± 0.776 min) compared with the other scaffolds. Water content, branching angle, porosity, orientation and tensile strength did not change by gelation with different CaCl{sub 2} concentrations. In conclusion, the cell shape, viability and proliferation were modified by culturing on the PRP scaffolds prepared with various concentrations of CaCl{sub 2}, and as a result, the scaffolds showed different physical and biological properties - Highlights: Platelet rich plasma (PRP) can be considered as an autologous source for tissue engineering applications. Cell shape, function and differentiation fate are influenced by the mechanical and physical features of the scaffolds. Different CaCl2

  2. Fabrication and characterization of platelet-rich plasma scaffolds for tissue engineering applications

    International Nuclear Information System (INIS)

    Sadeghi-Ataabadi, Mahmoud; Mostafavi-pour, Zohreh; Vojdani, Zahra; Sani, Mahsa; Latifi, Mona; Talaei-Khozani, Tahereh

    2017-01-01

    Platelet-Rich Plasma (PRP), as a rich source of growth factor, can form a fibrin gel that recapitulates the extracellular matrix of the tissues. The aim of this study was to evaluate the effects of different concentrations of CaCl 2 on the PRP scaffold structure which in turn could change the cell's behavior. PRP was mixed with 2.5, 5 and 10% (w/v) CaCl 2 . Then, the tensile strength, biodegradability and water content of the scaffolds were evaluated. We also performed immunostaining for assessment of the actin stress fiber orientation and SEM for detecting the cell phenotype and physical properties of the fibers. Cell viability, attachment and migration were also evaluated. The highest cell attachment and short term proliferation rate was observed on the scaffolds with 2.5% CaCl 2 . The cells cultured on the scaffold with higher CaCl 2 concentration had fusiform phenotype with few cell processes and parallel arrangement of stress fibers while those cultured on the other scaffolds were fibroblast-like with more processes and net-like stress fibers. The scaffolds with 10% CaCl 2 demonstrated the highest osmolarity (358.75 ± 4.99 mOsmole), fiber thickness (302.1 ± 54.3 nm), pore size (332.1 ± 118.9 nm 2 ) and the longest clotting time (12.2 ± 0.776 min) compared with the other scaffolds. Water content, branching angle, porosity, orientation and tensile strength did not change by gelation with different CaCl 2 concentrations. In conclusion, the cell shape, viability and proliferation were modified by culturing on the PRP scaffolds prepared with various concentrations of CaCl 2 , and as a result, the scaffolds showed different physical and biological properties - Highlights: Platelet rich plasma (PRP) can be considered as an autologous source for tissue engineering applications. Cell shape, function and differentiation fate are influenced by the mechanical and physical features of the scaffolds. Different CaCl2 concentrations modified some features of the PRP

  3. Mindful Social Work?

    Directory of Open Access Journals (Sweden)

    Debaene, Raf

    2009-12-01

    Full Text Available Mindfulness gets growing attention in the education and practice of social work. It is seen as an important source of inspiration for social work and as a counterbalance for the rationalization of social work. Hick states that mindfulness “is an orientation to our everyday experiences that can be cultivated by means of various exercises and practices. By opening up in a particular way to their internal and external experiences, social workers and clients are better able to understand what is happening to them in both a psychological and sociological sense. With this understanding, people are better able to see the variety of ways in which they can respond. Habitual reactions are more easily avoided, and inner peace and balance are developed” (Hick 2009: 1. Despite this praise of mindfulness as an important source of inspiration and the expectation that its popularity might expand in the next century, it is argued in this essay by Raf Debaene that mindfulness, although possibly very useful in some settings, had very little to do with social work.

  4. MIND performance and prototyping

    International Nuclear Information System (INIS)

    Cervera-Villanueva, A.

    2008-01-01

    The performance of MIND (Magnetised Iron Neutrino Detector) at a neutrino factory has been revisited in a new analysis. In particular, the low neutrino energy region is studied, obtaining an efficiency plateau around 5 GeV for a background level below 10 -3 . A first look has been given into the detector optimisation and prototyping

  5. Goedel, relativity, and mind

    International Nuclear Information System (INIS)

    Penrose, Roger

    2007-01-01

    Goedel's acquaintance with Einstein led him to discover, by use of novel techniques, an exotic cosmological model which flouted many preconceived notions, such as the role of Mach's principle in general relativity and the nature of time. Goedel also invoked it in speculations concerning the question of minds

  6. Capturing Thoughts, Capturing Minds?

    DEFF Research Database (Denmark)

    Nielsen, Janni

    2004-01-01

    Think Aloud is cost effective, promises access to the user's mind and is the applied usability technique. But 'keep talking' is difficult, besides, the multimodal interface is visual not verbal. Eye-tracking seems to get around the verbalisation problem. It captures the visual focus of attention...

  7. A Matter of Mindfulness.

    Science.gov (United States)

    Jacobs, Richard M.

    1998-01-01

    Advises Catholic school principals to find a quiet place each day where distractions can be placed aside for 15 minutes to contemplate spirituality. Argues that by allowing their relationship with God to permeate their busy administration, principals' mindfulness can help foster school spirituality by providing catechetical leadership for their…

  8. Attachment Theory and Mindfulness

    Science.gov (United States)

    Snyder, Rose; Shapiro, Shauna; Treleaven, David

    2012-01-01

    We initiate a dialog between two central areas in the field of psychology today: attachment theory/research and mindfulness studies. The impact of the early mother-infant relationship on child development has been well established in the literature, with attachment theorists having focused on the correlation between a mother's capacity for…

  9. Theory of mind.

    Science.gov (United States)

    Carlson, Stephanie M; Koenig, Melissa A; Harms, Madeline B

    2013-07-01

    Theory of mind and its development has been a significantly important-and challenging-topic of research in cognitive science for three decades. This review summarizes our knowledge of when and how children come to understand their own and others' minds, including the developmental timetable, old and new measures, and foundational skills in infancy. We review recent research on theory-of-mind (ToM) and learning, that is, ways in which children's understanding of other minds informs how they learn about the world, as well as evidence for an important role of domain-general cognitive skills (executive function) in the development of ToM, and the neural networks that are most strongly implicated. Finally, we propose future directions for research in this vast and growing field. WIREs Cogn Sci 2013, 4:391-402. doi: 10.1002/wcs.1232 The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Minding Rachlin's Eliminative Materialism

    Science.gov (United States)

    McDowell, J. J.

    2012-01-01

    Rachlin's teleological behaviorism eliminates the first-person ontology of conscious experience by identifying mental states with extended patterns of behavior, and thereby maintains the materialist ontology of science. An alternate view, informed by brain-based and externalist philosophies of mind, is shown also to maintain the materialist…

  11. The embodied mind

    DEFF Research Database (Denmark)

    Bondebjerg, Ib

    2015-01-01

    Since the 1980s the study of the brain has developed from a primarily biological field to a significant interdisciplinary area with an already strong influence on the humanities and social sciences. In this article I describe fundamental elements in what I call the embodied mind paradigm and the ...

  12. Mindfulness and Situation Awareness

    Science.gov (United States)

    2011-06-01

    The expert mind has its value: for example, Pasteur argued that “in the fields of observation chance favours only the prepared mind” 1. Garrett...and listen intently. Avoid lumping details together or attempting to normalize an unexpected event in order to preserve a preconceived expectation

  13. Hybrid Carbon-Based Scaffolds for Applications in Soft Tissue Reconstruction

    Science.gov (United States)

    Lafdi, Khalid; Joseph, Robert M.; Tsonis, Panagiotis A.

    2012-01-01

    Current biomedical scaffolds utilized in surgery to repair soft tissues commonly fail to meet the optimal combination of biomechanical and tissue regenerative properties. Carbon is a scaffold alternative that potentially optimizes the balance between mechanical strength, durability, and function as a cell and biologics delivery vehicle that is necessary to restore tissue function while promoting tissue repair. The goals of this study were to investigate the feasibility of fabricating hybrid fibrous carbon scaffolds modified with biopolymer, polycaprolactone and to analyze their mechanical properties and ability to support cell growth and proliferation. Environmental scanning electron microscopy, micro-computed tomography, and cell adhesion and cell proliferation studies were utilized to test scaffold suitability as a cell delivery vehicle. Mechanical properties were tested to examine load failure and elastic modulus. Results were compared to an acellular dermal matrix scaffold control (GraftJacket® [GJ] Matrix), selected for its common use in surgery for the repair of soft tissues. Results indicated that carbon scaffolds exhibited similar mechanical maximums and capacity to support fibroblast adhesion and proliferation in comparison with GJ. Fibroblast adhesion and proliferation was collinear with carbon fiber orientation in regions of sparsely distributed fibers and occurred in clusters in regions of higher fiber density and low porosity. Overall, fibroblast adhesion and proliferation was greatest in lower porosity carbon scaffolds with highly aligned fibers. Stepwise multivariate regression showed that the variability in maximum load of carbon scaffolds and controls were dependent on unique and separate sets of parameters. These finding suggested that there were significant differences in the functional implications of scaffold design and material properties between carbon and dermis derived scaffolds that affect scaffold utility as a tissue replacement

  14. Preparation and characterization of biohybrid poly (3-hydroxybutyrate-co-3-hydroxyvalerate) based nanofibrous scaffolds

    Science.gov (United States)

    Kouhi, Monireh; Fathi, Mohammadhossein; Venugopal, Jayarama Reddy; Shamanian, Morteza; Ramakrishna, Seeram

    2018-01-01

    Development of bioengineered scaffolds for bone tissue regeneration is a growing area of research, especially those involving biodegradable electrospun nanofibers incorporated with ceramic nanoparticles, since they can mimic the extracellular matrix (ECM) of the native bone. In the current study, a biocomposite nanofibrous scaffolds consisting of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), fibrinogen (FIB) and bredigite (BR) nanoparticles was fabricated through electrospinning. The morphological, chemical and mechanical characteristics of the resultant scaffolds were studied by using field emission-scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR) and tensile tester, respectively. It was found that PHBV-FIB-BR scaffolds exhibited enhanced tensile strength and young modulus compared to PHBV and PHBV-FIB scaffolds. In addition, the measurements of the water contact angle suggested that incorporation of bredigite and fibrinogen into PHBV could improve the hydrophilicity of the composites. The results of bioactivity assessment performed in the simulated body fluid (SBF) demonstrated that the presence of the bredigite nanoparticles induced the nucleation and growth of apatite layer on the surface of PHBV-FIB-BR scaffold in SBF. Furthermore, the ion concentration changes of SBF solutions with composite scaffolds showed that PHBV-FIB-BR scaffolds released Ca and Si ions, which can stimulate osteoblast proliferation. The results of cell culture studies revealed the higher osteoblast proliferation, mineralization and differentiation on PHBV-FIB-BR and PHBV-FIB scaffolds than on PHBV. Our results suggest that PHBV-FIB-BR nanofibrous scaffold would be a promising candidate as a biocomposite nanofibrous scaffold material for tissue engineering applications.

  15. Mechanical anisotropy of titanium scaffolds

    Directory of Open Access Journals (Sweden)

    Rüegg Jasmine

    2017-09-01

    Full Text Available The clinical performance of an implant, e.g. for the treatment of large bone defects, depends on the implant material, anchorage, surface topography and chemistry, but also on the mechanical properties, like the stiffness. The latter can be adapted by the porosity. Whereas foams show isotropic mechanical properties, digitally modelled scaffolds can be designed with anisotropic behaviour. In this study, we designed and produced 3D scaffolds based on an orthogonal architecture and studied its angle-dependent stiffness. The aim was to produce scaffolds with different orientations of the microarchitecture by selective laser melting and compare the angle-specific mechanical behaviour with an in-silico simulation. The anisotropic characteristics of open-porous implants and technical limitations of the production process were studied.

  16. A scaffold easy to decontaminate

    International Nuclear Information System (INIS)

    Mourek, D.

    1992-01-01

    The conventional scaffold used in the assembling work and in revisions of technological facilities at nuclear power plants has many drawbacks. The most serious of them are a high amount of radioactive waste arising from the decontamination (planing) of the floor timber and from the discarding of damaged irreparable parts, and a considerable corrosion of the carbon steel supporting structure after the decontamination. A detailed description is given of a novel scaffold assembly which can be decontaminated and which exhibits many assets, in particular a good mechanical resistance (also to bad weather), a lower weight, and the use of prepreg floor girders for the construction of service platforms or scaffold bridges which can readily be assembled from the pressed pieces in a modular way. (Z.S.). 4 figs., 4 refs

  17. Does Mindfulness Enhance Critical Thinking? Evidence for the Mediating Effects of Executive Functioning in the Relationship between Mindfulness and Critical Thinking

    OpenAIRE

    Noone, Chris; Bunting, Brendan; Hogan, Michael J.

    2016-01-01

    Mindfulness originated in the Buddhist tradition as a way of cultivating clarity of thought. Despite the fact that this behaviour is best captured using critical thinking assessments, no studies have examined the effects of mindfulness on critical thinking or the mechanisms underlying any such possible relationship. Even so, mindfulness has been suggested as being beneficial for critical thinking in higher education. Critical thinking is recognised as an important higher-order cognitive proce...

  18. Mindfulness Meditation-Based Pain Relief Employs Different Neural Mechanisms Than Placebo and Sham Mindfulness Meditation-Induced Analgesia.

    Science.gov (United States)

    Zeidan, Fadel; Emerson, Nichole M; Farris, Suzan R; Ray, Jenna N; Jung, Youngkyoo; McHaffie, John G; Coghill, Robert C

    2015-11-18

    significantly reduces pain. Given that the "gold standard" for evaluating the efficacy of behavioral interventions is based on appropriate placebo comparisons, it is imperative that we establish whether there is an effect supporting meditation-related pain relief above and beyond the effects of placebo. Here, we provide novel evidence demonstrating that mindfulness meditation produces greater pain relief and employs distinct neural mechanisms than placebo cream and sham mindfulness meditation. Specifically, mindfulness meditation-induced pain relief activated higher-order brain regions, including the orbitofrontal and cingulate cortices. In contrast, placebo analgesia was associated with decreased pain-related brain activation. These findings demonstrate that mindfulness meditation reduces pain through unique mechanisms and may foster greater acceptance of meditation as an adjunct pain therapy. Copyright © 2015 the authors 0270-6474/15/3515308-19$15.00/0.

  19. Mindful Emotion Regulation: Exploring the Neurocognitive Mechanisms behind Mindfulness

    Directory of Open Access Journals (Sweden)

    Alessandro Grecucci

    2015-01-01

    Full Text Available The purpose of this paper is to review some of the psychological and neural mechanisms behind mindfulness practice in order to explore the unique factors that account for its positive impact on emotional regulation and health. After reviewing the mechanisms of mindfulness and its effects on clinical populations we will consider how the practice of mindfulness contributes to the regulation of emotions. We argue that mindfulness has achieved effective outcomes in the treatment of anxiety, depression, and other psychopathologies through the contribution of mindfulness to emotional regulation. We consider the unique factors that mindfulness meditation brings to the process of emotion regulation that may account for its effectiveness. We review experimental evidence that points towards the unique effects of mindfulness specifically operating over and above the regulatory effects of cognitive reappraisal mechanisms. A neuroanatomical circuit that leads to mindful emotion regulation is also suggested. This paper thereby aims to contribute to proposed models of mindfulness for research and theory building by proposing a specific model for the unique psychological and neural processes involved in mindful detachment that account for the effects of mindfulness over and above the effects accounted for by other well-established emotional regulation processes such as cognitive reappraisal.

  20. Systematic Prediction of Scaffold Proteins Reveals New Design Principles in Scaffold-Mediated Signal Transduction

    Science.gov (United States)

    Hu, Jianfei; Neiswinger, Johnathan; Zhang, Jin; Zhu, Heng; Qian, Jiang

    2015-01-01

    Scaffold proteins play a crucial role in facilitating signal transduction in eukaryotes by bringing together multiple signaling components. In this study, we performed a systematic analysis of scaffold proteins in signal transduction by integrating protein-protein interaction and kinase-substrate relationship networks. We predicted 212 scaffold proteins that are involved in 605 distinct signaling pathways. The computational prediction was validated using a protein microarray-based approach. The predicted scaffold proteins showed several interesting characteristics, as we expected from the functionality of scaffold proteins. We found that the scaffold proteins are likely to interact with each other, which is consistent with previous finding that scaffold proteins tend to form homodimers and heterodimers. Interestingly, a single scaffold protein can be involved in multiple signaling pathways by interacting with other scaffold protein partners. Furthermore, we propose two possible regulatory mechanisms by which the activity of scaffold proteins is coordinated with their associated pathways through phosphorylation process. PMID:26393507

  1. Scaffolds for bone regeneration made of hydroxyapatite microspheres in a collagen matrix

    Energy Technology Data Exchange (ETDEWEB)

    Cholas, Rahmatullah, E-mail: rahmat.cholas@gmail.com; Kunjalukkal Padmanabhan, Sanosh, E-mail: sanosh2001@gmail.com; Gervaso, Francesca; Udayan, Gayatri; Monaco, Graziana; Sannino, Alessandro; Licciulli, Antonio

    2016-06-01

    drying • Compressive modulus of composite scaffold was higher than of pure collagen scaffold. • Cell proliferation with MG63 cells shows good biocompatiblity of composite scaffold.

  2. PENGARUH E-SCAFFOLDING DALAM THINK PAIR SHARE TERHADAP KEMAMPUAN BERPIKIR TINGKAT TINGGI DINAMIKA PARTIKEL

    Directory of Open Access Journals (Sweden)

    Akhmad Fauzul Albab

    2016-01-01

    Full Text Available Abstract: This study aimed to examine the effect of e-learning based Think Pair Share cooperative learning model toward higher order thinking skills of students. This study was conducted at SMAN 1 Jember for X grade students and used factorial design. Two experimental groups (TPS with E-Scaffolding and TPS with scaffolding were compared with a control group (TPS. This research was carried out to 180 students. The results showed that there is a difference in high-order thinking skills among groups of students who take the e-scaffolding in the TPS, scaffolding in TPS, and TPS learning; there is a difference in high-order thinking skills among groups of students with different prior knowledge levels; and there is no interactional effect among e-scaffolding in TPS, scaffolding in TPS and TPS strategy and the student’s prior knowledge on high order thinking skills. Key words: e-scaffolding, think pair share, high order thinking, prior knowledge.                                                                                     Abstrak: Penelitian ini bertujuan untuk menguji pengaruh pembelajaran berbasis e-learning yang terintegrasi dalam model pembelajaran kooperatif Think Pair Share (TPS dalam bentuk E-Scaffolding terhadap kemampuan berpikir tingkat tinggi siswa. Penelitian dilaksanakan di SMA Negeri 1 Jember untuk siswa kelas X ini dengan menggunakan rancangan faktorial. Dua kelompok eksperimen (TPS dengan E-Scaffolding dan TPS dengan Scaffolding dibandingkan dengan sebuah kelompok kontrol (TPS. Penelitian dilaksanakan terhadap sampel sebanyak 180 siswa yang dipilih secara acak kelompok. Hasil penelitian menunjukkan bahwa terdapat perbedaan kemampuan berpikir tingkat tinggi antara kelompok siswa yang mengikuti pembelajaran e-scaffolding dalam TPS dengan pembelajaran scaffolding dalam TPS maupun siswa dengan pembelajaran TPS; terdapat perbedaan kemampuan berpikir

  3. Scaffolding Singaporean Students to Write Vividly in the Chinese ‘Mother Tongue’, Mandarin

    Directory of Open Access Journals (Sweden)

    Tzemin Chung

    2014-02-01

    Full Text Available This paper details results from a three-year study investigating how to help students in Singapore write vivid compositions in Mandarin, the Chinese ‘mother tongue’. Mastery of the mother tongue by Singaporean students has become an important government priority in recent years. The strategies employed by this study included the use of information and communications technology (ICT mediated scaffolds such as collaborative mind maps and online peer editing to help students learn micro-writing strategies. This paper outlines the process of using various scaffolds to support students to learn and apply the action chain micro-writing strategy. A class of 31 Primary 4 from a neighbourhood school participated in this study. Findings indicated that students were very enthusiastic about writing in the ICT-mediated environment. Contrary to the teacher’s initial belief, students could be scaffolded to write action chains quickly. Findings highlighted the potential of scaffolding students in learning small chunks of writing strategy in an ICT-mediated environment that enabled them to practice these strategies in their composition writing until they could master and apply them. These micro-writing strategies gradually built up to a complex set of skills, including expressive writing. Moreover, students enjoyed working in groups and editing their peers’ work online. This showed that peers could be engaged as scaffolders in the classroom to free up the teacher’ time, allowing the teacher more time to spend with students who were not performing well.

  4. Porous allograft bone scaffolds: doping with strontium.

    Directory of Open Access Journals (Sweden)

    Yantao Zhao

    Full Text Available Strontium (Sr can promote the process of bone formation. To improve bioactivity, porous allograft bone scaffolds (ABS were doped with Sr and the mechanical strength and bioactivity of the scaffolds were evaluated. Sr-doped ABS were prepared using the ion exchange method. The density and distribution of Sr in bone scaffolds were investigated by inductively coupled plasma optical emission spectrometry (ICP-OES, X-ray photoelectron spectroscopy (XPS, and energy-dispersive X-ray spectroscopy (EDS. Controlled release of strontium ions was measured and mechanical strength was evaluated by a compressive strength test. The bioactivity of Sr-doped ABS was investigated by a simulated body fluid (SBF assay, cytotoxicity testing, and an in vivo implantation experiment. The Sr molar concentration [Sr/(Sr+Ca] in ABS surpassed 5% and Sr was distributed nearly evenly. XPS analyses suggest that Sr combined with oxygen and carbonate radicals. Released Sr ions were detected in the immersion solution at higher concentration than calcium ions until day 30. The compressive strength of the Sr-doped ABS did not change significantly. The bioactivity of Sr-doped material, as measured by the in vitro SBF immersion method, was superior to that of the Sr-free freeze-dried bone and the Sr-doped material did not show cytotoxicity compared with Sr-free culture medium. The rate of bone mineral deposition for Sr-doped ABS was faster than that of the control at 4 weeks (3.28 ± 0.23 µm/day vs. 2.60 ± 0.20 µm/day; p<0.05. Sr can be evenly doped into porous ABS at relevant concentrations to create highly active bone substitutes.

  5. Reading wild minds: A computational assay of Theory of Mind sophistication across seven primate species.

    Directory of Open Access Journals (Sweden)

    Marie Devaine

    2017-11-01

    Full Text Available Theory of Mind (ToM, i.e. the ability to understand others' mental states, endows humans with highly adaptive social skills such as teaching or deceiving. Candidate evolutionary explanations have been proposed for the unique sophistication of human ToM among primates. For example, the Machiavellian intelligence hypothesis states that the increasing complexity of social networks may have induced a demand for sophisticated ToM. This type of scenario ignores neurocognitive constraints that may eventually be crucial limiting factors for ToM evolution. In contradistinction, the cognitive scaffolding hypothesis asserts that a species' opportunity to develop sophisticated ToM is mostly determined by its general cognitive capacity (on which ToM is scaffolded. However, the actual relationships between ToM sophistication and either brain volume (a proxy for general cognitive capacity or social group size (a proxy for social network complexity are unclear. Here, we let 39 individuals sampled from seven non-human primate species (lemurs, macaques, mangabeys, orangutans, gorillas and chimpanzees engage in simple dyadic games against artificial ToM players (via a familiar human caregiver. Using computational analyses of primates' choice sequences, we found that the probability of exhibiting a ToM-compatible learning style is mainly driven by species' brain volume (rather than by social group size. Moreover, primates' social cognitive sophistication culminates in a precursor form of ToM, which still falls short of human fully-developed ToM abilities.

  6. Rhombicuboctahedron unit cell based scaffolds for bone regeneration: geometry optimization with a mechanobiology - driven algorithm.

    Science.gov (United States)

    Boccaccio, Antonio; Fiorentino, Michele; Uva, Antonio E; Laghetti, Luca N; Monno, Giuseppe

    2018-02-01

    In a context more and more oriented towards customized medical solutions, we propose a mechanobiology-driven algorithm to determine the optimal geometry of scaffolds for bone regeneration that is the most suited to specific boundary and loading conditions. In spite of the huge number of articles investigating different unit cells for porous biomaterials, no studies are reported in the literature that optimize the geometric parameters of such unit cells based on mechanobiological criteria. Parametric finite element models of scaffolds with rhombicuboctahedron unit cell were developed and incorporated into an optimization algorithm that combines them with a computational mechanobiological model. The algorithm perturbs iteratively the geometry of the unit cell until the best scaffold geometry is identified, i.e. the geometry that allows to maximize the formation of bone. Performances of scaffolds with rhombicuboctahedron unit cell were compared with those of other scaffolds with hexahedron unit cells. We found that scaffolds with rhombicuboctahedron unit cell are particularly suited for supporting medium-low loads, while, for higher loads, scaffolds with hexahedron unit cells are preferable. The proposed algorithm can guide the orthopaedic/surgeon in the choice of the best scaffold to be implanted in a patient-specific anatomic region. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Continuous cellularization of calcium phosphate hybrid scaffolds induced by plasma polymer activation

    International Nuclear Information System (INIS)

    Bergemann, Claudia; Cornelsen, Matthias; Quade, Antje; Laube, Thorsten; Schnabelrauch, Matthias; Rebl, Henrike; Weißmann, Volker; Seitz, Hermann; Nebe, Barbara

    2016-01-01

    The generation of hybrid materials based on β-tricalcium phosphate (TCP) and various biodegradable polymers like poly(L-lactide-co-D,L-lactide) (PLA) represents a common approach to overcoming the disadvantages of pure TCP devices. These disadvantages lie in TCP's mechanical properties, such as brittleness. The positive characteristic of PLA — improvement of compressive strength of calcium phosphate scaffolds – is diametrically opposed to its cell attractiveness. Therefore, the objective of this work was to optimize osteoblast migration and cellularization inside a three-dimensionally (3D) printed, PLA polymer stabilized TCP hybrid scaffold by a plasma polymer process depositing amino groups via allylamine. MG-63 osteoblastic cells inside the 10 mm hybrid scaffold were dynamically cultivated for 14 days in a 3D model system integrated in a perfusion reactor. The whole TCP/PLA hybrid scaffold was continuously colonized due to plasma polymerized allylamine activation inducing the migration potential of osteoblasts. - Highlights: • Mechanical stabilization of β-tricalcium phosphate scaffolds by PLA infiltration • Hybrid scaffolds with higher cell attraction due to plasma polymerized allylamine • 3D perfusion in vitro model for observation of cell migration inside scaffolds • Enhanced cell migration within plasma polymer coated TCP hybrid scaffolds

  8. Evaluating protein incorporation and release in electrospun composite scaffolds for bone tissue engineering applications.

    Science.gov (United States)

    Briggs, Tonye; Matos, Jeffrey; Collins, George; Arinzeh, Treena Livingston

    2015-10-01

    Electrospun polymer/ceramic composites have gained interest for use as scaffolds for bone tissue engineering applications. In this study, we investigated methods to incorporate Platelet Derived Growth Factor-BB (PDGF-BB) in electrospun polycaprolactone (PCL) or PCL prepared with polyethylene oxide (PEO), where both contained varying levels (up to 30 wt %) of ceramic composed of biphasic calcium phosphates, hydroxyapatite (HA)/β-tricalcium phosphate (TCP). Using a model protein, lysozyme, we compared two methods of protein incorporation, adsorption and emulsion electrospinning. Adsorption of lysozyme on scaffolds with ceramic resulted in minimal release of lysozyme over time. Using emulsion electrospinning, lysozyme released from scaffolds containing a high concentration of ceramic where the majority of the release occurred at later time points. We investigated the effect of reducing the electrostatic interaction between the protein and the ceramic on protein release with the addition of the cationic surfactant, cetyl trimethylammonium bromide (CTAB). In vitro release studies demonstrated that electrospun scaffolds prepared with CTAB released more lysozyme or PDGF-BB compared with scaffolds without the cationic surfactant. Human mesenchymal stem cells (MSCs) on composite scaffolds containing PDGF-BB incorporated through emulsion electrospinning expressed higher levels of osteogenic markers compared to scaffolds without PDGF-BB, indicating that the bioactivity of the growth factor was maintained. This study revealed methods for incorporating growth factors in polymer/ceramic scaffolds to promote osteoinduction and thereby facilitate bone regeneration. © 2015 Wiley Periodicals, Inc.

  9. Continuous cellularization of calcium phosphate hybrid scaffolds induced by plasma polymer activation

    Energy Technology Data Exchange (ETDEWEB)

    Bergemann, Claudia [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany); Cornelsen, Matthias [University of Rostock, Fluid Technology and Microfluidics, Justus-von-Liebig Weg 6, D-18059 Rostock (Germany); Quade, Antje [Leibniz-Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany); Laube, Thorsten; Schnabelrauch, Matthias [INNOVENT e.V., Biomaterials Department, Pruessingstrasse 27B, D-07745 Jena (Germany); Rebl, Henrike [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany); Weißmann, Volker [Institute for Polymer Technologies (IPT) e.V., Alter Holzhafen 19, D-23966 Wismar (Germany); Seitz, Hermann [University of Rostock, Fluid Technology and Microfluidics, Justus-von-Liebig Weg 6, D-18059 Rostock (Germany); Nebe, Barbara, E-mail: barbara.nebe@med.uni-rostock.de [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany)

    2016-02-01

    The generation of hybrid materials based on β-tricalcium phosphate (TCP) and various biodegradable polymers like poly(L-lactide-co-D,L-lactide) (PLA) represents a common approach to overcoming the disadvantages of pure TCP devices. These disadvantages lie in TCP's mechanical properties, such as brittleness. The positive characteristic of PLA — improvement of compressive strength of calcium phosphate scaffolds – is diametrically opposed to its cell attractiveness. Therefore, the objective of this work was to optimize osteoblast migration and cellularization inside a three-dimensionally (3D) printed, PLA polymer stabilized TCP hybrid scaffold by a plasma polymer process depositing amino groups via allylamine. MG-63 osteoblastic cells inside the 10 mm hybrid scaffold were dynamically cultivated for 14 days in a 3D model system integrated in a perfusion reactor. The whole TCP/PLA hybrid scaffold was continuously colonized due to plasma polymerized allylamine activation inducing the migration potential of osteoblasts. - Highlights: • Mechanical stabilization of β-tricalcium phosphate scaffolds by PLA infiltration • Hybrid scaffolds with higher cell attraction due to plasma polymerized allylamine • 3D perfusion in vitro model for observation of cell migration inside scaffolds • Enhanced cell migration within plasma polymer coated TCP hybrid scaffolds.

  10. A study on improving mechanical properties of porous HA tissue engineering scaffolds by hot isostatic pressing

    International Nuclear Information System (INIS)

    Zhao Jing; Xiao Suguang; Lu Xiong; Wang Jianxin; Weng Jie

    2006-01-01

    Various interconnected porous hydroxyapatite (HA) ceramic scaffolds are universally used to induct the tissue growth for bone repair and replacement, and serve to support the adhesion, transfer, proliferation and differentiation of cells. Impregnation of polyurethane sponges with a ceramic slurry is adopted to produce highly porous HA ceramic scaffolds with a 3D interconnected structure. However, high porosity always accompanies a decrease in the strength of the HA ceramic scaffolds. Therefore, it is significant to improve the strength of the HA ceramic scaffolds with highly interconnected porosity so that they are more suitable in clinical applications. In this work, highly porous HA ceramic scaffolds are first produced by the polymer impregnation approach, and subsequently further sintered by hot isostatic pressing (HIP). The phase composition, macro- and micro-porous structure, sintering and mechanical properties of the porous HA scaffolds are investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), nanoindentation analysis and compressive test. The experimental results show that the nanohardness and compressive strength of HIP-sintered porous HA ceramics are higher than those of commonly sintered HA scaffolds. The HIP technique can effectively improve the sintering property and densification of porous HA ceramic scaffolds, so inducing an increase in the compression strength

  11. Fabrication and characterization of electrospun osteon mimicking scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Andric, T. [Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Sampson, A.C. [Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Freeman, J.W., E-mail: jwfreeman@vt.edu [Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

    2011-01-01

    Skeletal loss and bone deficiencies are a major worldwide problem with over 600,000 procedures performed in the US alone annually, making bone one of the most transplanted tissues, second to blood only. Bone is a composite tissue composed of organic matrix, inorganic bone mineral, and water. Structurally bone is organized into two distinct types: trabecular (or cancellous) and cortical (or compact) bones. Trabecular bone is characterized by an extensive interconnected network of pores. Cortical bone is composed of tightly packed units, called osteons, oriented parallel along to the axis of the bone. While the majority of scaffolds attempt to replicate the structure of the trabecular bone, fewer attempts have been made to create scaffolds to mimic the structure of cortical bone. The aim of this study was to develop a technique to fabricate scaffolds that mimic the organization of an osteon, the structural unit of cortical bone. We successfully built a rotating stage for PGA fibers and utilized it for collecting electrospun nanofibers and creating scaffolds. Resulting scaffolds consisted of concentric layers of electrospun PLLA or gelatin/PLLA nanofibers wrapped around PGA microfiber core with diameters that ranged from 200 to 600 {mu}m. Scaffolds were mineralized by incubation in 10x simulated body fluid, and scaffolds composed of 10%gelatin/PLLA had significantly higher amounts of calcium phosphate. The electrospun scaffolds also supported cellular attachment and proliferation of MC3T3 cells over the period of 28 days.

  12. Feasibility of autologous bone marrow mesenchymal stem cell-derived extracellular matrix scaffold for cartilage tissue engineering.

    Science.gov (United States)

    Tang, Cheng; Xu, Yan; Jin, Chengzhe; Min, Byoung-Hyun; Li, Zhiyong; Pei, Xuan; Wang, Liming

    2013-12-01

    Extracellular matrix (ECM) materials are widely used in cartilage tissue engineering. However, the current ECM materials are unsatisfactory for clinical practice as most of them are derived from allogenous or xenogenous tissue. This study was designed to develop a novel autologous ECM scaffold for cartilage tissue engineering. The autologous bone marrow mesenchymal stem cell-derived ECM (aBMSC-dECM) membrane was collected and fabricated into a three-dimensional porous scaffold via cross-linking and freeze-drying techniques. Articular chondrocytes were seeded into the aBMSC-dECM scaffold and atelocollagen scaffold, respectively. An in vitro culture and an in vivo implantation in nude mice model were performed to evaluate the influence on engineered cartilage. The current results showed that the aBMSC-dECM scaffold had a good microstructure and biocompatibility. After 4 weeks in vitro culture, the engineered cartilage in the aBMSC-dECM scaffold group formed thicker cartilage tissue with more homogeneous structure and higher expressions of cartilaginous gene and protein compared with the atelocollagen scaffold group. Furthermore, the engineered cartilage based on the aBMSC-dECM scaffold showed better cartilage formation in terms of volume and homogeneity, cartilage matrix content, and compressive modulus after 3 weeks in vivo implantation. These results indicated that the aBMSC-dECM scaffold could be a successful novel candidate scaffold for cartilage tissue engineering. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  13. Poly (L-lactic acid) porous scaffold-supported alginate hydrogel with improved mechanical properties and biocompatibility.

    Science.gov (United States)

    Chu, Jiaqi; Zeng, Shaodong; Gao, Liyang; Groth, Thomas; Li, Zhiwen; Kong, Junchao; Zhao, Mingyan; Li, Lihua

    2016-10-10

    Polymer porous scaffolds and hydrogels have been separately employed and explored for a wide range of applications including cell encapsulation, drug delivery, and tissue engineering. In this study, a three-dimensional poly (L-lactic acid) (PLLA) scaffold with interconnected and homogeneously distributed pores was fabricated to support the alginate hydrogel (Alg). The gels were filled into the porous scaffold, which acted as an analogue of native extracellular matrix (ECM) for entrapment of cells within a support of predefined shape. The mechanical strength of the composite scaffold was characterized by compression testing. The chondrocyte behavior in the scaffold was determined by inverted microscopy, scanning electron microscopy (SEM) and MTT viability assay. The repair efficiency of such a composite scaffold was further investigated in dog spinal defects by histological evaluation after implantation for 4 weeks. Results showed that the composite scaffold possessed superior mechanical properties and hierarchical porous structure in comparison to pure Alg. Cell culture revealed that the cells presented a specific cartilage status in the composite scaffold in line with higher adherence and proliferation ratio. The histological analyses suggested that the composite scaffold substantially promotes its integration in the host tissue accompanied with a low inflammatory reaction and new tissue formation. The method thus provides a useful pathway for scaffold preparation that can simultaneously achieve suitable mechanical properties and good biocompatibility.

  14. Physicochemical properties and enhanced cellullar responses of biocompatible polymeric scaffolds treated with atmospheric pressure plasma using O2 gas

    International Nuclear Information System (INIS)

    Lee, Hyun-Uk; Park, So-Young; Kang, Yoon-Hee; Jeong, Se-Young; Choi, Sae-Hae; Jahng, Yoon-Young; Chung, Gook-Hyun; Kim, Moon-Bum; Cho, Chae-Ryong

    2011-01-01

    Biocompatible polymeric scaffolds were fabricated by mixing 5 wt.% poly(ε-caprolactone) (P) with 4 wt.% gelatin (G) and 1.6 wt.% Dulbecco's modified Eagle's medium containing 10% fetal bovine serum (D). These PGD scaffolds were also treated with atmospheric pressure (AP) plasma using O 2 reactive gas (to create O-PGD scaffolds). The physicochemical and mechanical properties of the PGD scaffolds were characterized by in vitro biodegradability tests, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, contact angle measurements, and tensile strength measurements. The wettability and hydrophilic properties of the scaffold surface were improved remarkably by adding G and D to P, and by subsequent oxygen-assisted AP plasma treatment. An MTT assay, a cell attachment efficiency assay, scanning electron microscopy, and confocal microscopy revealed that Chinese Hamster Ovary (CHO)-K1 cells exhibited higher cell attachment and viability on the PGD and O-PGD scaffolds than on the P and PG scaffolds. Furthermore, the long-term viability of the CHO cells on the PGD and O-PGD scaffolds without exchanging the cell culture media was significantly improved compared to their viability on the P and PG scaffolds. Overall, the PGD and O-PGD scaffolds are expected to be useful as cell growth supporting biomaterials in tissue engineering.

  15. Bioactive glass-reinforced bioceramic ink writing scaffolds: sintering, microstructure and mechanical behavior.

    Science.gov (United States)

    Shao, Huifeng; Yang, Xianyan; He, Yong; Fu, Jianzhong; Liu, Limin; Ma, Liang; Zhang, Lei; Yang, Guojing; Gao, Changyou; Gou, Zhongru

    2015-09-10

    The densification of pore struts in bioceramic scaffolds is important for structure stability and strength reliability. An advantage of ceramic ink writing is the precise control over the microstructure and macroarchitecture. However, the use of organic binder in such ink writing process would heavily affect the densification of ceramic struts and sacrifice the mechanical strength of porous scaffolds after sintering. This study presents a low-melt-point bioactive glass (BG)-assisted sintering strategy to overcome the main limitations of direct ink writing (extrusion-based three-dimensional printing) and to produce high-strength calcium silicate (CSi) bioceramic scaffolds. The 1% BG-added CSi (CSi-BG1) scaffolds with rectangular pore morphology sintered at 1080 °C have a very small BG content, readily induce apatite formation, and show appreciable linear shrinkage (∼21%), which is consistent with the composite scaffolds with less or more BG contents sintered at either the same or a higher temperature. These CSi-BG1 scaffolds also possess a high elastic modulus (∼350 MPa) and appreciable compressive strength (∼48 MPa), and show significant strength enhancement after exposure to simulated body fluid-a performance markedly superior to those of pure CSi scaffolds. Particularly, the honeycomb-pore CSi-BG1 scaffolds show markedly higher compressive strength (∼88 MPa) than the scaffolds with rectangular, parallelogram, and Archimedean chord pore structures. It is suggested that this approach can potentially facilitate the translation of ceramic ink writing and BG-assisted sintering of bioceramic scaffold technologies to the in situ bone repair.

  16. [Experimental study of tissue engineered cartilage construction using oriented scaffold combined with bone marrow mesenchymal stem cells in vivo].

    Science.gov (United States)

    Duan, Wei; Da, Hu; Wang, Wentao; Lü, Shangjun; Xiong, Zhuo; Liu, Jian

    2013-05-01

    To investigate the feasibility of fabricating an oriented scaffold combined with chondrogenic-induced bone marrow mesenchymal stem cells (BMSCs) for enhancement of the biomechanical property of tissue engineered cartilage in vivo. Temperature gradient-guided thermal-induced phase separation was used to fabricate an oriented cartilage extracellular matrix-derived scaffold composed of microtubules arranged in parallel in vertical section. No-oriented scaffold was fabricated by simple freeze-drying. Mechanical property of oriented and non-oriented scaffold was determined by measurement of compressive modulus. Oriented and non-oriented scaffolds were seeded with chondrogenic-induced BMSCs, which were obtained from the New Zealand white rabbits. Proliferation, morphological characteristics, and the distribution of the cells on the scaffolds were analyzed by MTT assay and scanning electron microscope. Then cell-scaffold composites were implanted subcutaneously in the dorsa of nude mice. At 2 and 4 weeks after implantation, the samples were harvested for evaluating biochemical, histological, and biomechanical properties. The compressive modulus of oriented scaffold was significantly higher than that of non-oriented scaffold (t=201.099, P=0.000). The cell proliferation on the oriented scaffold was significantly higher than that on the non-oriented scaffold from 3 to 9 days (P fibers with chondrocyte-like cells on the oriented-structure constructs. Total DNA, glycosaminoglycan (GAG), and collagen contents increased with time, and no significant difference was found between 2 groups (P > 0.05). The compressive modulus of the oriented tissue engineered cartilage was significantly higher than that of the non-oriented tissue engineered cartilage at 2 and 4 weeks after implantation (P < 0.05). Total DNA, GAG, collagen contents, and compressive modulus in the 2 tissue engineered cartilages were significantly lower than those in normal cartilage (P < 0.05). Oriented extracellular

  17. Medicine for the wandering mind: mind wandering in medical practice.

    Science.gov (United States)

    Smallwood, Jonathan; Mrazek, Michael D; Schooler, Jonathan W

    2011-11-01

    Mind wandering--defined as a cognitive focus on information that is unrelated to immediate sensory input or the task at hand--is a ubiquitous characteristic of the human condition. When it occurs, the integrity of a wide range of cognitive skills can be compromised. The current paper describes the phenomenon of mind wandering, explores its potential role in medical practice and considers how the education system may profitably control this ubiquitous cognitive state. We argue that because many aspects of a medical professional's work (such as fatigue and depression) maximise the mind's tendency to wander, this experience is likely to be a common occurrence in many medical situations. We then review the psychological literature on mind wandering as it relates to medical practice. Based on this review, we suggest that because mind wandering interferes with an individual's ability to integrate current events into a more general context, its occurrence may lead to downstream problems in the way that symptoms are interpreted and treated. Finally, because the experience of mind wandering is often both difficult to control and hard to recognise, it is difficult to prevent. We argue that techniques that help individuals to become more mindful have the potential to ameliorate the cost of mind wandering to the medical profession. Given the ubiquitous nature of the experience of mind wandering, the integration of mindfulness training into medical education programmes could be of general benefit to society at large. © Blackwell Publishing Ltd 2011.

  18. A practice scaffolding interactive platform

    DEFF Research Database (Denmark)

    Bundsgaard, Jeppe

    2009-01-01

    A Practice Scaffolding Interactive Platform (PracSIP) is a social learning platform which supports students in collaborative project based learning by simulating a professional practice. A PracSIP puts the core tools of the simulated practice at the students' disposal, it organizes collaboration...

  19. Problem Solving, Scaffolding and Learning

    Science.gov (United States)

    Lin, Shih-Yin

    2012-01-01

    Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…

  20. Coating of hydrophobins on three-dimensional electrospun poly(lactic-co-glycolic acid) scaffolds for cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Hou Sen; Li Xinxin; Li Xiaoyu; Feng Xizeng, E-mail: xzfeng@nankai.edu.c [College of Life Science, Nankai University, Weijin Road 94, Tianjin, 300071 (China)

    2009-09-15

    Surface modification with hydrophobins is very important for cell adhesion in its applications in biosensor fabrication. In this study, we modified the surface of three-dimensional electrospun poly(lactide-co-glycolide) (PLGA) scaffolds with hydrophobin HFBI and collagen, and investigated its applications for cell adhesion. We found that HFBI could not only improve the hydrophilicity of the three-dimensional electrospun PLGA scaffolds but also endow the electrospun PLGA scaffolds with water permeability. This permeability should be attributed to both the hydrophilicity of the modified PLGA surface and the large positive capillary effect induced by the microstructures. Further experiment indicated that HFBI modification could improve collagen immobilization on the electrospun PLGA scaffolds and the HFBI/collagen modified electrospun PLGA scaffolds showed higher efficiency in promoting cell adhesion than the native PLGA scaffolds. This finding should be of potential application in biosensor device fabrication.

  1. Metaphilosophy of Mind: how Do Minds Investigate Minds? Refutation of the Theocentric View

    OpenAIRE

    Werner, Konrad

    2016-01-01

    I shall propose metaphilosophy of mind as the philosophy of mind investigating mind. That is to say, I pose the question of how knowledge of mind provided by cognitive science, broadly construed, is constrained by the epistemic position of the knower, i.e. by the very fact that it is undertaken by a mind. Here I would like to propose a minimal framework, based on two distinctions: (i) the standard one between empirical and conceptual analysis; (ii) a new one, between the internal questions of...

  2. Biocompatibility of two experimental scaffolds for regenerative endodontics

    Directory of Open Access Journals (Sweden)

    Dephne Jack Xin Leong

    2016-05-01

    Full Text Available Objectives The biocompatibility of two experimental scaffolds for potential use in revascularization or pulp regeneration was evaluated. Materials and Methods One resilient lyophilized collagen scaffold (COLL, releasing metronidazole and clindamycin, was compared to an experimental injectable poly(lactic-co-glycolic acid scaffold (PLGA, releasing clindamycin. Human dental pulp stem cells (hDPSCs were seeded at densities of 1.0 × 104, 2.5 × 104, and 5.0 × 104. The cells were investigated by light microscopy (cell morphology, MTT assay (cell proliferation and a cytokine (IL-8 ELISA test (biocompatibility. Results Under microscope, the morphology of cells coincubated for 7 days with the scaffolds appeared healthy with COLL. Cells in contact with PLGA showed signs of degeneration and apoptosis. MTT assay showed that at 5.0 × 104 hDPSCs, COLL demonstrated significantly higher cell proliferation rates than cells in media only (control, p < 0.01 or cells co-incubated with PLGA (p < 0.01. In ELISA test, no significant differences were observed between cells with media only and COLL at 1, 3, and 6 days. Cells incubated with PLGA expressed significantly higher IL-8 than the control at all time points (p < 0.01 and compared to COLL after 1 and 3 days (p < 0.01. Conclusions The COLL showed superior biocompatibility and thus may be suitable for endodontic regeneration purposes.

  3. Nanorod mediated collagen scaffolds as extra cellular matrix mimics

    International Nuclear Information System (INIS)

    Vedhanayagam, Mohan; Nair, Balachandran Unni; Sreeram, Kalarical Janardhanan; Mohan, Ranganathan

    2015-01-01

    Creating collagen scaffolds that mimic extracellular matrices without using toxic exogenous materials remains a big challenge. A new strategy to create scaffolds through end-to-end crosslinking through functionalized nanorods leading to well-designed architecture is presented here. Self-assembled scaffolds with a denaturation temperature of 110 °C, porosity of 70%, pore size of 0.32 μm and Young’s modulus of 231 MPa were developed largely driven by imine bonding between 3-mercapto-1-propanal (MPA) functionalized ZnO nanorods and collagen. The mechanical properties obtained were much higher than that of native collagen, collagen—MPA, collagen—3-mercapto-1-propanol (3MPOH) or collagen- 3-MPOH-ZnO, clearly bringing out the relevance of nanorod mediated assembly of fibrous networks. This new strategy has led to scaffolds with mechanical properties much higher than earlier reports and can provide support for cell growth and facilitation of cell attachment. (paper)

  4. The hooligan's mind.

    Science.gov (United States)

    Maniglio, Roberto

    2007-01-01

    Football hooliganism is a world phenomenon and an everyday matter. Society spends a lot of money to prevent and control it. We need to know what hooligans think in order to anticipate their actions and prevent their violent behaviors. In this paper, I propose a theory of the hooligan's conscious mind, by analyzing the thinking of a real Italian hooligan who was my patient. I will show that violent behaviors of hooligans are not unconscious, because the mental states (both beliefs and goals) of hooligans are explicitly represented in their mind. In contrast, I will suggest that both supporting and fighting are planned (i.e., goal directed), because "recognized supremacy" is explicitly represented as the ultimate goal. In fact, hooligans support and fight in order to be recognized as good hooligans, i.e. as good supporters as well as good fighters.

  5. The distracted mind on the wheel: Overall propensity to mind wandering is associated with road crash responsibility.

    Science.gov (United States)

    Gil-Jardiné, Cédric; Née, Mélanie; Lagarde, Emmanuel; Schooler, Jonathan; Contrand, Benjamin; Orriols, Ludivine; Galera, Cédric

    2017-01-01

    The role of distractions on attentional lapses that place road users in higher risk of crash remains poorly understood. We aimed to assess the respective impact of (i) mind wandering trait (propensity to mind wander in the everyday life as measured with a set of 4 questions on the proportion of time spent mind wandering in 4 different situations) and (ii) mind wandering state (disturbing thoughts just before the crash) on road crash risk using a comparison between responsible and non-responsible drivers. 954 drivers injured in a road crash were interviewed at the adult emergency department of the Bordeaux university hospital in France (2013-2015). Responsibility for the crash, mind wandering (trait/state), external distraction, alcohol use, psychotropic drug use, and sleep deprivation were evaluated. Based on questionnaire reports, 39% of respondents were classified with a mind wandering trait and 13% reported a disturbing thought just before the crash. While strongly correlated, mind wandering state and trait were independently associated with responsibility for a traffic crash (State: OR = 2.51, 95% CI: 1.64-3.83 and Trait: OR = 1.62, 95% CI: 1.22-2.16 respectively). Self-report of distracting thoughts therefore did not capture the entire risk associated with the propensity of the mind to wander, either because of under-reported thoughts and/or other deleterious mechanisms to be further explored.

  6. The distracted mind on the wheel: Overall propensity to mind wandering is associated with road crash responsibility.

    Directory of Open Access Journals (Sweden)

    Cédric Gil-Jardiné

    Full Text Available The role of distractions on attentional lapses that place road users in higher risk of crash remains poorly understood. We aimed to assess the respective impact of (i mind wandering trait (propensity to mind wander in the everyday life as measured with a set of 4 questions on the proportion of time spent mind wandering in 4 different situations and (ii mind wandering state (disturbing thoughts just before the crash on road crash risk using a comparison between responsible and non-responsible drivers. 954 drivers injured in a road crash were interviewed at the adult emergency department of the Bordeaux university hospital in France (2013-2015. Responsibility for the crash, mind wandering (trait/state, external distraction, alcohol use, psychotropic drug use, and sleep deprivation were evaluated. Based on questionnaire reports, 39% of respondents were classified with a mind wandering trait and 13% reported a disturbing thought just before the crash. While strongly correlated, mind wandering state and trait were independently associated with responsibility for a traffic crash (State: OR = 2.51, 95% CI: 1.64-3.83 and Trait: OR = 1.62, 95% CI: 1.22-2.16 respectively. Self-report of distracting thoughts therefore did not capture the entire risk associated with the propensity of the mind to wander, either because of under-reported thoughts and/or other deleterious mechanisms to be further explored.

  7. The dialogically extended mind

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Gangopadhyay, Nivedita; Tylén, Kristian

    2014-01-01

    A growing conceptual and empirical literature is advancing the idea that language extends our cognitive skills. One of the most influential positions holds that language – qua material symbols – facilitates individual thought processes by virtue of its material properties. Extending upon this model...... relate our approach to other ideas about collective minds and review a number of empirical studies to identify the mechanisms enabling the constitution of interpersonal cognitive systems....

  8. Chitin Scaffolds in Tissue Engineering

    Science.gov (United States)

    Jayakumar, Rangasamy; Chennazhi, Krishna Prasad; Srinivasan, Sowmya; Nair, Shantikumar V.; Furuike, Tetsuya; Tamura, Hiroshi

    2011-01-01

    Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine. PMID:21673928

  9. Mind, Thinking and Creativity

    Directory of Open Access Journals (Sweden)

    Janani Harish

    2016-05-01

    Full Text Available Global civilization is the product of diverse cultures, each contributing a unique perspective arising from the development of different mental faculties and powers of mind. The momentous achievements of modern science are the result of the cumulative development of mind’s capacity for analytic thinking, mathematical rendering and experimental validation. The near-exclusive preoccupation with analysis, universal laws, mechanism, materialism, and objective experience over the past two centuries has shaped the world we live in today, accounting both for its accomplishments and its insoluble problems. Today humanity confronts complex challenges that defy solution by piecemeal analysis, unidimensional theories, and fragmented strategies. Poverty, unemployment, economic crisis, fundamentalism, violence, climate change, war, refugees, reflect the limitations and blindspots that have resulted from a partial, one-sided application of the diverse capacities of the human mind. Human monocultures suffer from all the limitations as their biological counterparts. There is urgent need to revive the legitimacy of synthetic, organic and integrated modes of thinking, to restore the credibility of subjective self-experience in science, to reaffirm the place of symbol, analogy and metaphor as valid ways of knowing and communication in education, to recognize the unique role of the individual in social processes, to recognize the central role of insight and intuition in science as in art. This article examines themes presented at the WAAS-WUC course on Mind, Thinking and Creativity, conducted at Dubrovnik in April 2016.

  10. Introduction: Minds, Bodies, Machines

    Directory of Open Access Journals (Sweden)

    Deirdre Coleman

    2008-10-01

    Full Text Available This issue of 19 brings together a selection of essays from an interdisciplinary conference on 'Minds, Bodies, Machines' convened last year by Birkbeck's Centre for Nineteenth-Century Studies, University of London, in partnership with the English programme, University of Melbourne and software developers Constraint Technologies International (CTI. The conference explored the relationship between minds, bodies and machines in the long nineteenth century, with a view to understanding the history of our technology-driven, post-human visions. It is in the nineteenth century that the relationship between the human and the machine under post-industrial capitalism becomes a pervasive theme. From Blake on the mills of the mind by which we are enslaved, to Carlyle's and Arnold's denunciation of the machinery of modern life, from Dickens's sooty fictional locomotive Mr Pancks, who 'snorted and sniffed and puffed and blew, like a little labouring steam-engine', and 'shot out […]cinders of principles, as if it were done by mechanical revolvency', to the alienated historical body of the late-nineteenth-century factory worker under Taylorization, whose movements and gestures were timed, regulated and rationalised to maximize efficiency; we find a cultural preoccupation with the mechanisation of the nineteenth-century human body that uncannily resonates with modern dreams and anxieties around technologies of the human.

  11. In vitro study on the degradation of lithium-doped hydroxyapatite for bone tissue engineering scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yaping; Yang, Xu; Gu, Zhipeng; Qin, Huanhuan [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Li, Li [Department of Oncology, The 452 Hospital of Chinese PLA, Chengdu, Sichuan Province 610021 (China); Liu, Jingwang [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Yu, Xixun, E-mail: yuxixun@163.com [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China)

    2016-09-01

    HA scaffolds. - Highlights: • A bone-like apatite layer with bioactivity was formed on the surfaces of LiHA scaffolds. • LiHA scaffolds showed a higher degradation trend than pure HA scaffolds in osteoblast-mediated degradation in vitro. • LiHA scaffolds were beneficial to the proliferation of osteoblasts.

  12. Poly(hydroxybutyrate)/cellulose acetate blend nanofiber scaffolds: Preparation, characterization and cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Zhijiang, Cai, E-mail: caizhijiang@hotmail.com [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); State Key Laboratory of Hollow Fiber Membrane Material and Processes, No 399 BingShuiXi Street, XiQing District, Tianjin, China, 300387 (China); Yi, Xu; Haizheng, Yang; Jia, Jianru; Liu, Yuanpei [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China)

    2016-01-01

    Poly(hydroxybutyrate) (PHB)/cellulose acetate (CA) blend nanofiber scaffolds were fabricated by electrospinning using the blends of chloroform and DMF as solvent. The blend nanofiber scaffolds were characterized by SEM, FTIR, XRD, DSC, contact angle and tensile test. The blend nanofibers exhibited cylindrical, uniform, bead-free and random orientation with the diameter ranged from 80–680 nm. The scaffolds had very well interconnected porous fibrous network structure and large aspect surface areas. It was found that the presence of CA affected the crystallization of PHB due to formation of intermolecular hydrogen bonds, which restricted the preferential orientation of PHB molecules. The DSC result showed that the PHB and CA were miscible in the blend nanofiber. An increase in the glass transition temperature was observed with increasing CA content. Additionally, the mechanical properties of blend nanofiber scaffolds were largely influenced by the weight ratio of PHB/CA. The tensile strength, yield strength and elongation at break of the blend nanofiber scaffolds increased from 3.3 ± 0.35 MPa, 2.8 ± 0.26 MPa, and 8 ± 0.77% to 5.05 ± 0.52 MPa, 4.6 ± 0.82 MPa, and 17.6 ± 1.24% by increasing PHB content from 60% to 90%, respectively. The water contact angle of blend nanofiber scaffolds decreased about 50% from 112 ± 2.1° to 60 ± 0.75°. The biodegradability was evaluated by in vitro degradation test and the results revealed that the blend nanofiber scaffolds showed much higher degradation rates than the neat PHB. The cytocompatibility of the blend nanofiber scaffolds was preliminarily evaluated by cell adhesion studies. The cells incubated with PHB/CA blend nanofiber scaffold for 48 h were capable of forming cell adhesion and proliferation. It showed much better biocompatibility than pure PHB film. Thus, the prepared PHB/CA blend nanofiber scaffolds are bioactive and may be more suitable for cell proliferation suggesting that these scaffolds can be used for

  13. Fabrication, characterization and in vitro drug release behavior of electrospun PLGA/chitosan nanofibrous scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Z.X.; Zheng, W.; Li, L. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Zheng, Y.F., E-mail: yfzheng@pku.edu.cn [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China)

    2011-02-15

    Graphical abstract: The fenbufen loaded PLGA/chitosan nanofibrous scaffolds were fabricated by electrospinning. The hydrophilicity of nanofibrous scaffold was enhanced with the increase of chitosan content. The drug release also is accelerated with chitosan increasing because the higher hydrophilicity makes drug diffusing from scaffold more easily. Research highlights: {yields} The average diameter increased with the increase of chitosan content and then decreased. {yields} The release rate of fenbufen increased with the increase of chitosan. {yields} The aligned nanofibrous scaffold exhibits lower drug release rate. {yields} The drug release could be controlled by crosslinking in glutaraldehyde vapor. - Abstract: In this study both aligned and randomly oriented poly(D,L-lactide-co-glycolide) (PLGA)/chitosan nanofibrous scaffold have been prepared by electrospinning. The ratio of PLGA to chitosan was adjusted to get smooth nanofiber surface. Morphological characterization using scanning electron microscopy showed that the aligned nanofiber diameter distribution obtained by electrospinning of polymer blend increased with the increase of chitosan content which was similar to that of randomly oriented nanofibers. The release characteristic of model drug fenbufen (FBF) from the FBF-loaded aligned and randomly oriented PLGA and PLGA/chitosan nanofibrous scaffolds was investigated. The drug release rate increased with the increase of chitosan content because the addition of chitosan enhanced the hydrophilicity of the PLGA/chitosan composite scaffold. Moreover, for the aligned PLGA/chitosan nanofibrous scaffold the release rate was lower than that of randomly oriented PLGA/chitosan nanofibrous scaffold, which indicated that the nanofiber arrangement would influence the release behavior. In addition, crosslinking in glutaraldehyde vapor would decrease the burst release of FBF from FBF-loaded PLGA/chitosan nanofibrous scaffold with a PLGA/chitosan ratio less than 9/1, which

  14. Surface-modified functionalized polycaprolactone scaffolds for bone repair: in vitro and in vivo experiments.

    Science.gov (United States)

    Jensen, Jonas; Rölfing, Jan Hendrik Duedal; Le, Dang Quang Svend; Kristiansen, Asger Albaek; Nygaard, Jens Vinge; Hokland, Lea Bjerre; Bendtsen, Michael; Kassem, Moustapha; Lysdahl, Helle; Bünger, Cody Eric

    2014-09-01

    A porcine calvaria defect study was carried out to investigate the bone repair potential of three-dimensional (3D)-printed poly-ε-caprolactone (PCL) scaffolds embedded with nanoporous PCL. A microscopic grid network was created by rapid prototyping making a 3D-fused deposition model (FDM-PCL). Afterward, the FDM-PCL scaffolds were infused with a mixture of PCL, water, and 1,4-dioxane and underwent a thermal-induced phase separation (TIPS) followed by lyophilization. The TIPS process lead to a nanoporous structure shielded by the printed microstructure (NSP-PCL). Sixteen Landrace pigs were divided into two groups with 8 and 12 weeks follow-up, respectively. A total of six nonpenetrating holes were drilled in the calvaria of each animal. The size of the cylindrical defects was h 10 mm and Ø 10 mm. The defects were distributed randomly using following groups: (a) NSP-PCL scaffold, (b) FDM-PCL scaffold, (c) autograft, (d) empty defect, (a1) NSP-PCL scaffold + autologous mononuclear cells, and (a2) NSP-PCL scaffold + bone morphogenetic protein 2. Bone volume to total volume was analyzed using microcomputed tomography (µCT) and histomorphometry. The µCT and histological data showed significantly less bone formation in the NSP-PCL scaffolds in all three variations after both 8 and 12 weeks compared to all other groups. The positive autograft control had significantly higher new bone formation compared to all other groups except the FDM-PCL when analyzed using histomorphometry. The NSP-PCL scaffolds were heavily infiltrated with foreign body giant cells suggesting an inflammatory response and perhaps active resorption of the scaffold material. The unmodified FDM-PCL scaffold showed good osteoconductivity and osseointegration after both 8 and 12 weeks. © 2013 Wiley Periodicals, Inc.

  15. Fabrication, characterization and in vitro drug release behavior of electrospun PLGA/chitosan nanofibrous scaffold

    International Nuclear Information System (INIS)

    Meng, Z.X.; Zheng, W.; Li, L.; Zheng, Y.F.

    2011-01-01

    Graphical abstract: The fenbufen loaded PLGA/chitosan nanofibrous scaffolds were fabricated by electrospinning. The hydrophilicity of nanofibrous scaffold was enhanced with the increase of chitosan content. The drug release also is accelerated with chitosan increasing because the higher hydrophilicity makes drug diffusing from scaffold more easily. Research highlights: → The average diameter increased with the increase of chitosan content and then decreased. → The release rate of fenbufen increased with the increase of chitosan. → The aligned nanofibrous scaffold exhibits lower drug release rate. → The drug release could be controlled by crosslinking in glutaraldehyde vapor. - Abstract: In this study both aligned and randomly oriented poly(D,L-lactide-co-glycolide) (PLGA)/chitosan nanofibrous scaffold have been prepared by electrospinning. The ratio of PLGA to chitosan was adjusted to get smooth nanofiber surface. Morphological characterization using scanning electron microscopy showed that the aligned nanofiber diameter distribution obtained by electrospinning of polymer blend increased with the increase of chitosan content which was similar to that of randomly oriented nanofibers. The release characteristic of model drug fenbufen (FBF) from the FBF-loaded aligned and randomly oriented PLGA and PLGA/chitosan nanofibrous scaffolds was investigated. The drug release rate increased with the increase of chitosan content because the addition of chitosan enhanced the hydrophilicity of the PLGA/chitosan composite scaffold. Moreover, for the aligned PLGA/chitosan nanofibrous scaffold the release rate was lower than that of randomly oriented PLGA/chitosan nanofibrous scaffold, which indicated that the nanofiber arrangement would influence the release behavior. In addition, crosslinking in glutaraldehyde vapor would decrease the burst release of FBF from FBF-loaded PLGA/chitosan nanofibrous scaffold with a PLGA/chitosan ratio less than 9/1, which would be beneficial

  16. Combining technologies to create bioactive hybrid scaffolds for bone tissue engineering.

    Science.gov (United States)

    Nandakumar, Anandkumar; Barradas, Ana; de Boer, Jan; Moroni, Lorenzo; van Blitterswijk, Clemens; Habibovic, Pamela

    2013-01-01

    Combining technologies to engineer scaffolds that can offer physical and chemical cues to cells is an attractive approach in tissue engineering and regenerative medicine. In this study, we have fabricated polymer-ceramic hybrid scaffolds for bone regeneration by combining rapid prototyping (RP), electrospinning (ESP) and a biomimetic coating method in order to provide mechanical support and a physico-chemical environment mimicking both the organic and inorganic phases of bone extracellular matrix (ECM). Poly(ethylene oxide terephthalate)-poly(buthylene terephthalate) (PEOT/PBT) block copolymer was used to produce three dimensional scaffolds by combining 3D fiber (3DF) deposition, and ESP, and these constructs were then coated with a Ca-P layer in a simulated physiological solution. Scaffold morphology and composition were studied using scanning electron microscopy (SEM) coupled to energy dispersive X-ray analyzer (EDX) and Fourier Tranform Infrared Spectroscopy (FTIR). Bone marrow derived human mesenchymal stromal cells (hMSCs) were cultured on coated and uncoated 3DF and 3DF + ESP scaffolds for up to 21 d in basic and mineralization medium and cell attachment, proliferation, and expression of genes related to osteogenesis were assessed. Cells attached, proliferated and secreted ECM on all the scaffolds. There were no significant differences in metabolic activity among the different groups on days 7 and 21. Coated 3DF scaffolds showed a significantly higher DNA amount in basic medium at 21 d compared with the coated 3DF + ESP scaffolds, whereas in mineralization medium, the presence of coating in 3DF+ESP scaffolds led to a significant decrease in the amount of DNA. An effect of combining different scaffolding technologies and material types on expression of a number of osteogenic markers (cbfa1, BMP-2, OP, OC and ON) was observed, suggesting the potential use of this approach in bone tissue engineering.

  17. Fabrication and characterization of hydrothermal cross-linked chitosan porous scaffolds for cartilage tissue engineering applications.

    Science.gov (United States)

    Shamekhi, Mohammad Amin; Rabiee, Ahmad; Mirzadeh, Hamid; Mahdavi, Hamid; Mohebbi-Kalhori, Davod; Baghaban Eslaminejad, Mohamadreza

    2017-11-01

    The use of various chemical cross-linking agents for the improvement of scaffolds physical and mechanical properties is a common practical method, which is limited by cytotoxicity effects. Due to exerting contract type forces, chondrocytes are known to implement shrinkage on the tissue engineered constructs, which can be avoided by the scaffold cross-linking. In the this research, chitosan scaffolds are cross-linked with hydrothermal treatment with autoclave sterilization time of 0, 10, 20 and 30min, to avoid the application of the traditional chemical toxic materials. The optimization studies with gel content and crosslink density measurements indicate that for 20min sterilization time, the gel content approaches to ~80%. The scaffolds are fully characterized by the conventional techniques such as SEM, porosity and permeability, XRD, compression, thermal analysis and dynamic mechanical thermal analysis (DMTA). FT-IR studies shows that autoclave inter-chain cross-linking reduces the amine group absorption at 1560cm -1 and increase the absorption of N-acetylated groups at 1629cm -1 . It is anticipated, that this observation evidenced by chitosan scaffold browning upon autoclave cross-linking is an indication of the familiar maillard reaction between amine moieties and carbonyl groups. The biodegradation rate analysis shows that chitosan scaffolds with lower concentrations, possess suitable degradation rate for cartilage tissue engineering applications. In addition, cytotoxicity analysis shows that fabricated scaffolds are biocompatible. The human articular chondrocytes seeding into 3D cross-linked scaffolds shows a higher viability and proliferation in comparison with the uncross-linked samples and 2D controls. Investigation of cell morphology on the scaffolds by SEM, shows a more spherical morphology of chondrocytes on the cross-linked scaffolds for 21days of in vitro culture. Copyright © 2017. Published by Elsevier B.V.

  18. Toward a Framework on How Affordances and Motives Can Drive Different Uses of Scaffolds: Theory, Evidence, and Design Implications

    Science.gov (United States)

    Belland, Brian R.; Drake, Joel

    2013-01-01

    One way to help students engage in higher-order thinking is through scaffolding, which can be defined as support that allows students to participate meaningfully in and gain skill at a task that is beyond their unassisted abilities. Most research on computer-based scaffolds assesses the average impact of the tools on learning outcomes. This is…

  19. Psycho-physiologic emergentism; four minds in a body

    Directory of Open Access Journals (Sweden)

    David L. Rowland

    2017-10-01

    Full Text Available The mind-body problem represents one of the most debated topics in the neurosciences. From a psychological standpoint, abstract/non-material data are an intrinsic part of the mind, intervening to a large extent in reasoning and decision making processes. Imaging studies also show a strong correlation between higher cognitive functions (such as working memory and specific cerebral brain regions (a fronto-parietal network of interacting left and right brain areas. In contrast, the physical/material brain would be unable to interact with abstract-immaterial data, such that the psychological processing of abstract data (processes such as thinking, reasoning, and judgment is attributed to the mind, with the mind representing a distinct entity interposed between the brain and abstract-immaterial data. Recent data suggest that the mind-body problem may simply be an artifact of human experience/ understanding, as the brain actually represents actually an intrinsic part of the mind. Even if the physical brain is not able to interact with abstract mental data, the brain still could process abstract data through a dynamic association between the abstract data and cerebral stimuli/ impulses. This form of processing without interaction defines the mind as a complex neurobiological structure, with the unconscious part of the mind processing abstract-immaterial data in a conscious/ mental format. In this overview, important concepts of psycho-physiologic emergentism, including internal mental reality, internal mental existence, internal mental interaction, and structural and informational dichotomies of the brain, are iterated. Such concepts/properties represent a neuro-informational support system capable of generating four distinct minds within the single brain. Future studies should further develop the dynamic and immaterial-material nature of the mind, as a possible premise for a scientific definition and understanding of mental events like affectivity

  20. PENERAPAN METODE MIND MAPPING PADA PEMBELAJARAN MATEMATIKA

    Directory of Open Access Journals (Sweden)

    Rahma Faelasofi

    2016-09-01

    Full Text Available The objectives of this research was to solve how to increase students learning mathematic achievments on the subject of statistic. This study aims to determine whether the students learning mathematic achievments of the student SMP Muhammadiyah 1 Gadingrejo in the academic year of 2014-2015 using learning method mind mapping on the subject of statistics can be higher than the students’ learning mathematic achievments without using learning method mind mapping. This research is a quantitative approach. The population was all of the students in first grade of the SMP Muhammadiyah 1 Gadingrejo in the academic year of 2014- 2015. The samples of the research were taken by using the cluster random sampling technique. Based on hypothesis test, it can be included that there are differences in the average student learning achievments between using learning method mind mapping and learning method lecture on the subject of Statistics of the student in first grade of the SMP Muhammadiyah 1 Gadingrejo in the academic year of 2014-2015. Keywords: learning method mind mapping, students’ learning mathematic achievments

  1. Addition of selenium nanoparticles to electrospun silk scaffolds improves mammalian cell activity while reducing bacterial growth

    Directory of Open Access Journals (Sweden)

    Stanley Chung

    2016-07-01

    Full Text Available Silk possesses many beneficial wound healing properties, and electrospun scaffolds are especially applicable for skin applications, due to their smaller interstices and higher surface areas compared to non-electrospun equivalents. However, purified silk promotes microbial growth. In contrast, selenium nanoparticles have excellent antibacterial properties and are a novel antimicrobial chemistry. Here, electrospun silk scaffolds were doped with selenium nanoparticles to impart antibacterial properties to the silk scaffolds. Results showed significantly improved bacterial inhibition and improvement in human dermal fibroblast metabolic activity. These results suggest that the addition of selenium nanoparticles to electrospun silk is a promising approach to improve wound healing with reduced infection, without relying on antibiotics.

  2. Bioactive polymeric scaffolds for tissue engineering

    Directory of Open Access Journals (Sweden)

    Scott Stratton

    2016-12-01

    Full Text Available A variety of engineered scaffolds have been created for tissue engineering using polymers, ceramics and their composites. Biomimicry has been adopted for majority of the three-dimensional (3D scaffold design both in terms of physicochemical properties, as well as bioactivity for superior tissue regeneration. Scaffolds fabricated via salt leaching, particle sintering, hydrogels and lithography have been successful in promoting cell growth in vitro and tissue regeneration in vivo. Scaffold systems derived from decellularization of whole organs or tissues has been popular due to their assured biocompatibility and bioactivity. Traditional scaffold fabrication techniques often failed to create intricate structures with greater resolution, not reproducible and involved multiple steps. The 3D printing technology overcome several limitations of the traditional techniques and made it easier to adopt several thermoplastics and hydrogels to create micro-nanostructured scaffolds and devices for tissue engineering and drug delivery. This review highlights scaffold fabrication methodologies with a focus on optimizing scaffold performance through the matrix pores, bioactivity and degradation rate to enable tissue regeneration. Review highlights few examples of bioactive scaffold mediated nerve, muscle, tendon/ligament and bone regeneration. Regardless of the efforts required for optimization, a shift in 3D scaffold uses from the laboratory into everyday life is expected in the near future as some of the methods discussed in this review become more streamlined.

  3. Alginate based scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Valente, J.F.A.; Valente, T.A.M. [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Faculdade de Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal); Alves, P.; Ferreira, P. [CIEPQPF, Departamento de Engenharia Quimica, Universidade de Coimbra, Polo II, Pinhal de Marrocos, 3030-290 Coimbra (Portugal); Silva, A. [Centro de Ciencia e Tecnologia Aeroespaciais, Universidade da Beira Interior, Covilha (Portugal); Correia, I.J., E-mail: icorreia@ubi.pt [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Faculdade de Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal)

    2012-12-01

    The design and production of scaffolds for bone tissue regeneration is yet unable to completely reproduce the native bone properties. In the present study new alginate microparticle and microfiber aggregated scaffolds were produced to be applied in this area of regenerative medicine. The scaffolds' mechanical properties were characterized by thermo mechanical assays. Their morphological characteristics were evaluated by isothermal nitrogen adsorption and scanning electron microscopy. The density of both types of scaffolds was determined by helium pycnometry and mercury intrusion porosimetry. Furthermore, scaffolds' cytotoxic profiles were evaluated in vitro by seeding human osteoblast cells in their presence. The results obtained showed that scaffolds have good mechanical and morphological properties compatible with their application as bone substitutes. Moreover, scaffold's biocompatibility was confirmed by the observation of cell adhesion and proliferation after 5 days of being seeded in their presence and by non-radioactive assays. - Highlights: Black-Right-Pointing-Pointer Design and production of scaffolds for bone tissue regeneration. Black-Right-Pointing-Pointer Microparticle and microfiber alginate scaffolds were produced through a particle aggregation technique; Black-Right-Pointing-Pointer Scaffolds' mechanically and biologically properties were characterized through in vitro studies;.

  4. Mindfulness in occupational therapy education.

    Science.gov (United States)

    Gura, Shira Taylor

    2010-07-01

    ABSTRACT The purpose of this paper is to explore the value of mindfulness and its role in occupational therapy education. The plethora of research on mindfulness-based stress reduction programs has shown consistent and positive results to enhance quality of life in clinical and nonclinical populations. Offering students the opportunities to learn and experience mindfulness could lead to enhanced self-awareness and care, focus and empathy, and a decrease of client judgment enhancing the success of clinical interventions.

  5. It Takes Two to Tango: Towards Theory of AI's Mind

    OpenAIRE

    Chandrasekaran, Arjun; Yadav, Deshraj; Chattopadhyay, Prithvijit; Prabhu, Viraj; Parikh, Devi

    2017-01-01

    Theory of Mind is the ability to attribute mental states (beliefs, intents, knowledge, perspectives, etc.) to others and recognize that these mental states may differ from one's own. Theory of Mind is critical to effective communication and to teams demonstrating higher collective performance. To effectively leverage the progress in Artificial Intelligence (AI) to make our lives more productive, it is important for humans and AI to work well together in a team. Traditionally, there has been m...

  6. Ceramic Identity Contributes to Mechanical Properties and Osteoblast Behavior on Macroporous Composite Scaffolds

    Directory of Open Access Journals (Sweden)

    J. Kent Leach

    2012-05-01

    Full Text Available Implants formed of metals, bioceramics, or polymers may provide an alternative to autografts for treating large bone defects. However, limitations to each material motivate the examination of composites to capitalize on the beneficial aspects of individual components and to address the need for conferring bioactive behavior to the polymer matrix. We hypothesized that the inclusion of different bioceramics in a ceramic-polymer composite would alter the physical properties of the implant and the cellular osteogenic response. To test this, composite scaffolds formed from poly(lactide-co-glycolide (PLG and either hydroxyapatite (HA, β-tricalcium phosphate (TCP, or bioactive glass (Bioglass 45S®, BG were fabricated, and the physical properties of each scaffold were examined. We quantified cell proliferation by DNA content, osteogenic response of human osteoblasts (NHOsts to composite scaffolds by alkaline phosphatase (ALP activity, and changes in gene expression by qPCR. Compared to BG-PLG scaffolds, HA-PLG and TCP-PLG composite scaffolds possessed greater compressive moduli. NHOsts on BG-PLG substrates exhibited higher ALP activity than those on control, HA-, or TCP-PLG scaffolds after 21 days, and cells on composites exhibited a 3-fold increase in ALP activity between 7 and 21 days versus a minimal increase on control scaffolds. Compared to cells on PLG controls, RUNX2 expression in NHOsts on composite scaffolds was lower at both 7 and 21 days, while expression of genes encoding for bone matrix proteins (COL1A1 and SPARC was higher on BG-PLG scaffolds at both time points. These data demonstrate the importance of selecting a ceramic when fabricating composites applied for bone healing.

  7. 8 Questions About the Conscious Mind

    NARCIS (Netherlands)

    Dooremalen, A.J.P.W.

    Can the mind function separately from the brain? Can machines have conscious minds? Is Google Maps part of the conscious mind? Hans Dooremalen provides answers to these three and five other questions about the conscious mind in an easy to read introduction to the philosophy of mind.

  8. Mindful parenting in mental health care

    NARCIS (Netherlands)

    Bogels, S.M.; Lehtonen, A.; Restifo, K.

    2010-01-01

    Mindfulness is a form of meditation based on the Buddhist tradition, which has been used over the last two decades to successfully treat a multitude of mental health problems. Bringing mindfulness into parenting ("mindful parenting") is one of the applications of mindfulness. Mindful parenting

  9. The Bisphosphonate Clodronate Modifying Hydroxyapatite Bioceramics for Bone Scaffold

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To investigate the efficiency of clodronate modifying HA bioceramics , and to evaluate the effect of clodronate modifying HA bioceramies on the cells in vitro, clodronate modified the porous HA bioceramics for bone scaffold by chelation. The outermost layer of the specimens was analyzed by XPS and FI- IR. The depth profile was investigated by the argon-ion sputtering method. The cell culture test was conducted using MC3 T3-E1 osteoblastic cells. The cells were inoculated and cultured on the scaffolds. Morphological observation of the cells,MTT test and ALP activity test evaluated the cell attachment, proliferation and activity on the materials. Characteristic peaks in XPS and FT-IR spectra indicated clodronate being immobilized on the surface of the bioceramics.The cell culture test in cell quantity and morphology indicated active proliferation of the cells on the scaffolds. The ALP activity of the cells cultured for 3d and 7 d on clodronate- HA bioceramics was slightly higher than that on HA bioceramics, but the difference was not significant. This result indicated that clodronate- HA bioceramics had favorable cytocompatibility to be used as bone scaffold with potential ability to improve osteogenesis.

  10. Aligned and random nanofibrous nanocomposite scaffolds for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Amir Doustgani

    2013-01-01

    Full Text Available Abstract  Aligned and random nanocomposite nanofibrous scaffolds were electrospun from polycaprolactone (PCL, poly (vinyl alcohol (PVA and hydroxyapatite nanoparticles (nHA. The morphology and mechanical characteristics of the nanofibers were evaluated using scanning electron microscopy and tensile testing, respectively. Scanning electron microscopy revealed fibers with an average diameter of 123 ± 32 nm and 339 ± 107 nm for aligned and random nanofibers, respectively. The mechanical data indicated the higher tensile strength and elastic modulus of aligned nanofibers. The in vitro biocompatibility of aligned and random nanofibrous scaffolds was also assessed by growing mesenchymal stem cells (MSCs, and investigating the proliferation and alkaline phosphatase activity (ALP on different nanofibrous scaffolds. Our  findings  showed  that  the  alignment  orientation  of  nanofibers  enhanced  the osteogenic differentiation of stem cells. The in vitro results showed that the aligned biocomposite nanofibrous scaffolds of PCL/nHA/PVA could be a potential substrate for tissue engineering applications, especially in the field of artificial bone implant.

  11. Biocompatible xanthan/polypyrrole scaffolds for tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Blasques Bueno, Vania; Harumi Takahashi, Suelen; Catalani, Luiz Henrique; Cordoba de Torresi, Susana Ines; Siqueira Petri, Denise Freitas, E-mail: dfsp@iq.usp.br

    2015-07-01

    Polypyrrole (PPy) was electropolymerized in xanthan hydrogels (XCA), resulting in electroactive XCAPPy scaffolds with (15 ± 3) wt.% PPy and (40 ± 10) μm thick. The physicochemical characterization of hybrid XCAPPy scaffolds was performed by means of cyclic voltammetry, swelling tests, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM) and tensile tests. XCAPPy swelled ~ 80% less than XCA. FTIR spectra and thermal analyses did not evidence strong interaction between PPy and XCA matrix. XCAPPy presented a porous stratified structure resulting from the arrangement of PPy chains parallel to XCA surface. Under stress XCAPPy presented larger strain than neat XCA probably due to the sliding of planar PPy chains. The adhesion and proliferation of fibroblasts onto XCA and XCAPPy were evaluated in the absence and in the presence of external magnetic field (EMF) of 0.4 T, after one day, 7 days, 14 days and 21 days. Fibroblast proliferation was more pronounced onto XCAPPy than onto XCA, due to its higher hydrophobicity and surface roughness. EMF stimulated cell proliferation onto both scaffolds. - Highlights: • Hybrid networks of xanthan and polypyrrole were used as scaffolds for fibroblasts. • Hybrid networks were more hydrophobic and more elastic than neat xanthan. • Cell proliferation onto hybrid networks and neat xanthan increased with the time. • Cell proliferation was more pronounced onto hybrid networks than on neat xanthan. • External magnetic field stimulated cell growth onto hybrid networks and neat xanthan.

  12. Computers, Nanotechnology and Mind

    Science.gov (United States)

    Ekdahl, Bertil

    2008-10-01

    In 1958, two years after the Dartmouth conference, where the term artificial intelligence was coined, Herbert Simon and Allen Newell asserted the existence of "machines that think, that learn and create." They were further prophesying that the machines' capacity would increase and be on par with the human mind. Now, 50 years later, computers perform many more tasks than one could imagine in the 1950s but, virtually, no computer can do more than could the first digital computer, developed by John von Neumann in the 1940s. Computers still follow algorithms, they do not create them. However, the development of nanotechnology seems to have given rise to new hopes. With nanotechnology two things are supposed to happen. Firstly, due to the small scale it will be possible to construct huge computer memories which are supposed to be the precondition for building an artificial brain, secondly, nanotechnology will make it possible to scan the brain which in turn will make reverse engineering possible; the mind will be decoded by studying the brain. The consequence of such a belief is that the brain is no more than a calculator, i.e., all that the mind can do is in principle the results of arithmetical operations. Computers are equivalent to formal systems which in turn was an answer to an idea by Hilbert that proofs should contain ideal statements for which operations cannot be applied in a contentual way. The advocates of artificial intelligence will place content in a machine that is developed not only to be free of content but also cannot contain content. In this paper I argue that the hope for artificial intelligence is in vain.

  13. Fabrication and Characterization of Collagen-Immobilized Porous PHBV/HA Nano composite Scaffolds for Bone Tissue Engineering

    International Nuclear Information System (INIS)

    Jin-Young, B.; Zhi-Cai, X.; Giseop, K.; Keun-Byoung, Y.; Soo-Young, P.; Lee, S.P.; Inn-Kyu, K.

    2012-01-01

    The porous composite scaffolds (PHBV/HA) consisting of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and hydroxyapatite (HA) were fabricated using a hot-press machine and salt-leaching. Collagen (type I) was then immobilized on the surface of the porous PHBV/HA composite scaffolds to improve tissue compatibility. The structure and morphology of the collagen-immobilized composite scaffolds (PHBV/HA/Col) were investigated using a scanning electron microscope (SEM), Fourier transform infrared (FTIR), and electron spectroscopy for chemical analysis (ESCA). The potential of the porous PHBV/HA/Col composite scaffolds for use as a bone scaffold was assessed by an experiment with osteoblast cells (MC3T3-E1) in terms of cell adhesion, proliferation, and differentiation. The results showed that the PHBV/HA/Col composite scaffolds possess better cell adhesion and significantly higher proliferation and differentiation than the PHBV/HA composite scaffolds and the PHBV scaffolds. These results suggest that the PHBV/HA/Col composite scaffolds have a high potential for use in the field of bone regeneration and tissue engineering.

  14. Factorial Study of Compressive Mechanical Properties and Primary In Vitro Osteoblast Response of PHBV/PLLA Scaffolds

    Directory of Open Access Journals (Sweden)

    Naznin Sultana

    2012-01-01

    Full Text Available For bone tissue regeneration, composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramics have been regarded as promising biomimetic systems. Polymer blends of poly(hydroxybutyrate-co-hydroxyvalerate (PHBV and poly(L-lactic acid (PLLA can be used as the polymer matrix to control the degradation rate. In order to render the scaffolds osteoconductive, nano-sized hydroxyapatite (nHA particles can be incorporated into the polymer matrix. In the first part of this study, a factorial design approach to investigate the influence of materials on the initial compressive mechanical properties of the scaffolds was studied. In the second part, the protein adsorption behavior and the attachment and morphology of osteoblast-like cells (Saos-2 of the scaffolds in vitro were also studied. It was observed that nHA incorporated PHBV/PLLA composite scaffolds adsorbed more bovine serum albumin (BSA protein than PHBV or PHBV/PLLA scaffolds. In vitro studies also revealed that the attachment of human osteoblastic cells (SaOS-2 was significantly higher in nHA incorporated PHBV/PLLA composite scaffolds. From the SEM micrographs of nHA incorporated PHBV/PLLA composite scaffolds seeded with SaOS-2 cells after a 7-day cell culture period, it was observed that the cells were well expanded and spread in all directions on the scaffolds.

  15. Animal Mind and Consciousness

    OpenAIRE

    Richterová, Klaudie

    2017-01-01

    Název diplomové práce: Mysl a vědomí u zvířat Vedoucí práce: prof. Karel Thein, Ph.D. Vypracovala: Bc. Klaudie Richterová Abstract This thesis examines the issue of cognition, mind and consciousness of living beings other than humans. It starts with the attitudes of two contemporary thinkers: Thomas Nagel and Daniel C. Dennett. In connection with their opinions, this thesis examines a certain number of questions: Might there be something like a subjective experience of life or being? How can ...

  16. Hyaluronic acid doped-poly(3,4-ethylenedioxythiophene)/chitosan/gelatin (PEDOT-HA/Cs/Gel) porous conductive scaffold for nerve regeneration

    International Nuclear Information System (INIS)

    Wang, Shuping; Guan, Shui; Zhu, Zhibo; Li, Wenfang; Liu, Tianqing; Ma, Xuehu

    2017-01-01

    Conducting polymer, as a “smart” biomaterial, has been increasingly used to construct tissue engineered scaffold for nerve tissue regeneration. In this study, a novel porous conductive scaffold was prepared by incorporating conductive hyaluronic acid (HA) doped-poly(3,4-ethylenedioxythiophene) (PEDOT-HA) nanoparticles into a chitosan/gelatin (Cs/Gel) matrix. The physicochemical characteristics of Cs/Gel scaffold with 0–10 wt% PEDOT-HA were analyzed and the results indicated that the incorporation of PEDOT-HA into scaffold increased the electrical and mechanical properties while decreasing the porosity and water absorption. Moreover, in vitro biodegradation of scaffold displayed a declining trend with the PEDOT-HA content increased. About the biocompatibility of conductive scaffold, neuron-like rat phaeochromocytoma (PC12) cells were cultured in scaffold to evaluate cell adhesion and growth. 8% PEDOT-HA/Cs/Gel scaffold had a higher cell adhesive efficiency and cell viability than the other conductive scaffolds. Furthermore, cells in the scaffold with 8 wt% PEDOT-HA expressed higher synapse growth gene of GAP43 and SYP compared with Cs/Gel control group. These results suggest that 8%PEDOT-HA/Cs/Gel scaffold is an attractive cell culture conductive substrate which could support cell adhesion, survival, proliferation, and synapse growth for the application in nerve tissue regeneration. - Highlights: • A porous conductive scaffold was prepared by freeze-drying method. • Conductive scaffold could support PC12 cells adhesion, survival, and proliferation. • Cells in conductive scaffold expressed high synapse growth gene of GAP43 and SYP.

  17. Hyaluronic acid doped-poly(3,4-ethylenedioxythiophene)/chitosan/gelatin (PEDOT-HA/Cs/Gel) porous conductive scaffold for nerve regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuping; Guan, Shui, E-mail: guanshui@dlut.edu.cn; Zhu, Zhibo; Li, Wenfang; Liu, Tianqing; Ma, Xuehu

    2017-02-01

    Conducting polymer, as a “smart” biomaterial, has been increasingly used to construct tissue engineered scaffold for nerve tissue regeneration. In this study, a novel porous conductive scaffold was prepared by incorporating conductive hyaluronic acid (HA) doped-poly(3,4-ethylenedioxythiophene) (PEDOT-HA) nanoparticles into a chitosan/gelatin (Cs/Gel) matrix. The physicochemical characteristics of Cs/Gel scaffold with 0–10 wt% PEDOT-HA were analyzed and the results indicated that the incorporation of PEDOT-HA into scaffold increased the electrical and mechanical properties while decreasing the porosity and water absorption. Moreover, in vitro biodegradation of scaffold displayed a declining trend with the PEDOT-HA content increased. About the biocompatibility of conductive scaffold, neuron-like rat phaeochromocytoma (PC12) cells were cultured in scaffold to evaluate cell adhesion and growth. 8% PEDOT-HA/Cs/Gel scaffold had a higher cell adhesive efficiency and cell viability than the other conductive scaffolds. Furthermore, cells in the scaffold with 8 wt% PEDOT-HA expressed higher synapse growth gene of GAP43 and SYP compared with Cs/Gel control group. These results suggest that 8%PEDOT-HA/Cs/Gel scaffold is an attractive cell culture conductive substrate which could support cell adhesion, survival, proliferation, and synapse growth for the application in nerve tissue regeneration. - Highlights: • A porous conductive scaffold was prepared by freeze-drying method. • Conductive scaffold could support PC12 cells adhesion, survival, and proliferation. • Cells in conductive scaffold expressed high synapse growth gene of GAP43 and SYP.

  18. The benefits of dispositional mindfulness in physical health: a longitudinal study of female college students.

    Science.gov (United States)

    Murphy, Megan J; Mermelstein, Liza C; Edwards, Katie M; Gidycz, Christine A

    2012-01-01

    This article examines the relationship between dispositional mindfulness, health behaviors (eg, sleep, eating, and exercise), and physical health. Participants included 441 college women. Women completed self-report surveys at the beginning and end of a 10-week academic quarter. The study was conducted over 5 academic quarters from fall 2008 to fall 2010. Findings indicated that higher levels of dispositional mindfulness were related to healthier eating practices, better quality of sleep, and better physical health. Dispositional mindfulness contributed to better physical health even after controlling for traditional health habits. Finally, bidirectional mediational relationships were found between healthy eating and dispositional mindfulness as well as between sleep quality and dispositional mindfulness when physical health was the outcome variable. Findings suggest that incorporating mindfulness training into programming on college campuses may be beneficial, as results indicate that dispositional mindfulness is related to positive physical health among college students.

  19. Mindfulness Interventions in Physical Rehabilitation: A Scoping Review.

    Science.gov (United States)

    Hardison, Mark E; Roll, Shawn C

    2016-01-01

    A scoping review was conducted to describe how mindfulness is used in physical rehabilitation, identify implications for occupational therapy practice, and guide future research on clinical mindfulness interventions. A systematic search of four literature databases produced 1,524 original abstracts, of which 16 articles were included. Although only 3 Level I or II studies were identified, the literature included suggests that mindfulness interventions are helpful for patients with musculoskeletal and chronic pain disorders and demonstrate trends toward outcome improvements for patients with neurocognitive and neuromotor disorders. Only 2 studies included an occupational therapist as the primary mindfulness provider, but all mindfulness interventions in the selected studies fit within the occupational therapy scope of practice according to the American Occupational Therapy Association's Occupational Therapy Practice Framework: Domain and Process. Higher-level research is needed to evaluate the effects of mindfulness interventions in physical rehabilitation and to determine best practices for the use of mindfulness by occupational therapy practitioners. Copyright © 2016 by the American Occupational Therapy Association, Inc.

  20. Unauthorized Minds: How "Theory of Mind" Theory Misrepresents Autism

    Science.gov (United States)

    Smukler, David

    2005-01-01

    Recent representations of autism frequently include an assumption that autism is the result of a "theory of mind" deficit (i.e., an inability to understand others' mental states). This notion is examined using a social constructionist perspective. The belief that autism is a sort of "mind-blindness" has much in common with earlier representations…

  1. Biodegradable poly (lactic acid-co-glycolic acid scaffolds as carriers for genetically-modified fibroblasts.

    Directory of Open Access Journals (Sweden)

    Tatjana Perisic

    Full Text Available Recent advances in gene delivery into cells allow improved therapeutic effects in gene therapy trials. To increase the bioavailability of applied cells, it is of great interest that transfected cells remain at the application site and systemic spread is minimized. In this study, we tested clinically used biodegradable poly(lactic acid-co-glycolic acid (PLGA scaffolds (Vicryl & Ethisorb as transient carriers for genetically modified cells. To this aim, we used human fibroblasts and examined attachment and proliferation of untransfected cells on the scaffolds in vitro, as well as the mechanical properties of the scaffolds at four time points (1, 3, 6 and 9 days of cultivation. Furthermore, the adherence of cells transfected with green fluorescent protein (GFP and vascular endothelial growth factor (VEGF165 and also VEGF165 protein secretion were investigated. Our results show that human fibroblasts adhere on both types of PLGA scaffolds. However, proliferation and transgene expression capacity were higher on Ethisorb scaffolds most probably due to a different architecture of the scaffold. Additionally, cultivation of the cells on the scaffolds did not alter their biomechanical properties. The results of this investigation could be potentially exploited in therapeutic regiments with areal delivery of transiently transfected cells and may open the way for a variety of applications of cell-based gene therapy, tissue engineering and regenerative medicine.

  2. Design of a Novel Two-Component Hybrid Dermal Scaffold for the Treatment of Pressure Sores.

    Science.gov (United States)

    Sharma, Vaibhav; Kohli, Nupur; Moulding, Dale; Afolabi, Halimat; Hook, Lilian; Mason, Chris; García-Gareta, Elena

    2017-11-01

    The aim of this study is to design a novel two-component hybrid scaffold using the fibrin/alginate porous hydrogel Smart Matrix combined to a backing layer of plasma polymerized polydimethylsiloxane (Sil) membrane to make the fibrin-based dermal scaffold more robust for the treatment of the clinically challenging pressure sores. A design criteria are established, according to which the Sil membranes are punched to avoid collection of fluid underneath. Manual peel test shows that native silicone does not attach to the fibrin/alginate component while the plasma polymerized silicone membranes are firmly bound to fibrin/alginate. Structural characterization shows that the fibrin/alginate matrix is intact after the addition of the Sil membrane. By adding a Sil membrane to the original fibrin/alginate scaffold, the resulting two-component scaffolds have a significantly higher shear or storage modulus G'. In vitro cell studies show that dermal fibroblasts remain viable, proliferate, and infiltrate the two-component hybrid scaffolds during the culture period. These results show that the design of a novel two-component hybrid dermal scaffold is successful according to the proposed design criteria. To the best of the authors' knowledge, this is the first study that reports the combination of a fibrin-based scaffold with a plasma-polymerized silicone membrane. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A collagen-based scaffold delivering exogenous microrna-29B to modulate extracellular matrix remodeling.

    Science.gov (United States)

    Monaghan, Michael; Browne, Shane; Schenke-Layland, Katja; Pandit, Abhay

    2014-04-01

    Directing appropriate extracellular matrix remodeling is a key aim of regenerative medicine strategies. Thus, antifibrotic interfering RNA (RNAi) therapy with exogenous microRNA (miR)-29B was proposed as a method to modulate extracellular matrix remodeling following cutaneous injury. It was hypothesized that delivery of miR-29B from a collagen scaffold will efficiently modulate the extracellular matrix remodeling response and reduce maladaptive remodeling such as aggressive deposition of collagen type I after injury. The release of RNA from the scaffold was assessed and its ability to silence collagen type I and collagen type III expression was evaluated in vitro. When primary fibroblasts were cultured with scaffolds doped with miR-29B, reduced levels of collagen type I and collagen type III mRNA expression were observed for up to 2 weeks of culture. When the scaffolds were applied to full thickness wounds in vivo, reduced wound contraction, improved collagen type III/I ratios and a significantly higher matrix metalloproteinase (MMP)-8: tissue inhibitor of metalloproteinase (TIMP)-1 ratio were detected when the scaffolds were functionalized with miR-29B. Furthermore, these effects were significantly influenced by the dose of miR-29B in the collagen scaffold (0.5 versus 5 μg). This study shows a potential of combining exogenous miRs with collagen scaffolds to improve extracellular matrix remodeling following injury.

  4. Electrospun Polyhydroxybutyrate and Poly(L-lactide-co-ε-caprolactone Composites as Nanofibrous Scaffolds

    Directory of Open Access Journals (Sweden)

    Donraporn Daranarong

    2014-01-01

    Full Text Available Electrospinning can produce nanofibrous scaffolds that mimic the architecture of the extracellular matrix and support cell attachment for tissue engineering applications. In this study, fibrous membranes of polyhydroxybutyrate (PHB with various loadings of poly(L-lactide-co-ε-caprolactone (PLCL were successfully prepared by electrospinning. In comparison to PLCL scaffolds, PLCL blends with PHB exhibited more irregular fibre diameter distributions and higher average fibre diameters but there were no significant differences in pore size. PLCL/PHB scaffolds were more hydrophilic (<120° with significantly reduced tensile strength (ca. 1 MPa compared to PLCL scaffolds (150.9±2.8∘ and 5.8±0.5 MPa. Increasing PLCL loading in PHB/PLCL scaffolds significantly increased the extension at break, (4–6-fold. PLCL/PHB scaffolds supported greater adhesion and proliferation of olfactory ensheathing cells (OECs than those exhibiting asynchronous growth on culture plates. Mitochondrial activity of cells cultivated on the electrospun blended membranes was enhanced compared to those grown on PLCL and PHB scaffolds (212, 179, and 153%, resp.. Analysis showed that PLCL/PHB nanofibrous membranes promoted cell cycle progression and reduced the onset of necrosis. Thus, electrospun PLCL/PHB composites promoted adhesion and proliferation of OECs when compared to their individual PLCL and PHB components suggesting potential in the repair and engineering of nerve tissue.

  5. Effect of Chemistry on Osteogenesis and Angiogenesis Towards Bone Tissue Engineering Using 3D Printed Scaffolds.

    Science.gov (United States)

    Bose, Susmita; Tarafder, Solaiman; Bandyopadhyay, Amit

    2017-01-01

    The functionality or survival of tissue engineering constructs depends on the adequate vascularization through oxygen transport and metabolic waste removal at the core. This study reports the presence of magnesium and silicon in direct three dimensional printed (3DP) tricalcium phosphate (TCP) scaffolds promotes in vivo osteogenesis and angiogenesis when tested in rat distal femoral defect model. Scaffolds with three different interconnected macro pore sizes were fabricated using direct three dimensional printing. In vitro ion release in phosphate buffer for 30 days showed sustained Mg 2+  and Si 4+  release from these scaffolds. Histolomorphology and histomorphometric analysis from the histology tissue sections revealed a significantly higher bone formation, between 14 and 20% for 4-16 weeks, and blood vessel formation, between 3 and 6% for 4-12 weeks, due to the presence of magnesium and silicon in TCP scaffolds compared to bare TCP scaffolds. The presence of magnesium in these 3DP TCP scaffolds also caused delayed TRAP activity. These results show that magnesium and silicon incorporated 3DP TCP scaffolds with multiscale porosity have huge potential for bone tissue repair and regeneration.

  6. 3D chitosan-gelatin-chondroitin porous scaffold improves osteogenic differentiation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Machado, C B [Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais (Brazil); Ventura, J M G [Department of Ceramics and Glass Engineering, University of Aveiro (Portugal); Lemos, A F [Department of Ceramics and Glass Engineering, University of Aveiro (Portugal); Ferreira, J M F [Department of Ceramics and Glass Engineering, University of Aveiro (Portugal); Leite, M F [Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais (Brazil); Goes, A M [Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais (Brazil)

    2007-06-01

    A porous 3D scaffold was developed to support and enhance the differentiation process of mesenchymal stem cells (MSC) into osteoblasts in vitro. The 3D scaffold was made with chitosan, gelatin and chondroitin and it was crosslinked by EDAC. The scaffold physicochemical properties were evaluated. SEM revealed the high porosity and interconnection of pores in the scaffold; rheological measurements show that the scaffold exhibits a characteristic behavior of strong gels. The elastic modulus found in compressive tests of the crosslinked scaffold was about 50 times higher than the non-crosslinked one. After 21 days, the 3D matrix submitted to hydrolytic degradation loses above 40% of its weight. MSC were collected from rat bone marrow and seeded in chitosan-gelatin-chondroitin 3D scaffolds and in 2D culture plates as well. MSC were differentiated into osteoblasts for 21 days. Cell proliferation and alkaline phosphatase activity were followed weekly during the osteogenic process. The osteogenic differentiation of MSC was improved in 3D culture as shown by MTT assay and alkaline phosphatase activity. On the 21st day, bone markers, osteopontin and osteocalcin, were detected by the PCR analysis. This study shows that the chitosan-gelatin-chondroitin 3D structure provides a good environment for the osteogenic process and enhances cellular proliferation.

  7. 3D chitosan-gelatin-chondroitin porous scaffold improves osteogenic differentiation of mesenchymal stem cells.

    Science.gov (United States)

    Machado, C B; Ventura, J M G; Lemos, A F; Ferreira, J M F; Leite, M F; Goes, A M

    2007-06-01

    A porous 3D scaffold was developed to support and enhance the differentiation process of mesenchymal stem cells (MSC) into osteoblasts in vitro. The 3D scaffold was made with chitosan, gelatin and chondroitin and it was crosslinked by EDAC. The scaffold physicochemical properties were evaluated. SEM revealed the high porosity and interconnection of pores in the scaffold; rheological measurements show that the scaffold exhibits a characteristic behavior of strong gels. The elastic modulus found in compressive tests of the crosslinked scaffold was about 50 times higher than the non-crosslinked one. After 21 days, the 3D matrix submitted to hydrolytic degradation loses above 40% of its weight. MSC were collected from rat bone marrow and seeded in chitosan-gelatin-chondroitin 3D scaffolds and in 2D culture plates as well. MSC were differentiated into osteoblasts for 21 days. Cell proliferation and alkaline phosphatase activity were followed weekly during the osteogenic process. The osteogenic differentiation of MSC was improved in 3D culture as shown by MTT assay and alkaline phosphatase activity. On the 21st day, bone markers, osteopontin and osteocalcin, were detected by the PCR analysis. This study shows that the chitosan-gelatin-chondroitin 3D structure provides a good environment for the osteogenic process and enhances cellular proliferation.

  8. 3D chitosan-gelatin-chondroitin porous scaffold improves osteogenic differentiation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Machado, C B; Ventura, J M G; Lemos, A F; Ferreira, J M F; Leite, M F; Goes, A M

    2007-01-01

    A porous 3D scaffold was developed to support and enhance the differentiation process of mesenchymal stem cells (MSC) into osteoblasts in vitro. The 3D scaffold was made with chitosan, gelatin and chondroitin and it was crosslinked by EDAC. The scaffold physicochemical properties were evaluated. SEM revealed the high porosity and interconnection of pores in the scaffold; rheological measurements show that the scaffold exhibits a characteristic behavior of strong gels. The elastic modulus found in compressive tests of the crosslinked scaffold was about 50 times higher than the non-crosslinked one. After 21 days, the 3D matrix submitted to hydrolytic degradation loses above 40% of its weight. MSC were collected from rat bone marrow and seeded in chitosan-gelatin-chondroitin 3D scaffolds and in 2D culture plates as well. MSC were differentiated into osteoblasts for 21 days. Cell proliferation and alkaline phosphatase activity were followed weekly during the osteogenic process. The osteogenic differentiation of MSC was improved in 3D culture as shown by MTT assay and alkaline phosphatase activity. On the 21st day, bone markers, osteopontin and osteocalcin, were detected by the PCR analysis. This study shows that the chitosan-gelatin-chondroitin 3D structure provides a good environment for the osteogenic process and enhances cellular proliferation

  9. Validation of scaffold design optimization in bone tissue engineering: finite element modeling versus designed experiments.

    Science.gov (United States)

    Uth, Nicholas; Mueller, Jens; Smucker, Byran; Yousefi, Azizeh-Mitra

    2017-02-21

    This study reports the development of biological/synthetic scaffolds for bone tissue engineering (TE) via 3D bioplotting. These scaffolds were composed of poly(L-lactic-co-glycolic acid) (PLGA), type I collagen, and nano-hydroxyapatite (nHA) in an attempt to mimic the extracellular matrix of bone. The solvent used for processing the scaffolds was 1,1,1,3,3,3-hexafluoro-2-propanol. The produced scaffolds were characterized by scanning electron microscopy, microcomputed tomography, thermogravimetric analysis, and unconfined compression test. This study also sought to validate the use of finite-element optimization in COMSOL Multiphysics for scaffold design. Scaffold topology was simplified to three factors: nHA content, strand diameter, and strand spacing. These factors affect the ability of the scaffold to bear mechanical loads and how porous the structure can be. Twenty four scaffolds were constructed according to an I-optimal, split-plot designed experiment (DE) in order to generate experimental models of the factor-response relationships. Within the design region, the DE and COMSOL models agreed in their recommended optimal nHA (30%) and strand diameter (460 μm). However, the two methods disagreed by more than 30% in strand spacing (908 μm for DE; 601 μm for COMSOL). Seven scaffolds were 3D-bioplotted to validate the predictions of DE and COMSOL models (4.5-9.9 MPa measured moduli). The predictions for these scaffolds showed relative agreement for scaffold porosity (mean absolute percentage error of 4% for DE and 13% for COMSOL), but were substantially poorer for scaffold modulus (51% for DE; 21% for COMSOL), partly due to some simplifying assumptions made by the models. Expanding the design region in future experiments (e.g., higher nHA content and strand diameter), developing an efficient solvent evaporation method, and exerting a greater control over layer overlap could allow developing PLGA-nHA-collagen scaffolds to meet the mechanical requirements for

  10. Mechanosensation across borders: fibroblasts inside a macroporous scaffold sense and respond to the mechanical environment beyond the scaffold walls.

    Science.gov (United States)

    Könnig, D; Herrera, A; Duda, G N; Petersen, A

    2018-01-01

    In tissue defects, cells face distinct mechanical boundary conditions, but how this influences early stages of tissue regeneration remains largely unknown. Biomaterials are used to fill defects but also to provide specific mechanical or geometrical signals. However, they might at the same time shield mechanical information from surrounding tissues that is relevant for tissue functionalisation. This study investigated how fibroblasts in a soft macroporous biomaterial scaffold respond to distinct mechanical environments while they form microtissues. Different boundary stiffnesses counteracting scaffold contraction were provided via a newly developed in vitro setup. Online monitoring over 14 days revealed 3.0 times lower microtissue contraction but 1.6 times higher contraction force for high vs. low stiffness. This difference was significant already after 48 h, a very early stage of microtissue growth. The microtissue's mechanical and geometrical adaptation indicated a collective cellular behaviour and mechanical communication across scaffold pore walls. Surprisingly, the stiffness of the environment influenced cell behaviour even inside macroporous scaffolds where direct cell-cell contacts are hindered. Mechanical communication between cells via traction forces is essential for tissue adaptation to the environment and should not be blocked by rigid biomaterials. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Predicting permeability of regular tissue engineering scaffolds: scaling analysis of pore architecture, scaffold length, and fluid flow rate effects.

    Science.gov (United States)

    Rahbari, A; Montazerian, H; Davoodi, E; Homayoonfar, S

    2017-02-01

    The main aim of this research is to numerically obtain the permeability coefficient in the cylindrical scaffolds. For this purpose, a mathematical analysis was performed to derive an equation for desired porosity in terms of morphological parameters. Then, the considered cylindrical geometries were modeled and the permeability coefficient was calculated according to the velocity and pressure drop values based on the Darcy's law. In order to validate the accuracy of the present numerical solution, the obtained permeability coefficient was compared with the published experimental data. It was observed that this model can predict permeability with the utmost accuracy. Then, the effect of geometrical parameters including porosity, scaffold pore structure, unit cell size, and length of the scaffolds as well as entrance mass flow rate on the permeability of porous structures was studied. Furthermore, a parametric study with scaling laws analysis of sample length and mass flow rate effects on the permeability showed good fit to the obtained data. It can be concluded that the sensitivity of permeability is more noticeable at higher porosities. The present approach can be used to characterize and optimize the scaffold microstructure due to the necessity of cell growth and transferring considerations.

  12. Nanosized Mesoporous Bioactive Glass/Poly(lactic-co-glycolic Acid Composite-Coated CaSiO3 Scaffolds with Multifunctional Properties for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Mengchao Shi

    2014-01-01

    Full Text Available It is of great importance to prepare multifunctional scaffolds combining good mechanical strength, bioactivity, and drug delivery ability for bone tissue engineering. In this study, nanosized mesoporous bioglass/poly(lactic-co-glycolic acid composite-coated calcium silicate scaffolds, named NMBG-PLGA/CS, were successfully prepared. The morphology and structure of the prepared scaffolds were characterized by scanning electron microscopy and X-ray diffraction. The effects of NMBG on the apatite mineralization activity and mechanical strength of the scaffolds and the attachment, proliferation, and alkaline phosphatase activity of MC3T3 cells as well as drug ibuprofen delivery properties were systematically studied. Compared to pure CS scaffolds and PLGA/CS scaffolds, the prepared NMBG-PLGA/CS scaffolds had greatly improved apatite mineralization activity in simulated body fluids, much higher mechanical property, and supported the attachment of MC3T3 cells and enhanced the cell proliferation and ALP activity. Furthermore, the prepared NMBG-PLGA/CS scaffolds could be used for delivering ibuprofen with a sustained release profile. Our study suggests that the prepared NMBG-PLGA/CS scaffolds have improved physicochemical, biological, and drug-delivery property as compared to conventional CS scaffolds, indicating that the multifunctional property of the prepared scaffolds for the potential application of bone tissue engineering.

  13. Antimicrobial Cu-bearing stainless steel scaffolds

    International Nuclear Information System (INIS)

    Wang, Qiang; Ren, Ling; Li, Xiaopeng; Zhang, Shuyuan; Sercombe, Timothy B.; Yang, Ke

    2016-01-01

    Copper-bearing stainless steel scaffolds with two different structures (Body Centered Cubic and Gyroid labyrinth) at two solid fractions (25% and 40%) were fabricated from both 316L powder and a mixture of 316L and elemental Cu powder using selective laser melting, and relative 316L scaffolds were served as control group. After processing, the antimicrobial testing demonstrated that the 316L-Cu scaffolds presented excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus, and the cell viability assay indicated that there was no cytotoxic effect of 316L-Cu scaffolds on rat marrow mesenchymal stem cells. As such, these have the potential to reduce implant-associated infections. The Cu was also found to homogeneously distribute within the microstructure by scanning electronic microcopy. The addition of Cu would not significantly affect its strength and stiffness compared to 316L scaffold, and the stiffness of all the scaffolds (3-20GPa) is similar to that of bone and much less than that of bulk stainless steel. Consequently, fabrication of such low stiffness porous structures, especially coupled with the addition of antimicrobial Cu, may provide a new direction for medical stainless steels. - Highlights: • 316L-Cu scaffolds were fabricated by using selective laser melting (SLM). • 316L-Cu scaffolds showed satisfied antimicrobial activities. • 316L-Cu scaffolds have no cytotoxic effect on normal cells. • Other properties of 316L-Cu scaffolds were similar to 316L scaffolds. • 316L-Cu scaffolds have the potential to be used in orthopedic applications.

  14. Antimicrobial Cu-bearing stainless steel scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiang, E-mail: mfqwang@163.com [School of Stomatology, China Medical University, Shenyang 110002 (China); Ren, Ling [Institute of Metal Research, Chinese Academy of Sciences (China); Li, Xiaopeng [School of Mechanical and Chemical Engineering, The University of Western Australia (Australia); Zhang, Shuyuan [Institute of Metal Research, Chinese Academy of Sciences (China); Sercombe, Timothy B., E-mail: tim.sercombe@uwa.edu.au [School of Mechanical and Chemical Engineering, The University of Western Australia (Australia); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences (China)

    2016-11-01

    Copper-bearing stainless steel scaffolds with two different structures (Body Centered Cubic and Gyroid labyrinth) at two solid fractions (25% and 40%) were fabricated from both 316L powder and a mixture of 316L and elemental Cu powder using selective laser melting, and relative 316L scaffolds were served as control group. After processing, the antimicrobial testing demonstrated that the 316L-Cu scaffolds presented excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus, and the cell viability assay indicated that there was no cytotoxic effect of 316L-Cu scaffolds on rat marrow mesenchymal stem cells. As such, these have the potential to reduce implant-associated infections. The Cu was also found to homogeneously distribute within the microstructure by scanning electronic microcopy. The addition of Cu would not significantly affect its strength and stiffness compared to 316L scaffold, and the stiffness of all the scaffolds (3-20GPa) is similar to that of bone and much less than that of bulk stainless steel. Consequently, fabrication of such low stiffness porous structures, especially coupled with the addition of antimicrobial Cu, may provide a new direction for medical stainless steels. - Highlights: • 316L-Cu scaffolds were fabricated by using selective laser melting (SLM). • 316L-Cu scaffolds showed satisfied antimicrobial activities. • 316L-Cu scaffolds have no cytotoxic effect on normal cells. • Other properties of 316L-Cu scaffolds were similar to 316L scaffolds. • 316L-Cu scaffolds have the potential to be used in orthopedic applications.

  15. The mediating role of emotional exhaustion in the relationship of mindfulness with turnover intentions and job performance

    OpenAIRE

    Reb, J; Narayanan, J; Chaturvedi, S; Ekkirala, S

    2016-01-01

    The role of mindfulness in the workplace has emerged as a legitimate and growing area of organizational scholarship. T he present research examined the role of employee emotional exhaustion in mediating the relationship of mindfulness with turnover intentions and task performance . Drawing on theory and empirical research on both organizational behavior and mindfulness, w e predicted that more mindful employees would show lower turnover intentions and higher task performance and that th e s e...

  16. Specific mindfulness skills differentially predict creative performance

    NARCIS (Netherlands)

    Baas, M.; Nevicka, B.; ten Velden, F.S.

    2014-01-01

    Past work has linked mindfulness to improved emotion regulation, interpersonal skills, and basic cognitive abilities, but is unclear about the relation between mindfulness and creativity. Studies examining effects of mindfulness on factors pertinent to creativity suggest a uniform and positive

  17. Anisotropic Shape-Memory Alginate Scaffolds Functionalized with Either Type I or Type II Collagen for Cartilage Tissue Engineering.

    Science.gov (United States)

    Almeida, Henrique V; Sathy, Binulal N; Dudurych, Ivan; Buckley, Conor T; O'Brien, Fergal J; Kelly, Daniel J

    2017-01-01

    Regenerating articular cartilage and fibrocartilaginous tissue such as the meniscus is still a challenge in orthopedic medicine. While a range of different scaffolds have been developed for joint repair, none have facilitated the development of a tissue that mimics the complexity of soft tissues such as articular cartilage. Furthermore, many of these scaffolds are not designed to function in mechanically challenging joint environments. The overall goal of this study was to develop a porous, biomimetic, shape-memory alginate scaffold for directing cartilage regeneration. To this end, a scaffold was designed with architectural cues to guide cellular and neo-tissue alignment, which was additionally functionalized with a range of extracellular matrix cues to direct stem cell differentiation toward the chondrogenic lineage. Shape-memory properties were introduced by covalent cross-linking alginate using carbodiimide chemistry, while the architecture of the scaffold was modified using a directional freezing technique. Introducing such an aligned pore structure was found to improve the mechanical properties of the scaffold, and promoted higher levels of sulfated glycosaminoglycans (sGAG) and collagen deposition compared to an isotropic (nonaligned) pore geometry when seeded with adult human stem cells. Functionalization with collagen improved stem cell recruitment into the scaffold and facilitated more homogenous cartilage tissue deposition throughout the construct. Incorporating type II collagen into the scaffolds led to greater cell proliferation, higher sGAG and collagen accumulation, and the development of a stiffer tissue compared to scaffolds functionalized with type I collagen. The results of this study demonstrate how both scaffold architecture and composition can be tailored in a shape-memory alginate scaffold to direct stem cell differentiation and support the development of complex cartilaginous tissues.

  18. Cell–scaffold interaction within engineered tissue

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Haiping; Liu, Yuanyuan, E-mail: Yuanyuan_liu@shu.edu.cn; Jiang, Zhenglong; Chen, Weihua; Yu, Yongzhe; Hu, Qingxi

    2014-05-01

    The structure of a tissue engineering scaffold plays an important role in modulating tissue growth. A novel gelatin–chitosan (Gel–Cs) scaffold with a unique structure produced by three-dimensional printing (3DP) technology combining with vacuum freeze-drying has been developed for tissue-engineering applications. The scaffold composed of overall construction, micro-pore, surface morphology, and effective mechanical property. Such a structure meets the essential design criteria of an ideal engineered scaffold. The favorable cell–matrix interaction supports the active biocompatibility of the structure. The structure is capable of supporting cell attachment and proliferation. Cells seeded into this structure tend to maintain phenotypic shape and secreted large amounts of extracellular matrix (ECM) and the cell growth decreased the mechanical properties of scaffold. This novel biodegradable scaffold has potential applications for tissue engineering based upon its unique structure, which acts to support cell growth. - Highlights: • The scaffold is not only for providing a surface for cell residence but also for determining cell phenotype and retaining structural integrity. • The mechanical property of scaffold can be affected by activities of cell. • The scaffold provides a microenvironment for cell attachment, growth, and migration.

  19. Platelet lysate embedded scaffolds for skin regeneration.

    Science.gov (United States)

    Sandri, Giuseppina; Bonferoni, Maria Cristina; Rossi, Silvia; Ferrari, Franca; Mori, Michela; Cervio, Marila; Riva, Federica; Liakos, Ioannis; Athanassiou, Athanassia; Saporito, Francesca; Marini, Lara; Caramella, Carla

    2015-04-01

    The work presents the development of acellular scaffolds extemporaneously embedded with platelet lysate (PL), as an innovative approach in the field of tissue regeneration/reparation. PL embedded scaffolds should have a tridimensional architecture to support cell migration and growth, in order to restore skin integrity. For this reason, chondroitin sulfate (CS) was associated with sodium alginate (SA) to prepare highly porous systems. The developed scaffolds were characterized for chemical stability to γ-radiation, morphology, hydration and mechanical properties. Moreover, the capability of fibroblasts and endothelial cells to populate the scaffold was evaluated by means of proliferation test 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and confocal laser scanning microscopy study. The scaffolds, not altered by sterilization, were characterized by limited swelling and high flexibility, by foam-like structure with bubbles that formed a high surface area and irregular texture suitable for cell adhesion. Cell growth and scaffold population were evident on the bubble surface, where the cells appeared anchored to the scaffold structure. Scaffold network based on CS and SA demonstrated to be an effective support to enhance and to allow fibroblasts and endothelial cells (human umbilical vein endothelial cells, HUVEC) adhesion and proliferation. In particular, it could be hypothesized that cell adhesion was facilitated by the synergic effect of PL and CS. Although further in vivo evaluation is needed, on the basis of in vitro results, PL embedded scaffolds seem promising systems for skin wound healing.

  20. Teaching Design in Middle-School: Instructors' Concerns and Scaffolding Strategies

    Science.gov (United States)

    Bamberger, Yael M.; Cahill, Clara S.

    2013-04-01

    This study deals with engineering education in the middle-school level. Its focus is instructors' concerns in teaching design, as well as scaffolding strategies that can help teachers deal with these concerns. Through participatory action research, nine instructors engaged in a process of development and instruction of a curriculum about energy along with engineering design. A 50-h curriculum was piloted during a summer camp for 38 middle-school students. Data was collected through instructors' materials: observation field notes, daily reflections and post-camp discussions. In addition, students' artifacts and planning graphical models were collected in order to explore how instructors' concerns were aligned with students' learning. Findings indicate three main tensions that reflect instructors' main concerns: how to provide sufficient scaffolding yet encourage creativity, how to scaffold hands-on experiences that promote mindful planning, and how to scaffold students' modeling practices. Pedagogical strategies for teaching design that developed through this work are described, as well as the ways they address the National Research Council (A framework for K-12 science education: practices, crosscutting concepts, and core ideas. National Academies Press, Washington, DC, 2011) core ideas of engineering education and the International Technological Literacy standards (ITEA in Standards for technological literacy, 3rd edn. International Technology education Association, Reston, VA, 2007).

  1. Mindfulness Practices and Learning Economics

    Science.gov (United States)

    Borker, David R.

    2013-01-01

    There is a growing interest among educators in teaching and learning practices based on mindfulness, a concept derived from eastern meditative traditions. This paper describes how mindfulness practices and concepts can be used to enhance the student's learning experience in beginning economics courses. Specific areas with a high potential for…

  2. Mindfulness and the Beginning Teacher

    Science.gov (United States)

    Bernay, Ross S.

    2014-01-01

    This article reviews a hermeneutic phenomenological study of five beginning teachers who were introduced to mindfulness during their initial teacher education programme. The participants kept fortnightly journals and engaged in three interviews with the researcher to assess the benefits of using mindfulness during the first year of teaching. The…

  3. Baby-MIND neutrino detector

    Science.gov (United States)

    Mefodiev, A. V.; Kudenko, Yu. G.; Mineev, O. V.; Khotjantsev, A. N.

    2017-11-01

    The main objective of the Baby-MIND detector (Magnetized Iron Neutrino Detector) is the study of muon charge identification efficiency for muon momenta from 0.3 to 5 GeV/ c. This paper presents the results of measurement of the Baby-MIND parameters.

  4. Mind Maps as Classroom Exercises

    Science.gov (United States)

    Budd, John W.

    2004-01-01

    A Mind Map is an outline in which the major categories radiate from a central image and lesser categories are portrayed as branches of larger branches. The author describes an in-class exercise in which small groups of students each create a Mind Map for a specific topic. This exercise is another example of an active and collaborative learning…

  5. Try This: Collaborative Mind Mapping

    Science.gov (United States)

    Mendelson, Melissa

    2016-01-01

    In this "Try This" article, students learn about collaborative mind mapping. A mind map is a type of graphic organizer that allows for short ideas to be written and linked to related ideas on a "map." A central idea is placed in the middle of the paper with related ideas connected to the central idea as well as to other ideas.…

  6. Functionally graded electrospun scaffolds with tunable mechanical properties for vascular tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Vinoy [Center for Nanoscale Materials and Biointegration (CNMB), Department of Physics, University of Alabama at Birmingham (UAB), AL 35294 (United States); Zhang Xing [Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham (UAB), AL 35294 (United States); Catledge, Shane A [Center for Nanoscale Materials and Biointegration (CNMB), Department of Physics, University of Alabama at Birmingham (UAB), AL 35294 (United States); Vohra, Yogesh K [Center for Nanoscale Materials and Biointegration (CNMB), Department of Physics, University of Alabama at Birmingham (UAB), AL 35294 (United States)

    2007-12-15

    Electrospun tubular scaffolds (4 mm inner diameter) based on bio-artificial blends of polyglyconate (Maxon (registered) ) and proteins such as gelatin and elastin having a spatially designed multilayer structure were prepared for use as vascular tissue scaffolds. Scanning electron microscopy analysis of scaffolds showed a random nanofibrous morphology with fiber diameter in the range of 200-400 nm for protein-blended Maxon, which mimics the nanoscale dimensions of collagen (50-500 nm). The scaffolds have a well interconnected pore structure and porosity up to 82%, with protein blending and multi-layering in contrast to electrospun Maxon (registered) scaffolds (67%). Fourier-transform infrared spectroscopy, x-ray diffraction and differential scanning calorimetry results confirmed the blended composition and crystallinity of fibers. Uniaxial tensile testing revealed a strength of 14.46 {+-} 0.42 MPa and a modulus of 15.44 {+-} 2.53 MPa with a failure strain of 322.5 {+-} 10% for a pure Maxon (registered) scaffold. The blending of polyglyconate with biopolymers decreased the tensile properties in general, with an exception of the tensile modulus (48.38 {+-} 2 MPa) of gelatin/Maxon mesh, which was higher than that of the pure Maxon (registered) scaffold. Trilayered tubular scaffolds of gelatin/elastin, gelatin/elastin/Maxon and gelatin/Maxon (GE-GEM-GM) that mimic the complex trilayer matrix structure of natural artery have been prepared by sequential electrospinning. Tensile testing under dry conditions revealed a tensile strength of 2.71 {+-} 0.2 MPa and a modulus of 20.4 {+-} 3 MPa with a failure strain of 140 {+-} 10%. However, GE-GEM-GM scaffolds tested under wet conditions after soaking in a phosphate buffered saline medium at 37 {sup 0}C for 24 h exhibited mechanical properties (2.5 MPa tensile strength and 9 MPa tensile modulus) comparable to those of native femoral artery.

  7. Functionally graded electrospun scaffolds with tunable mechanical properties for vascular tissue regeneration

    International Nuclear Information System (INIS)

    Thomas, Vinoy; Zhang Xing; Catledge, Shane A; Vohra, Yogesh K

    2007-01-01

    Electrospun tubular scaffolds (4 mm inner diameter) based on bio-artificial blends of polyglyconate (Maxon (registered) ) and proteins such as gelatin and elastin having a spatially designed multilayer structure were prepared for use as vascular tissue scaffolds. Scanning electron microscopy analysis of scaffolds showed a random nanofibrous morphology with fiber diameter in the range of 200-400 nm for protein-blended Maxon, which mimics the nanoscale dimensions of collagen (50-500 nm). The scaffolds have a well interconnected pore structure and porosity up to 82%, with protein blending and multi-layering in contrast to electrospun Maxon (registered) scaffolds (67%). Fourier-transform infrared spectroscopy, x-ray diffraction and differential scanning calorimetry results confirmed the blended composition and crystallinity of fibers. Uniaxial tensile testing revealed a strength of 14.46 ± 0.42 MPa and a modulus of 15.44 ± 2.53 MPa with a failure strain of 322.5 ± 10% for a pure Maxon (registered) scaffold. The blending of polyglyconate with biopolymers decreased the tensile properties in general, with an exception of the tensile modulus (48.38 ± 2 MPa) of gelatin/Maxon mesh, which was higher than that of the pure Maxon (registered) scaffold. Trilayered tubular scaffolds of gelatin/elastin, gelatin/elastin/Maxon and gelatin/Maxon (GE-GEM-GM) that mimic the complex trilayer matrix structure of natural artery have been prepared by sequential electrospinning. Tensile testing under dry conditions revealed a tensile strength of 2.71 ± 0.2 MPa and a modulus of 20.4 ± 3 MPa with a failure strain of 140 ± 10%. However, GE-GEM-GM scaffolds tested under wet conditions after soaking in a phosphate buffered saline medium at 37 0 C for 24 h exhibited mechanical properties (2.5 MPa tensile strength and 9 MPa tensile modulus) comparable to those of native femoral artery

  8. Post Processing and Biological Evaluation of the Titanium Scaffolds for Bone Tissue Engineering.

    Science.gov (United States)

    Wysocki, Bartłomiej; Idaszek, Joanna; Szlązak, Karol; Strzelczyk, Karolina; Brynk, Tomasz; Kurzydłowski, Krzysztof J; Święszkowski, Wojciech

    2016-03-15

    Nowadays, post-surgical or post-accidental bone loss can be substituted by custom-made scaffolds fabricated by additive manufacturing (AM) methods from metallic powders. However, the partially melted powder particles must be removed in a post-process chemical treatment. The aim of this study was to investigate the effect of the chemical polishing with various acid baths on novel scaffolds' morphology, porosity and mechanical properties. In the first stage, Magics software (Materialise NV, Leuven, Belgium) was used to design a porous scaffolds with pore size equal to (A) 200 µm, (B) 500 µm and (C) 200 + 500 µm, and diamond cell structure. The scaffolds were fabricated from commercially pure titanium powder (CP Ti) using a SLM50 3D printing machine (Realizer GmbH, Borchen, Germany). The selective laser melting (SLM) process was optimized and the laser beam energy density in range of 91-151 J/mm³ was applied to receive 3D structures with fully dense struts. To remove not fully melted titanium particles the scaffolds were chemically polished using various HF and HF-HNO₃ acid solutions. Based on scaffolds mass loss and scanning electron (SEM) observations, baths which provided most uniform surface cleaning were proposed for each porosity. The pore and strut size after chemical treatments was calculated based on the micro-computed tomography (µ-CT) and SEM images. The mechanical tests showed that the treated scaffolds had Young's modulus close to that of compact bone. Additionally, the effect of pore size of chemically polished scaffolds on cell retention, proliferation and differentiation was studied using human mesenchymal stem cells. Small pores yielded higher cell retention within the scaffolds, which then affected their growth. This shows that in vitro cell performance can be controlled to certain extent by varying pore sizes.

  9. Geometrical versus Random β-TCP Scaffolds: Exploring the Effects on Schwann Cell Growth and Behavior.

    Directory of Open Access Journals (Sweden)

    Lauren Sweet

    Full Text Available Numerous studies have demonstrated that Schwann cells (SCs play a role in nerve regeneration; however, their role in innervating a bioceramic scaffold for potential application in bone regeneration is still unknown. Here we report the cell growth and functional behavior of SCs on β-tricalcium phosphate (β-TCP scaffolds arranged in 3D printed-lattice (P-β-TCP and randomly-porous, template-casted (N-β-TCP structures. Our results indicate that SCs proliferated well and expressed the phenotypic markers p75LNGFR and the S100-β subunit of SCs as well as displayed growth morphology on both scaffolds, but SCs showed spindle-shaped morphology with a significant degree of SCs alignment on the P-β-TCP scaffolds, seen to a lesser degree in the N-β-TCP scaffold. The gene expressions of nerve growth factor (β-ngf, neutrophin-3 (nt-3, platelet-derived growth factor (pdgf-bb, and vascular endothelial growth factor (vegf-a were higher at day 7 than at day 14. While no significant differences in protein secretion were measured between these last two time points, the scaffolds promoted the protein secretion at day 3 compared to that on the cell culture plates. These results together imply that the β-TCP scaffolds can support SC cell growth and that the 3D-printed scaffold appeared to significantly promote the alignment of SCs along the struts. Further studies are needed to investigate the early and late stage relationship between gene expression and protein secretion of SCs on the scaffolds with refined characteristics, thus better exploring the potential of SCs to support vascularization and innervation in synthetic bone grafts.

  10. Development of an electrospun biomimetic polyurea scaffold suitable for vascular grafting.

    Science.gov (United States)

    Madhavan, Krishna; Frid, Maria G; Hunter, Kendall; Shandas, Robin; Stenmark, Kurt R; Park, Daewon

    2018-01-01

    The optimization of biomechanical and biochemical properties of a vascular graft to render properties relevant to physiological environments is a major challenge today. These critical properties of a vascular graft not only regulate its stability and integrity, but also control invasion of cells for scaffold remodeling permitting its integration with native tissue. In this work, we have synthesized a biomimetic scaffold by electrospinning a blend of a polyurea, poly(serinol hexamethylene urea) (PSHU), and, a polyester, poly-ε-caprolactone (PCL). Mechanical properties of the scaffold were varied by varying polymer blending ratio and electrospinning flow rate. Mechanical characterization revealed that scaffolds with lower PSHU content relative to PCL content resulted in elasticity close to native mammalian arteries. We also found that increasing electrospinning flow rates also increased the elasticity of the matrix. Optimization of elasticity generated scaffolds that enabled vascular smooth muscle cells (SMCs) to adhere, grow and maintain a SMC phenotype. The 30/70 scaffold also underwent slower degradation than scaffolds with higher PSHU content, thereby, providing the best option for in vivo remodeling. Further, Gly-Arg-Gly-Asp-Ser (RGD) covalently conjugated to the polyurea backbone in 30/70 scaffold resulted in significantly increased clotting times. Reducing surface thrombogenicity by the conjugation of RGD is critical to avoiding intimal hyperplasia. Hence, biomechanical and biochemical properties of a vascular graft can be balanced by optimizing synthesis parameters and constituent components. For these reasons, the optimized RGD-conjugated 30/70 scaffold electrospun at 2.5 or 5 mL/h has great potential as a suitable material for vascular grafting applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 278-290, 2018. © 2017 Wiley Periodicals, Inc.

  11. Biofunctional Ionic-Doped Calcium Phosphates: Silk Fibroin Composites for Bone Tissue Engineering Scaffolding.

    Science.gov (United States)

    Pina, S; Canadas, R F; Jiménez, G; Perán, M; Marchal, J A; Reis, R L; Oliveira, J M

    2017-01-01

    The treatment and regeneration of bone defects caused by traumatism or diseases have not been completely addressed by current therapies. Lately, advanced tools and technologies have been successfully developed for bone tissue regeneration. Functional scaffolding materials such as biopolymers and bioresorbable fillers have gained particular attention, owing to their ability to promote cell adhesion, proliferation, and extracellular matrix production, which promote new bone growth. Here, we present novel biofunctional scaffolds for bone regeneration composed of silk fibroin (SF) and β-tricalcium phosphate (β-TCP) and incorporating Sr, Zn, and Mn, which were successfully developed using salt-leaching followed by a freeze-drying technique. The scaffolds presented a suitable pore size, porosity, and high interconnectivity, adequate for promoting cell attachment and proliferation. The degradation behavior and compressive mechanical strengths showed that SF/ionic-doped TCP scaffolds exhibit improved characteristics for bone tissue engineering when compared with SF scaffolds alone. The in vitro bioactivity assays using a simulated body fluid showed the growth of an apatite layer. Furthermore, in vitro assays using human adipose-derived stem cells presented different effects on cell proliferation/differentiation when varying the doping agents in the biofunctional scaffolds. The incorporation of Zn into the scaffolds led to improved proliferation, while the Sr- and Mn-doped scaffolds presented higher osteogenic potential as demonstrated by DNA quantification and alkaline phosphatase activity. The combination of Sr with Zn led to an influence on cell proliferation and osteogenesis when compared with single ions. Our results indicate that biofunctional ionic-doped composite scaffolds are good candidates for further in vivo studies on bone tissue regeneration. © 2017 S. Karger AG, Basel.

  12. Porous poly(vinyl alcohol)/sepiolite bone scaffolds: Preparation, structure and mechanical properties

    International Nuclear Information System (INIS)

    Killeen, Derek; Frydrych, Martin; Chen Biqiong

    2012-01-01

    Porous poly(vinyl alcohol) (PVA)/sepiolite nanocomposite scaffolds containing 0–10 wt.% sepiolite were prepared by freeze-drying and thermally crosslinked with poly(arylic acid). The microstructure of the obtained scaffolds was characterised by scanning electron microscopy and micro-computed tomography, which showed a ribbon and ladder like interconnected structure. The incorporation of sepiolite increased the mean pore size and porosity of the PVA scaffold as well as the degree of anisotropy due to its fibrous structure. The tensile strength, modulus and energy at break of the PVA solid material that constructed the scaffold were found to improve with additions of sepiolite by up to 104%, 331% and 22% for 6 wt.% clay. Such enhancements were attributed to the strong interactions between the PVA and sepiolite, the good dispersion of sepiolite nanofibres in the matrix and the intrinsic properties of the nanofibres. However, the tensile properties of the PVA scaffold deteriorated in the presence of sepiolite because of the higher porosity, pore size and degree of anisotropy. The PVA/sepiolite nanocomposite scaffold containing 6 wt.% sepiolite was characterised by an interconnected structure, a porosity of 89.5% and a mean pore size of 79 μm and exhibited a tensile strength of 0.44 MPa and modulus of 14.9 MPa, which demonstrates potential for this type of materials to be further developed as bone scaffolds. - Highlights: ► Novel PAA-crosslinked PVA/sepiolite nanocomposite scaffolds were prepared. ► They were highly porous with interconnected structures and exhibited good mechanical properties. ► The effects of sepiolite nanofibres on structure and properties of the scaffolds were investigated. ► Sepiolite nanofibres improved the mechanical properties of the solid material significantly.

  13. Bone Morphogenic Protein-2 (rhBMP2)-Loaded Silk Fibroin Scaffolds to Enhance the Osteoinductivity in Bone Tissue Engineering

    Science.gov (United States)

    Du, Guang-Yu; He, Sheng-Wei; Sun, Chuan-Xiu; Mi, Li-Dong

    2017-10-01

    There is an increasing demand for formulations of silk fibroin (SF) scaffolds in biomedical applications. SF was crosslinked via glutaraldehyde with osteoinductive recombinant human bone morphogenic protein-2 (rhBMP2) of different ratios viz. (i) 3% SF with no rhBMP2 (SF), (ii) 3% SF with equal amount of rhBMP2 (SF+BMP2), and (iii) 12% SF with 3% of rhBMP2 (4SF+BMP2), and these solutions were used in electrospinning-based fabrication of nanoscaffolds for evaluating increased osteoinductive potential of SF scaffolds with rhBMP2. Stress-strain relationship suggested there is no loss in mechanical strength of fibers with addition of rhBMP2, and mechanical strength of scaffold was improved with increase in concentration of SF. rhBMP2 association increased the water retention capacity of scaffold as evident from swelling studies. Viability of hMSCs was found to be higher in conjugated scaffolds, and scaffolds do not exhibit any cytotoxicity towards guest cells. Cells were found to have higher alkaline phosphatase activity in conjugated scaffolds under in vitro and in vivo conditions which establishes the increased osteoinductivity of the novel construct. The scaffolds were found to be effective for in vivo bone formation as well.

  14. WiseScaffolder: an algorithm for the semi-automatic scaffolding of Next Generation Sequencing data.

    Science.gov (United States)

    Farrant, Gregory K; Hoebeke, Mark; Partensky, Frédéric; Andres, Gwendoline; Corre, Erwan; Garczarek, Laurence

    2015-09-03

    The sequencing depth provided by high-throughput sequencing technologies has allowed a rise in the number of de novo sequenced genomes that could potentially be closed without further sequencing. However, genome scaffolding and closure require costly human supervision that often results in genomes being published as drafts. A number of automatic scaffolders were recently released, which improved the global quality of genomes published in the last few years. Yet, none of them reach the efficiency of manual scaffolding. Here, we present an innovative semi-automatic scaffolder that additionally helps with chimerae resolution and generates valuable contig maps and outputs for manual improvement of the automatic scaffolding. This software was tested on the newly sequenced marine cyanobacterium Synechococcus sp. WH8103 as well as two reference datasets used in previous studies, Rhodobacter sphaeroides and Homo sapiens chromosome 14 (http://gage.cbcb.umd.edu/). The quality of resulting scaffolds was compared to that of three other stand-alone scaffolders: SSPACE, SOPRA and SCARPA. For all three model organisms, WiseScaffolder produced better results than other scaffolders in terms of contiguity statistics (number of genome fragments, N50, LG50, etc.) and, in the case of WH8103, the reliability of the scaffolds was confirmed by whole genome alignment against a closely related reference genome. We also propose an efficient computer-assisted strategy for manual improvement of the scaffolding, using outputs generated by WiseScaffolder, as well as for genome finishing that in our hands led to the circularization of the WH8103 genome. Altogether, WiseScaffolder proved more efficient than three other scaffolders for both prokaryotic and eukaryotic genomes and is thus likely applicable to most genome projects. The scaffolding pipeline described here should be of particular interest to biologists wishing to take advantage of the high added value of complete genomes.

  15. Mindful Learning: A Case Study of Langerian Mindfulness in Schools.

    Science.gov (United States)

    Davenport, Chase; Pagnini, Francesco

    2016-01-01

    The K-12 classroom applications of mindfulness as developed by Ellen Langer are discussed in a case study of a first-year charter school. Langerian Mindfulness, which is the act of drawing distinctions and noticing novelty, is deeply related to well-being and creativity, yet its impact has yet to be tested at the primary or secondary school level. The objective of the article is to display how Langerian Mindfulness strategies could increase 21st century skills and Social-Emotional Learning in primary classrooms. The New School San Francisco, an inquiry-based, socioeconomically and racially integrated charter school, serves as a model for mindful teaching and learning strategies. It is concluded that when mindful strategies are implemented, students have significant opportunities to exercise the 21st century skills of creativity, collaboration, communication and critical thinking. Langerian Mindfulness is also considered as a tool for increasing Social-Emotional Learning in integrated classrooms. It is recommended that mindful interventions be further investigated in the primary and secondary school context.

  16. Mindful Learning: A Case Study of Langerian Mindfulness in Schools

    Directory of Open Access Journals (Sweden)

    Chase Davenport

    2016-09-01

    Full Text Available The K-12 classroom applications of mindfulness as developed by Ellen Langer are discussed in a case study of a first-year charter school. Langerian Mindfulness, which is the act of drawing distinctions and noticing novelty, is deeply related to well-being and creativity, yet its impact has yet to be tested at the primary or secondary school level. The objective of the article is to display how Langerian Mindfulness strategies could increase 21st century skills and Social-Emotional Learning in primary classrooms. The New School San Francisco, an inquiry-based, socioeconomically and racially integrated charter school, serves as a model for mindful teaching and learning strategies. It is concluded that when mindful strategies are implemented, students have significant opportunities to exercise the 21st century skills of creativity, collaboration, communication and critical thinking. Langerian Mindfulness is also considered as a tool for increasing Social-Emotional Learning in integrated classrooms. It is recommended that mindful interventions be further investigated in the primary and secondary school context.

  17. Trait mindfulness and protective strategies for alcohol use: Implications for college student drinking.

    Science.gov (United States)

    Brett, Emma I; Leffingwell, Thad R; Leavens, Eleanor L

    2017-10-01

    The use of Protective Behavioral Strategies (PBS) has been strongly linked with decreased experience of alcohol-related consequences, making them a potential target for intervention. Additionally, mindfulness is associated with decreased experience of alcohol-related consequences. The purpose of the current study was to evaluate a model of PBS as a mediator of the effect of mindfulness on alcohol-related consequences. Additionally, mindfulness as a moderator of the relationship between PBS and alcohol use and consequences was examined. College students (N=239) at a large South Central university completed self-report measures of demographics, alcohol use and consequences, use of PBS, and trait mindfulness. Results indicated that both higher levels of mindfulness and using more PBS predicted decreased alcohol-related consequences and consumption, with PBS mediating both relationships (pmindfulness were more likely to use PBS, with individuals using more PBS experiencing fewer alcohol-related consequences and consuming fewer drinks per week. Mindfulness moderated the relationship between PBS and consequences, with a significantly stronger negative relationship for those with lower levels of mindfulness. Individuals who are higher in trait mindfulness are more likely to use PBS, which leads to a decrease in the experience of alcohol-related consequences. Furthermore, for individuals lower in mindfulness, low PBS use may lead to increased experience of alcohol consequences. Interventions that incorporate PBS may be most beneficial for students who are low in mindfulness and unlikely to engage in drinking control strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Drug-likeness analysis of traditional Chinese medicines: 2. Characterization of scaffold architectures for drug-like compounds, non-drug-like compounds, and natural compounds from traditional Chinese medicines.

    Science.gov (United States)

    Tian, Sheng; Li, Youyong; Wang, Junmei; Xu, Xiaojie; Xu, Lei; Wang, Xiaohong; Chen, Lei; Hou, Tingjun

    2013-01-21

    In order to better understand the structural features of natural compounds from traditional Chinese medicines, the scaffold architectures of drug-like compounds in MACCS-II Drug Data Report (MDDR), non-drug-like compounds in Available Chemical Directory (ACD), and natural compounds in Traditional Chinese Medicine Compound Database (TCMCD) were explored and compared. First, the different scaffolds were extracted from ACD, MDDR and TCMCD by using three scaffold representations, including Murcko frameworks, Scaffold Tree, and ring systems with different complexity and side chains. Then, by examining the accumulative frequency of the scaffolds in each dataset, we observed that the Level 1 scaffolds of the Scaffold Tree offer advantages over the other scaffold architectures to represent the scaffold diversity of the compound libraries. By comparing the similarity of the scaffold architectures presented in MDDR, ACD and TCMCD, structural overlaps were observed not only between MDDR and TCMCD but also between MDDR and ACD. Finally, Tree Maps were used to cluster the Level 1 scaffolds of the Scaffold Tree and visualize the scaffold space of the three datasets. The analysis of the scaffold architectures of MDDR, ACD and TCMCD shows that, on average, drug-like molecules in MDDR have the highest diversity while natural compounds in TCMCD have the highest complexity. According to the Tree Maps, it can be observed that the Level 1 scaffolds present in MDDR have higher diversity than those presented in TCMCD and ACD. However, some representative scaffolds in MDDR with high frequency show structural similarities to those in TCMCD and ACD, suggesting that some scaffolds in TCMCD and ACD may be potentially drug-like fragments for fragment-based and de novo drug design.

  19. SHOP: scaffold hopping by GRID-based similarity searches

    DEFF Research Database (Denmark)

    Bergmann, Rikke; Linusson, Anna; Zamora, Ismael

    2007-01-01

    A new GRID-based method for scaffold hopping (SHOP) is presented. In a fully automatic manner, scaffolds were identified in a database based on three types of 3D-descriptors. SHOP's ability to recover scaffolds was assessed and validated by searching a database spiked with fragments of known...... scaffolds were in the 31 top-ranked scaffolds. SHOP also identified new scaffolds with substantially different chemotypes from the queries. Docking analysis indicated that the new scaffolds would have similar binding modes to those of the respective query scaffolds observed in X-ray structures...

  20. Winning hearts and minds

    International Nuclear Information System (INIS)

    Drulia, M.R.

    1999-01-01

    'The greatest problem in communication is the illusion that it has been accomplished' (George Bernard Shaw). Over the past few decades we have seen major shifts in opinion as to what makes a business successful. The 1950's and 1960's saw a production focus whilst the 1970's and 1980's saw progressive change towards quality and 'customer is king' as key business drivers. A popular view now suggests that the next step change will be towards internal marketing, based on the concept that, in the future, winning employee support will be seen as the single biggest contributor to driving business performances. In summary, to win hearts and minds you must understand the needs of your audience, the intent of your communication activity, adopt a suitable style and match your deeds to your words

  1. Mindfulness i undervisningen

    DEFF Research Database (Denmark)

    Lau, Dorthe

    2012-01-01

    Hverdagen i skole og institutioner er fyldt med udfordringer og krav om læring og udvikling i fællesskabet. Dette stiller store krav til den enkelte, og de mange relationer i løbet af en dag. Dette kan i nogle tilfælde fjerne fokus fra den enkeltes evne til nærvær både i forhold til sig selv og i...... forhold til andre. Mindfulness i undervisningen er et redskab til at skabe et lærings- og udviklingsmiljø, hvor børn får erfaringer med at være til stede i sig selv, og hvor de oplever ro til at lære og være....

  2. Movies and the Mind

    DEFF Research Database (Denmark)

    Fingerhut, Joerg; Heimann, Katrin

    2017-01-01

    Over the last decade, the role of the spectators’ body has become considerably more important in theoretical as well as experimental approaches to film perception. However, most positions focus on how cinema has adapted to the spectator’s body over time, that is, to the basic principles of human...... perception and cognition, in developing its immersive power. This article presents the latest contributions to this topic, while also providing a new stance regarding the relationship between the mind and movies. Based on selected research from embodied approaches to cognition and picture perception, we...... suggest that humans learn to see film by integrating filmic means into their body schemas, and through this process develop a “filmic body”, available to them during film watching and, possibly, also off screen. Film language and film cognition are plastic products of mutual influence between films...

  3. Staying mindful in action

    DEFF Research Database (Denmark)

    Svalgaard, Lotte

    2016-01-01

    Action Learning is a well-proven method to integrate ‘task’ and ‘process’, as learning about team and self (process) takes place while delivering on a task or business challenge of real importance (task). An Action Lab® is an intensive Action Learning programme lasting for 5 days, which aims...... at balancing and integrating individual challenges and business challenges, as well as the ‘Action’ and the ‘Learning’ of Action Learning. However, in spite of the aspiration to balance and integrate ‘task’ and ‘process’, a tendency and a challenge is experienced: When deeply involved in delivering...... this tendency by sharing a study looking into what hinders and promotes mindful awareness on the process, while dealing with a business challenge in an Action Lab®. Drawing on the findings, the account of practice will share some recommendations for the Action Learning facilitator to take up the challenge...

  4. Changing your mind.

    Science.gov (United States)

    Walsh, Clare R; Johnson-Laird, P N

    2009-07-01

    When individuals detect an inconsistency in a set of propositions, they tend to change their minds about at least one proposition to resolve the inconsistency. The orthodox view from William James (1907) onward has been that a rational change should be minimal. We propose an alternative hypothesis according to which individuals seek to resolve inconsistencies by explaining their origins. We report four experiments corroborating the explanatory hypothesis. Experiment 1 showed that participants' explanations revised general conditional claims rather than specific categorical propositions. Experiment 2 showed that, when explanations did revise the categorical proposition, participants also tended to deny the consequences of a second generalization. Experiment 3 showed that this tendency persists when participants previously affirmed these consequences explicitly. Experiment 4 showed that, when participants could easily explain an inconsistency by revising a generalization, they were more likely to accept the consequences of a second generalization. All four results contravene minimalism but support the explanatory hypothesis.

  5. Memory, Mind and Language

    DEFF Research Database (Denmark)

    up a number of topics in the field, among them the question of synchrony vs. diachrony in the language sciences, and issues of how to investigate the relationship between language, brain and mind. The book proposes some preliminary solutions to that problem, and, most significantly, it touches...... on both general and specific issues in theory and analysis, e.g. ‘adverbs in English and Norwegian,’ ‘verb semantics,’ ‘pronouns in Estonian,’ ‘morphology and neurolinguistics,’ ‘word order and morphology,’ ‘the nature and use of prepotions’ and ‘speech acts.’ The contributing scholars come from a variety...

  6. In vitro biocompatibility of 45S5 Bioglass-derived glass-ceramic scaffolds coated with poly(3-hydroxybutyrate).

    Science.gov (United States)

    Bretcanu, Oana; Misra, Superb; Roy, Ipsita; Renghini, Chiara; Fiori, Fabrizio; Boccaccini, Aldo R; Salih, Vehid

    2009-02-01

    The aim of this work was to study the in vitro biocompatibility of glass-ceramic scaffolds based on 45S5 Bioglass, using a human osteosarcoma cell line (HOS-TE85). The highly porous scaffolds were produced by the foam replication technique. Two different types of scaffolds with different porosities were analysed. They were coated with a biodegradable polymer, poly(3-hydroxybutyrate) (P(3HB)). The scaffold bioactivity was evaluated by soaking in a simulated body fluid (SBF) for different durations. Compression strength tests were performed before and after immersion in SBF. These experiments showed that the scaffolds are highly bioactive, as after a few days of immersion in SBF a hydroxyapatite-like layer was formed on the scaffold's surface. It was also observed that P(3HB)-coated samples exhibited higher values of compression strength than uncoated samples. Biocompatibility assessment was carried out by qualitative evaluation of cell morphology after different culture periods, using scanning electron microscopy, while cell proliferation was determined by using the AlamarBlue assay. Alkaline phosphatase (ALP) and osteocalcin (OC) assays were used as quantitative in vitro indicators of osteoblast function. Two different types of medium were used for ALP and OC tests: normal supplemented medium and osteogenic medium. HOS cells were seeded and cultured onto the scaffolds for up to 2 weeks. The AlamarBlue assay showed that cells were able to proliferate and grow on the scaffold surface. After 7 days in culture, the P(3HB)-coated samples had a higher number of cells on their surfaces than the uncoated samples. Regarding ALP- and OC-specific activity, no significant differences were found between samples with different pore sizes. All scaffolds containing osteogenic medium seemed to have a slightly higher level of ALP and OC concentration. These experiments confirmed that Bioglass/P(3HB) scaffolds have potential as osteoconductive tissue engineering substrates for

  7. Dextran hydrogels incorporated with bioactive glass-ceramic: Nanocomposite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Nikpour, Parisa; Salimi-Kenari, Hamed; Fahimipour, Farahnaz; Rabiee, Sayed Mahmood; Imani, Mohammad; Dashtimoghadam, Erfan; Tayebi, Lobat

    2018-06-15

    A series of nanocomposite scaffolds comprised of dextran (Dex) and sol-gel derived bioactive glass ceramic nanoparticles (nBGC: 0-16 (wt%)) were fabricated as bioactive scaffolds for bone tissue engineering. Scanning electron microscopy showed Dex/nBGC scaffolds were consisting of a porous 3D microstructure with an average pore size of 240 μm. Energy-dispersive x-ray spectroscopy illustrated nBGC nanoparticles were homogenously distributed within the Dex matrix at low nBGC content (2 wt%), while agglomeration was observed at higher nBGC contents. It was found that the osmotic pressure and nBGC agglomeration at higher nBGC contents leads to increased water uptake, then reduction of the compressive modulus. Bioactivity of Dex/nBGC scaffolds was validated through apatite formation after submersion in the simulated body fluid. Dex/nBGC composite scaffolds were found to show improved human osteoblasts (HOBs) proliferation and alkaline phosphatase (ALP) activity with increasing nBGC content up to 16 (wt%) over two weeks. Owing to favorable physicochemical and bioactivity properties, the Dex/nBGC composite hydrogels can be offered as promising bioactive scaffolds for bone tissue engineering applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Trait Mindfulness and Cognitive Task Performance

    Directory of Open Access Journals (Sweden)

    Emalee J. W. Quickel

    2014-11-01

    Full Text Available Mindfulness meditation (MM training has been shown to have positive effects on working memory and focused attention tasks. Clarifying the construct of mindfulness is important so that mindfulness can be studied effectively in individual differences and cognition research. The current study tested whether trait mindfulness alone explains any of the variability on task performance. Five commonly used mindfulness scales, as well as six standardized and experimental attention and working memory tasks were administered to 164 participants with no meditation experience. Confirmatory factor analysis found that the common variance denoted by measures of trait mindfulness is unrelated to the common variance among tasks requiring focused attention. These results indicate that mindfulness scales may not be capturing the attentional aspects of mindfulness. Individuals who score high on mindfulness scales do not perform better on focused attention tasks than those who score lower on mindfulness scales. These results have implications for defining and operationalizing mindfulness.

  9. Quantum entanglement, indistinguishability, and the absent-minded driver's problem

    International Nuclear Information System (INIS)

    Cabello, Adan; Calsamiglia, John

    2005-01-01

    The absent-minded driver's problem illustrates that probabilistic strategies can give higher pay-offs than deterministic ones. We show that there are strategies using quantum entangled states that give even higher pay-offs, both for the original problem and for the generalized version with an arbitrary number of intersections and any possible set of pay-offs

  10. Crosslinked pullulan/cellulose acetate fibrous scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Atila, Deniz [Department of Engineering Sciences, Middle East Technical University (Turkey); Keskin, Dilek [Department of Engineering Sciences, Middle East Technical University (Turkey); Biomaterials and Tissue Engineering Center of Excellence, Middle East Technical University (Turkey); Tezcaner, Ayşen, E-mail: tezcaner@metu.edu.tr [Department of Engineering Sciences, Middle East Technical University (Turkey); Biomaterials and Tissue Engineering Center of Excellence, Middle East Technical University (Turkey)

    2016-12-01

    Natural polymer based fibrous scaffolds have been explored for bone tissue engineering applications; however, their inadequate 3-dimensionality and poor mechanical properties are among the concerns for their use as bone substitutes. In this study, pullulan (P) and cellulose acetate (CA), two polysaccharides, were electrospun at various P/CA ratios (P{sub 80}/CA{sub 20}, P{sub 50}/CA{sub 50}, and P{sub 20}/CA{sub 80}%) to develop 3D fibrous network. The scaffolds were then crosslinked with trisodium trimetaphosphate (STMP) to improve the mechanical properties and to delay fast weight loss. The lowest weight loss was observed for the groups that were crosslinked with P/STMP 2/1 for 10 min. Fiber morphologies of P{sub 50}/CA{sub 50} were more uniform without phase separation and this group was crosslinked most efficiently among groups. It was found that mechanical properties of P{sub 20}/CA{sub 80} and P{sub 50}/CA{sub 50} were higher than that of P{sub 80}/CA{sub 20.} After crosslinking strain values of P{sub 50}/CA{sub 50} scaffolds were improved and these scaffolds became more stable. Unlike P{sub 80}/CA{sub 20,} uncrosslinked P{sub 50}/CA{sub 50} and P{sub 20}/CA{sub 80} were not lost in PBS. Among all groups, crosslinked P{sub 50}/CA{sub 50} scaffolds had more uniform pores; therefore this group was used for bioactivity and cell culture studies. Apatite-like structures were observed on fibers after SBF incubation. Human Osteogenic Sarcoma Cell Line (Saos-2) seeded onto crosslinked P{sub 50}/CA{sub 50} scaffolds adhered and proliferated. The functionality of cells was tested by measuring ALP activity of the cells and the results indicated their osteoblastic differentiation. In vitro tests showed that scaffolds were cytocompatible. To sum up, crosslinked P{sub 50}/CA{sub 50} scaffolds were proposed as candidate cell carriers for bone tissue engineering applications. - Highlights: • Crosslinked 3D electrospun P/CA scaffolds were prepared for the first time. • CA

  11. Cell penetration to nanofibrous scaffolds

    Czech Academy of Sciences Publication Activity Database

    Rampichová, Michala; Buzgo, Matej; Chvojka, J.; Prosecká, Eva; Kofroňová, Olga; Amler, Evžen

    2014-01-01

    Roč. 8, č. 1 (2014), s. 36-41 ISSN 1933-6918 Grant - others:GA UK(CZ) 384311; GA UK(CZ) 626012; GA UK(CZ) 270513; GA UK(CZ) 330611; GA UK(CZ) 648112; GA MZd(CZ) NT12156; GA MŠk(CZ) project IPv6 Institutional support: RVO:68378041 ; RVO:61388971 Keywords : fibrous scaffold * mesenchymal stem cells * Forcespinning (R) Subject RIV: FP - Other Medical Disciplines Impact factor: 4.505, year: 2014

  12. Electrospun PLLA nanofiber scaffolds and their use in combination with BMP-2 for reconstruction of bone defects.

    Directory of Open Access Journals (Sweden)

    Markus D Schofer

    Full Text Available Adequate migration and differentiation of mesenchymal stem cells is essential for regeneration of large bone defects. To achieve this, modern graft materials are becoming increasingly important. Among them, electrospun nanofiber scaffolds are a promising approach, because of their high physical porosity and potential to mimic the extracellular matrix (ECM.The objective of the present study was to examine the impact of electrospun PLLA nanofiber scaffolds on bone formation in vivo, using a critical size rat calvarial defect model. In addition we analyzed whether direct incorporation of bone morphogenetic protein 2 (BMP-2 into nanofibers could enhance the osteoinductivity of the scaffolds. Two critical size calvarial defects (5 mm were created in the parietal bones of adult male Sprague-Dawley rats. Defects were either (1 left unfilled, or treated with (2 bovine spongiosa, (3 PLLA scaffolds alone or (4 PLLA/BMP-2 scaffolds. Cranial CT-scans were taken at fixed intervals in vivo. Specimens obtained after euthanasia were processed for histology, histomorphometry and immunostaining (Osteocalcin, BMP-2 and Smad5.PLLA scaffolds were well colonized with cells after implantation, but only showed marginal ossification. PLLA/BMP-2 scaffolds showed much better bone regeneration and several ossification foci were observed throughout the defect. PLLA/BMP-2 scaffolds also stimulated significantly faster bone regeneration during the first eight weeks compared to bovine spongiosa. However, no significant differences between these two scaffolds could be observed after twelve weeks. Expression of osteogenic marker proteins in PLLA/BMP-2 scaffolds continuously increased throughout the observation period. After twelve weeks osteocalcin, BMP-2 and Smad5 were all significantly higher in the PLLA/BMP-2 group than in all other groups.Electrospun PLLA nanofibers facilitate colonization of bone defects, while their use in combination with BMP-2 also increases bone

  13. An anisotropically and heterogeneously aligned patterned electrospun scaffold with tailored mechanical property and improved bioactivity for vascular tissue engineering.

    Science.gov (United States)

    Xu, He; Li, Haiyan; Ke, Qinfei; Chang, Jiang

    2015-04-29

    The development of vascular scaffolds with controlled mechanical properties and stimulatory effects on biological activities of endothelial cells still remains a significant challenge to vascular tissue engineering. In this work, we reported an innovative approach to prepare a new type of vascular scaffolds with anisotropically and heterogeneously aligned patterns using electrospinning technique with unique wire spring templates, and further investigated the structural effects of the patterned electrospun scaffolds on mechanical properties and angiogenic differentiation of human umbilical vein endothelial cells (HUVECs). Results showed that anisotropically aligned patterned nanofibrous structure was obtained by depositing nanofibers on template in a structurally different manner, one part of nanofibers densely deposited on the embossments of wire spring and formed cylindrical-like structures in the transverse direction, while others loosely suspended and aligned along the longitudinal direction, forming a three-dimensional porous microstructure. We further found that such structures could efficiently control the mechanical properties of electrospun vascular scaffolds in both longitudinal and transverse directions by altering the interval distances between the embossments of patterned scaffolds. When HUVECs were cultured on scaffolds with different microstructures, the patterned scaffolds distinctively promoted adhesion of HUVECs at early stage and proliferation during the culture period. Most importantly, cells experienced a large shape change associated with cell cytoskeleton and nuclei remodeling, leading to a stimulatory effect on angiogenesis differentiation of HUVECs by the patterned microstructures of electrospun scaffolds, and the scaffolds with larger distances of intervals showed a higher stimulatory effect. These results suggest that electrospun scaffolds with the anisotropically and heterogeneously aligned patterns, which could efficiently control the

  14. Improving PEEK bioactivity for craniofacial reconstruction using a 3D printed scaffold embedded with mesenchymal stem cells.

    Science.gov (United States)

    Roskies, Michael; Jordan, Jack O; Fang, Dongdong; Abdallah, Mohamed-Nur; Hier, Michael P; Mlynarek, Alex; Tamimi, Faleh; Tran, Simon D

    2016-07-01

    Polyetheretherketone (PEEK) is a bioinert thermoplastic that has been investigated for its potential use in craniofacial reconstruction; however, its use in clinical practice is limited by a poor integration with adjacent bone upon implantation. To improve the bone-implant interface, two strategies have been employed: to modify its surface or to impregnate PEEK with bioactive materials. This study attempts to combine and improve upon the two approaches by modifying the internal structure into a trabecular network and to impregnate PEEK with mesenchymal stem cells. Furthermore, we compare the newly designed PEEK scaffolds' interactions with both bone-derived (BMSC) and adipose (ADSC) stem cells. Customized PEEK scaffolds were designed to incorporate a trabecular microstructure using a computer-aided design program and then printed via selective laser sintering (SLS), a 3D-printing process with exceptional accuracy. The scaffold structure was evaluated using microCT. Scanning electron microscopy (SEM) was used to evaluate scaffold morphology with and without mesenchymal stem cells (MSCs). Adipose and bone marrow mesenchymal cells were isolated from rats and cultured on scaffolds. Cell proliferation and differentiation were assessed using alamarBlue and alkaline phosphatase assays, respectively. Cell morphology after one week of co-culturing cells with PEEK scaffolds was evaluated using SEM. SLS 3D printing fabricated scaffolds with a porosity of 36.38% ± 6.66 and density of 1.309 g/cm(2). Cell morphology resembled viable fibroblasts attaching to the surface and micropores of the scaffold. PEEK scaffolds maintained the viability of both ADSCs and BMSCs; however, ADSCs demonstrated higher osteodifferentiation than BMSCs (p PEEK scaffolds that maintain the viability of adipose and bone marrow-derived MSCs and induce the osteodifferentiation of the adipose-derived MSCs. The combination of 3D printed PEEK scaffolds with MSCs could overcome some of the limitations

  15. Tantalum coating on porous Ti6Al4V scaffold using chemical vapor deposition and preliminary biological evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang, E-mail: xiangliwj@sjtu.edu.cn [School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, 200240 (China); Wang, Lin [Institute of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi' an, 710032 (China); Yu, Xiaoming [The Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China); Feng, Yafei [Institute of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi' an, 710032 (China); Wang, Chengtao [School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, 200240 (China); Yang, Ke [The Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China); Su, Daniel [School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, 200240 (China)

    2013-07-01

    Porous tantalum (Ta), produced via chemical vapor deposition (CVD) of commercially pure Ta onto a vitreous carbon, is currently available for use in orthopedic applications. However, the relatively high manufacturing cost and the incapability to produce customized implant using medical image data have limited its application to gain widespread acceptance. In this study, Ta film was deposited on porous Ti6Al4V scaffolds using CVD technique. Digital microscopy and scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure. X-ray diffraction analysis showed that the coating consisted of α and β phases of Ta. Goat mesenchymal stem cells were seeded and cultured on the Ti6Al4V scaffolds with and without coating. The tetrazolium-based colorimetric assay exhibited better cell adhesion and proliferation on Ta-coated scaffolds compared with uncoated scaffolds. The porous scaffolds were subsequently implanted in goats for 12 weeks. Histological analysis revealed similar bone formation around the periphery of the coated and uncoated implants, but bone ingrowth is better within the Ta-coated scaffolds. To demonstrate the ability of producing custom implant for clinical applications via this technology, we designed and fabricated a porous Ti6Al4V scaffold with segmental mandibular shape derived from patient computerized tomography data. - Highlights: • Ta film was coated on porous Ti6Al4V scaffold using chemical vapor deposition. • Tantalum coating allowed for higher levels of cell adhesion and proliferation. • Better new bone formation occurred inside the tantalum-coated scaffolds. • Clinical image data was integrated with EBM to fabricate customized scaffold.

  16. Tantalum coating on porous Ti6Al4V scaffold using chemical vapor deposition and preliminary biological evaluation

    International Nuclear Information System (INIS)

    Li, Xiang; Wang, Lin; Yu, Xiaoming; Feng, Yafei; Wang, Chengtao; Yang, Ke; Su, Daniel

    2013-01-01

    Porous tantalum (Ta), produced via chemical vapor deposition (CVD) of commercially pure Ta onto a vitreous carbon, is currently available for use in orthopedic applications. However, the relatively high manufacturing cost and the incapability to produce customized implant using medical image data have limited its application to gain widespread acceptance. In this study, Ta film was deposited on porous Ti6Al4V scaffolds using CVD technique. Digital microscopy and scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure. X-ray diffraction analysis showed that the coating consisted of α and β phases of Ta. Goat mesenchymal stem cells were seeded and cultured on the Ti6Al4V scaffolds with and without coating. The tetrazolium-based colorimetric assay exhibited better cell adhesion and proliferation on Ta-coated scaffolds compared with uncoated scaffolds. The porous scaffolds were subsequently implanted in goats for 12 weeks. Histological analysis revealed similar bone formation around the periphery of the coated and uncoated implants, but bone ingrowth is better within the Ta-coated scaffolds. To demonstrate the ability of producing custom implant for clinical applications via this technology, we designed and fabricated a porous Ti6Al4V scaffold with segmental mandibular shape derived from patient computerized tomography data. - Highlights: • Ta film was coated on porous Ti6Al4V scaffold using chemical vapor deposition. • Tantalum coating allowed for higher levels of cell adhesion and proliferation. • Better new bone formation occurred inside the tantalum-coated scaffolds. • Clinical image data was integrated with EBM to fabricate customized scaffold

  17. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Ruixin [Institute of Medical Equipment, Academy of Military and Medical Sciences, No. 106, Wandong Street, Hedong District, Tianjin 300000 (China); Jiang, Wenxue, E-mail: jiangortholivea@sina.cn [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Sun, Yufu [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Hui [Tianjin Medical University General Hospital, No. 154 Anshan Road, Tianjin, TJ 300052 (China)

    2016-09-02

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  18. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    International Nuclear Information System (INIS)

    Sun, Kai; Li, Ruixin; Jiang, Wenxue; Sun, Yufu; Li, Hui

    2016-01-01

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  19. Mortgaged Minds: Faculty-in-Debt and Redlining Higher Education

    Directory of Open Access Journals (Sweden)

    Jeanne Scheper

    2017-02-01

    Full Text Available While undergraduate student loan debt continues to be “hard to register,” there are other conditions and effects of the student loan debt spiral that remain relatively invisible, unexamined, and certainly receive less attention in news headlines or on the op-ed pages about the fiscal cliff of education debt. These are the effects of this debt spiral on graduate education, faculty composition, and knowledge production itself. This article highlights how the debt load of faculty is part of the current student loan debt spiral, yet its effects on the working conditions of faculty, the learning conditions of students, and, importantly, the production of knowledge in the university remain underexamined.

  20. Recombinant protein scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Werkmeister, Jerome A; Ramshaw, John A M

    2012-01-01

    New biological materials for tissue engineering are now being developed using common genetic engineering capabilities to clone and express a variety of genetic elements that allow cost-effective purification and scaffold fabrication from these recombinant proteins, peptides or from chimeric combinations of these. The field is limitless as long as the gene sequences are known. The utility is dependent on the ease, product yield and adaptability of these protein products to the biomedical field. The development of recombinant proteins as scaffolds, while still an emerging technology with respect to commercial products, is scientifically superior to current use of natural materials or synthetic polymer scaffolds, in terms of designing specific structures with desired degrees of biological complexities and motifs. In the field of tissue engineering, next generation scaffolds will be the key to directing appropriate tissue regeneration. The initial period of biodegradable synthetic scaffolds that provided shape and mechanical integrity, but no biological information, is phasing out. The era of protein scaffolds offers distinct advantages, particularly with the combination of powerful tools of molecular biology. These include, for example, the production of human proteins of uniform quality that are free of infectious agents and the ability to make suitable quantities of proteins that are found in low quantity or are hard to isolate from tissue. For the particular needs of tissue engineering scaffolds, fibrous proteins like collagens, elastin, silks and combinations of these offer further advantages of natural well-defined structural scaffolds as well as endless possibilities of controlling functionality by genetic manipulation. (topical review)

  1. Scaffolding Mathematical Modelling with a Solution Plan

    Science.gov (United States)

    Schukajlow, Stanislaw; Kolter, Jana; Blum, Werner

    2015-01-01

    In the study presented in this paper, we examined the possibility to scaffold mathematical modelling with strategies. The strategies were prompted using an instrument called "solution plan" as a scaffold. The effects of this step by step instrument on mathematical modelling competency and on self-reported strategies were tested using…

  2. Scaffolding proteins: not such innocent bystanders.

    Science.gov (United States)

    Smith, F Donelson; Scott, John D

    2013-06-17

    Sequential transfer of information from one enzyme to the next within the confines of a protein kinase scaffold enhances signal transduction. Though frequently considered to be inert organizational elements, two recent reports implicate kinase-scaffolding proteins as active participants in signal relay. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Scaffolding Proteins: Not Such Innocent Bystanders

    OpenAIRE

    Smith, F. Donelson; Scott, John D.

    2013-01-01

    Sequential transfer of information from one enzyme to the next within the confines of a protein kinase scaffold enhances signal transduction. Though frequently considered to be inert organizational elements, two recent reports implicate kinase-scaffolding proteins as active participants in signal relay.

  4. Metacognitive Scaffolding in an Innovative Learning Arrangement

    Science.gov (United States)

    Molenaar, Inge; van Boxtel, Carla A. M.; Sleegers, Peter J. C.

    2011-01-01

    This study examined the effects of metacognitive scaffolds on learning outcomes of collaborating students in an innovative learning arrangement. The triads were supported by computerized scaffolds, which were dynamically integrated into the learning process and took a structuring or problematizing form. In an experimental design the two…

  5. Teaching language teachers scaffolding professional learning

    CERN Document Server

    Maggioli, Gabriel Diaz

    2012-01-01

    Teaching Language Teachers: Scaffolding Professional Learning provides an updated view of as well as a reader-friendly introduction to the field of Teaching Teachers, with special reference to language teaching. By taking a decidedly Sociocultural perspective, the book addresses the main role of the Teacher of Teachers (ToT) as that of scaffolding the professional learning of aspiring teachers.

  6. A longitudinal investigation of the relationship between maternal mind-mindedness and theory of mind.

    Science.gov (United States)

    Kirk, Elizabeth; Pine, Karen; Wheatley, Lisa; Howlett, Neil; Schulz, Joerg; Fletcher, Ben C

    2015-11-01

    Data are presented from a longitudinal investigation examining the relationship between maternal mind-mindedness (MM) in infancy and socio-cognitive development in childhood. We revisited children (n = 18) who had taken part in a longitudinal study as infants. MM had been assessed at 10, 12, 16, and 20 months of age. We followed up these children at 5-6 years of age to test their higher order theory of mind (ToM) (using the strange stories task). The convergent validity, temporal stability, and predictive validity of the construct of MM were examined in a longitudinal data set. The five measures of MM were not significantly correlated. Mother's production of appropriate mind-related comments (but no other measures) showed evidence of temporal stability throughout infancy. Thus, MM (as measured by appropriate mind-related comments) was confirmed as a stable construct. Children's ToM at 5-6 years of age was significantly predicted by their mother's MM up to 4 years earlier, with MM accounting for 40% of the variance of the strange stories task scores. These findings identify a relationship between MM across a protracted period of infancy and socio-cognitive development at 5-6 years of age. © 2015 The British Psychological Society.

  7. Structural and degradation characteristics of an innovative porous PLGA/TCP scaffold incorporated with bioactive molecular icaritin

    Energy Technology Data Exchange (ETDEWEB)

    Xie Xinhui; Wang Xinluan; Zhang Ge; He Yixin; Liu Zhong; Peng Jiang; Qin Ling [Department of Orthopaedics and Traumatology, Chinese University of Hong Kong (Hong Kong); Wang Xiaohong; He Kai [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education and Center of Organ Manufacturing, Department of Mechanical Engineering, Tsinghua University, Beijing (China); Leng Yang, E-mail: lingqin@cuhk.edu.h [Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2010-10-01

    Phytomolecules may chemically bind to scaffold materials for medical applications. The present study used an osteoconductive porous poly(l-lactide-co-glycolide)/tricalcium phosphate (PLGA/TCP) to incorporate an exogenous phytoestrogenic molecule icaritin to form a PLGA/TCP/icaritin composite scaffold material with potential slow release of icaritin during scaffold degradation. Accordingly, the present study was designed to investigate its in vitro degradation characteristics and the release pattern of icaritin at three different doses (74 mg, 7.4 mg and 0.74 mg per 100 g PLGA/TCP, i.e. in the PLGA/TCP/icaritin-H, -M and -L groups, respectively). A PLGA/TCP/icaritin porous composite scaffold was fabricated using a computer-controlled printing machine. The PLGA/TCP/icaritin scaffolds were incubated in saline at 37 {sup 0}C for 12 weeks and the pure PLGA/TCP scaffold served as a control. During the 12 weeks in vitro degradation, the scaffolds in all four groups showed changes, including a decrease in weight, volume and pore size of the composite scaffold, while there was a decrease in acidity and an increase in Ca and lactic acid concentrations in the degradation medium, especially after 7 weeks. The rate of degradation was explained by the relationship with the content of icaritin incorporated into the scaffolds. The higher the icaritin content in the scaffolds, the slower the degradation could be observed during 12 weeks. After 12 weeks, the SEM showed that the surface of the PLGA/TCP and PLGA/TCP/icaritin-L groups was relatively smooth with a gradual decrease in number and size of the micropores, while the porous morphology on the surface of the PLGA/TCP/icaritin-M and PLGA/TCP/icaritin-H groups was partly maintained, accompanied by a decrease in phosphate (P) and calcium (Ca) contents at the surface. Though the mechanical property of the PLGA/TCP/icaritin scaffold decreased after degradation, its porous structure was maintained, which was essential for cell

  8. Mindfulness predicts student nurses' communication self-efficacy: A cross-national comparative study.

    Science.gov (United States)

    Sundling, Vibeke; Sundler, Annelie J; Holmström, Inger K; Kristensen, Dorte Vesterager; Eide, Hilde

    2017-08-01

    The aim of this study was to compare student nurses' communication self-efficacy, empathy, and mindfulness across two countries, and to analyse the relationship between these qualities. The study had a cross-sectional design. Data was collected from final year student nurses in Norway and Sweden. Communication self-efficacy, empathy, and mindfulness were reported by questionnaires; Clear-cut communication with patients, Jefferson Scale of Empathy, and Langer 14 items mindfulness scale. The study included 156 student nurses, 94 (60%) were Swedish. The mean communication self-efficacy score was 119 (95% CI 116-122), empathy score 115 (95% CI 113-117) and mindfulness score 79 (95% CI 78-81). A Mann-Whitney test showed that Swedish students scored significantly higher on communication self-efficacy, empathy, and mindfulness than Norwegian students did. When adjusted for age, gender, and country in a multiple linear regression, mindfulness was the only independent predictor of communication self-efficacy. The Swedish student nurses in this study scored higher on communication self-efficacy, empathy, and mindfulness than Norwegian students did. Student nurses scoring high on mindfulness rated their communication self-efficacy higher. A mindful learning approach may improve communication self-efficacy and possibly the effect of communication skills training. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Dispositional Mindfulness Co-Varies with Smaller Amygdala and Caudate Volumes in Community Adults

    Science.gov (United States)

    Taren, Adrienne A.; Creswell, J. David; Gianaros, Peter J.

    2013-01-01

    Mindfulness, a psychological process reflecting attention and awareness to what is happening in the present moment, has been associated with increased well-being and decreased depression and anxiety in both healthy and patient populations. However, little research has explored underlying neural pathways. Recent work suggests that mindfulness (and mindfulness training interventions) may foster neuroplastic changes in cortico-limbic circuits responsible for stress and emotion regulation. Building on this work, we hypothesized that higher levels of dispositional mindfulness would be associated with decreased grey matter volume in the amgydala. In the present study, a self-report measure of dispositional mindfulness and structural MRI images were obtained from 155 healthy community adults. Volumetric analyses showed that higher dispositional mindfulness is associated with decreased grey matter volume in the right amygdala, and exploratory analyses revealed that higher dispositional mindfulness is also associated with decreased grey matter volume in the left caudate. Moreover, secondary analyses indicate that these amygdala and caudate volume associations persist after controlling for relevant demographic and individual difference factors (i.e., age, total grey matter volume, neuroticism, depression). Such volumetric differences may help explain why mindful individuals have reduced stress reactivity, and suggest new candidate structural neurobiological pathways linking mindfulness with mental and physical health outcomes. PMID:23717632

  10. Dispositional mindfulness co-varies with smaller amygdala and caudate volumes in community adults.

    Directory of Open Access Journals (Sweden)

    Adrienne A Taren

    Full Text Available Mindfulness, a psychological process reflecting attention and awareness to what is happening in the present moment, has been associated with increased well-being and decreased depression and anxiety in both healthy and patient populations. However, little research has explored underlying neural pathways. Recent work suggests that mindfulness (and mindfulness training interventions may foster neuroplastic changes in cortico-limbic circuits responsible for stress and emotion regulation. Building on this work, we hypothesized that higher levels of dispositional mindfulness would be associated with decreased grey matter volume in the amgydala. In the present study, a self-report measure of dispositional mindfulness and structural MRI images were obtained from 155 healthy community adults. Volumetric analyses showed that higher dispositional mindfulness is associated with decreased grey matter volume in the right amygdala, and exploratory analyses revealed that higher dispositional mindfulness is also associated with decreased grey matter volume in the left caudate. Moreover, secondary analyses indicate that these amygdala and caudate volume associations persist after controlling for relevant demographic and individual difference factors (i.e., age, total grey matter volume, neuroticism, depression. Such volumetric differences may help explain why mindful individuals have reduced stress reactivity, and suggest new candidate structural neurobiological pathways linking mindfulness with mental and physical health outcomes.

  11. Manipulation of chemical composition and architecture of non-biodegradable poly(ethylene terephthalate)/chitosan fibrous scaffolds and their effects on L929 cell behavior

    International Nuclear Information System (INIS)

    Veleirinho, Beatriz; Berti, Fernanda V.; Dias, Paulo F.; Maraschin, Marcelo; Ribeiro-do-Valle, Rosa M.; Lopes-da-Silva, José A.

    2013-01-01

    Microporous, non-woven fibrous scaffolds made of poly(ethylene terephthalate) and chitosan were produced by electrospinning. Fiber morphology, diameter, pore size, and wettability were manipulated by varying the chemical composition of the electrospinning solution, i.e. chitosan concentration and molecular weight, and by post-electrospinning treatment with glutaraldehyde. In vitro studies were conducted using a fibroblast cell line toward a comprehensive understanding of how scaffolds characteristics can modulate the cell behavior, i.e. viability, adhesion, proliferation, extracellular matrix secretion, and three-dimensional colonization. Substantial differences were found as a result of scaffold morphological changes. Higher levels of adhesion, spreading, and superficial proliferation were achieved for scaffolds with smaller fiber and pore diameters while cell penetration and internal colonization were enhanced for scaffolds with larger pores. Additionally, the available area for cell adhesion, which is related to fiber and pore size, was a crucial factor for the viability of L929 cells. This paper provides significant insights for the development and optimization of electrospun scaffolds toward an improved biological performance. Highlights: ► Hybrid PET/chitosan mats were produced by electrospinning. ► Scaffold architecture was manipulated by changing composition of the spun solution. ► The scaffolds showed in vitro biocompatibility to L929 cells. ► Smaller fiber diameters and pore areas allowed for higher levels of cell adhesion and proliferation. ► A 3D cell colonization was achieved for scaffolds with higher fiber diameters.

  12. Osteoconductivity and Biodegradability of Collagen Scaffold Coated with Nano-β-TCP and Fibroblast Growth Factor 2

    Directory of Open Access Journals (Sweden)

    Asako Ibara

    2013-01-01

    Full Text Available Nanoparticle bioceramics have become anticipated for biomedical applications. Highly bioactive and biodegradable scaffolds would be developed using nanoparticles of β-tricalcium phosphate (β-TCP. We prepared collagen scaffolds coated by nano-β-TCP and fibroblast growth factor 2 (FGF2 and evaluated the effects on new bone augmentation and biodegradation. The collagen sponge was coated with the nano-TCP dispersion and freeze-dried. Scaffold was characterized by SEM, TEM, XRD, compressive testing and cell seeding. Subsequently, the nano-β-TCP/collagen scaffold, collagen sponge, and each material loaded with FGF2 were implanted on rat cranial bone. As a control, no implantation was performed. Nano-TCP particles were found to be attached to the fibers of the collagen sponge by SEM and TEM observations. Scaffold coated with nano-TCP showed higher compressive strength and cytocompatibility. In histological evaluations at 10 days, inflammatory cells were rarely seen around the residual scaffold, suggesting that the nano-TCP material possesses good tissue compatibility. At 35 days, bone augmentation and scaffold degradation in histological samples receiving nano-β-TCP scaffold were significantly greater than those in the control. By loading of FGF2, advanced bone formation is facilitated, indicating that a combination with FGF2 would be effective for bone tissue engineering.

  13. Binary phase solid-state photopolymerization of acrylates: design, characterization and biomineralization of 3D scaffolds for tissue engineering

    Science.gov (United States)

    Maitlo, Inamullah; Ali, Safdar; Akram, Muhammad Yasir; Shehzad, Farooq Khurum; Nie, Jun

    2017-12-01

    Porous polymer scaffolds designed by the cryogel method are attractive materials for a range of tissue engineering applications. However, the use of toxic crosslinker for retaining the pore structure limits their clinical applications. In this research, acrylates (HEA/PEGDA, HEMA/PEGDA and PEGDA) were used in the low-temperature solid-state photopolymerization to produce porous scaffolds with good structural retention. The morphology, pore diameter, mineral deposition and water absorption of the scaffold were characterized by SEM and water absorption test respectively. Elemental analysis and cytotoxicity of the biomineralized scaffold were revealed by using XRD and MTT assay test. The PEGDA-derived scaffold showed good water absorption ability and a higher degree of porosity with larger pore size compared to others. XRD patterns and IR results confirmed the formation of hydroxyapatite crystals from an alternative socking process. The overall cell proliferation was excellent, where PEGDA-derived scaffold had the highest and the most uniform cell growth, while HEMA/PEGDA scaffold showed the least. These results suggest that the cell proliferation and adhesion are directly proportional to the pore size, the shape and the porosity of scaffolds.

  14. Mag-seeding of rat bone marrow stromal cells into porous hydroxyapatite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Shimizu, Kazunori; Ito, Akira; Honda, Hiroyuki

    2007-09-01

    Bone tissue engineering has been investigated as an alternative strategy for autograft transplantation. In the process of tissue engineering, cell seeding into three-dimensional (3-D) scaffolds is the first step for constructing 3-D tissues. We have proposed a methodology of cell seeding into 3-D porous scaffolds using magnetic force and magnetite nanoparticles, which we term Mag-seeding. In this study, we applied this Mag-seeding technique to bone tissue engineering using bone marrow stromal cells (BMSCs) and 3-D hydroxyapatite (HA) scaffolds. BMSCs were magnetically labeled with our original magnetite cationic liposomes (MCLs) having a positive surface charge to improve adsorption to cell surface. Magnetically labeled BMSCs were seeded onto a scaffold, and a 1-T magnet was placed under the scaffold. By using Mag-seeding, the cells were successfully seeded into the internal space of scaffolds with a high cell density. The cell seeding efficiency into HA scaffolds by Mag-seeding was approximately threefold larger than that by static-seeding (conventional method, without a magnet). After a 14-d cultivation period using the osteogenic induction medium by Mag-seeding, the level of two representative osteogenic markers (alkaline phosphatase and osteocalcin) were significantly higher than those by static-seeding. These results indicated that Mag-seeding of BMSCs into HA scaffolds is an effective approach to bone tissue engineering.

  15. Physicochemical properties and enhanced cellullar responses of biocompatible polymeric scaffolds treated with atmospheric pressure plasma using O{sub 2} gas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun-Uk; Park, So-Young; Kang, Yoon-Hee [Department of Nano Fusion Technology, Pusan National University, Busan 609735 (Korea, Republic of); Jeong, Se-Young [Division of Cogni-mechatronics Engineering, Pusan National University, Miryang 627706 (Korea, Republic of); Choi, Sae-Hae; Jahng, Yoon-Young; Chung, Gook-Hyun [Division of Biological Sciences, Chonbuk National University, Jeonju 561756 (Korea, Republic of); Kim, Moon-Bum [Department of Dermatology, School of Medicine, Pusan National University, Busan (Korea, Republic of); Cho, Chae-Ryong, E-mail: crcho@pusan.ac.kr [Department of Nano Fusion Technology, Pusan National University, Busan 609735 (Korea, Republic of)

    2011-04-08

    Biocompatible polymeric scaffolds were fabricated by mixing 5 wt.% poly({epsilon}-caprolactone) (P) with 4 wt.% gelatin (G) and 1.6 wt.% Dulbecco's modified Eagle's medium containing 10% fetal bovine serum (D). These PGD scaffolds were also treated with atmospheric pressure (AP) plasma using O{sub 2} reactive gas (to create O-PGD scaffolds). The physicochemical and mechanical properties of the PGD scaffolds were characterized by in vitro biodegradability tests, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, contact angle measurements, and tensile strength measurements. The wettability and hydrophilic properties of the scaffold surface were improved remarkably by adding G and D to P, and by subsequent oxygen-assisted AP plasma treatment. An MTT assay, a cell attachment efficiency assay, scanning electron microscopy, and confocal microscopy revealed that Chinese Hamster Ovary (CHO)-K1 cells exhibited higher cell attachment and viability on the PGD and O-PGD scaffolds than on the P and PG scaffolds. Furthermore, the long-term viability of the CHO cells on the PGD and O-PGD scaffolds without exchanging the cell culture media was significantly improved compared to their viability on the P and PG scaffolds. Overall, the PGD and O-PGD scaffolds are expected to be useful as cell growth supporting biomaterials in tissue engineering.

  16. Preparation, characterization and biological test of 3D-scaffolds based on chitosan, fibroin and hydroxyapatite for bone tissue engineering

    International Nuclear Information System (INIS)

    Lima, Paulo Autran Leite; Resende, Cristiane Xavier; Dulce de Almeida Soares, Glória; Anselme, Karine; Almeida, Luís Eduardo

    2013-01-01

    This work describes the preparation and characterization of porous 3D-scaffolds based on chitosan (CHI), chitosan/silk fibroin (CHI/SF) and chitosan/silk fibroin/hydroxyapatite (CHI/SF/HA) by freeze drying. The biomaterials were characterized by X-ray diffraction, attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy and energy dispersive spectroscopy. In addition, studies of porosity, pore size, contact angle and biological response of SaOs-2osteoblastic cells were performed. The CHI scaffolds have a porosity of 94.2 ± 0.9%, which is statistically higher than the one presented by CHI/SF/HA scaffolds, 89.7 ± 2.6%. Although all scaffolds were able to promote adhesion, growth and maintenance of osteogenic differentiation of SaOs-2 cells, the new 3D-scaffold based on CHI/SF/HA showed a significantly higher cell growth at 7 days and 21 days and the level of alkaline phosphatase at 14 and 21 days was statistically superior compared to other tested materials. - Highlights: • Preparation of 3D-scaffolds based on CHI, with or without addition of SF and HA. • Scaffolds exhibited interconnected porous structure (pore size superior to 50 μm). • The tripolyphosphate did not induce any significant cytotoxic response. • The CHI/SF/HA composite showed a higher cell growth and ALP activity

  17. The assessment of mindfulness skills: the "what" and the "how".

    Science.gov (United States)

    Iani, Luca; Lauriola, Marco; Cafaro, Valentina

    2017-10-06

    The five facets mindfulness questionnaire-short form (FFMQ-SF) is a new, brief measure for the assessment of mindfulness skills in clinical and nonclinical samples. The construct validity of the FFMQ-SF has not been previously assessed in community samples. The present study investigated the factor structure of the Italian version of the FFMQ-SF. Structured equation modeling was used to test the fit of three alternative models in a sample of highly educated adults (n = 211). A hierarchical model with a single second-order factor loaded by observing, describing, and acting with awareness (i.e. the mindfulness "what" skills) performed slightly better than both a five-factor model with correlated factors and a hierarchical model with a general second-order factor. The FFMQ-SF scores were significantly higher than those reported in both Dutch depressed patients and Australian undergraduate students for all facets (but nonreactivity for the Australian sample). Data support the multifaceted nature of mindfulness skills. Because of its brevity and simplicity of use, the FFMQ-SF is a promising questionnaire in longitudinal and clinical research. This questionnaire can serve as a guideline to help clinicians assess and monitor mindfulness skills acquisition, strengthening, and generalization, and prioritize mindfulness skills that need immediate attention.

  18. Mindful Parenting and Emotion Socialization Practices: Concurrent and Longitudinal Associations.

    Science.gov (United States)

    McKee, Laura G; Parent, Justin; Zachary, Chloe R; Forehand, Rex

    2017-11-01

    Caregivers play a crucial role in the socialization of youth emotion understanding, competence, and regulation, which are implicated in youth social and emotional health; however, there is less understanding of parental psychosocial or cognitive factors, like mindful parenting, that may be associated with the use of particular emotion socialization (ES) strategies. This study tests a model of the cross-sectional and short-term longitudinal associations between mindful parenting and supportive and nonsupportive ES strategies in a community sample of parents (N = 246; 63.8% mothers) of youth ranging from ages 3-12. Caregivers reported on mindful parenting and ES strategies at two time points 4 months apart. The structural equation model indicated that higher levels of mindful parenting are positively related to supportive ES responses and negatively related to nonsupportive ES responses both concurrently and over time. The longitudinal association between mindful parenting and nonsupportive, but not supportive, ES was marginally larger for fathers as compared to mothers. Given the documented impact of ES strategies on youth emotional and behavioral outcomes and interventions emerging to educate parents about how to provide a healthy emotional atmosphere, incorporating a focus on mindful parenting strategies may provide one pathway to increase supportive responses and decrease nonsupportive ones. © 2017 Family Process Institute.

  19. The oceanic literary reading mind : An impression

    NARCIS (Netherlands)

    Burke, M.

    2016-01-01

    The mind and brain processes of the literary reading mind are most accurately defined as oceanic: the mind is an ocean. This is the essential premise that I put forward in my book Literary Reading, Cognition and Emotion: An Exploration of the Oceanic Mind (Routledge, 2011).1 The statement is of

  20. Brief Mindfulness Meditation Training Reduces Mind-Wandering: The Critical Role of Acceptance

    Science.gov (United States)

    Rahl, Hayley A.; Lindsay, Emily K.; Pacilio, Laura E.; Brown, Kirk W.; Creswell, J. David

    2016-01-01

    Mindfulness meditation programs, which train individuals to monitor their present moment experience in an open or accepting way, have been shown to reduce mind-wandering on standardized tasks in several studies. Here we test two competing accounts for how mindfulness training reduces mind-wandering, evaluating whether the attention monitoring component of mindfulness training alone reduces mind-wandering or whether the acceptance training component is necessary for reducing mind-wandering. Healthy young adults (N=147) were randomized to either a 3-day brief mindfulness training condition incorporating instruction in both attention monitoring and acceptance, a mindfulness training condition incorporating attention monitoring instruction only, a relaxation training condition, or a reading control condition. Participants completed measures of dispositional mindfulness and treatment expectancies before the training session on Day 1 and then completed a 6-minute Sustained Attention Response Task (SART) measuring mind-wandering after the training session on Day 3. Acceptance training was important for reducing mind-wandering, such that the monitoring + acceptance mindfulness training condition had the lowest mind-wandering relative to the other conditions, including significantly lower mind-wandering relative to the monitor-only mindfulness training condition. In one of the first experimental mindfulness training dismantling studies to-date, we show that training in acceptance is a critical driver of mindfulness training reductions in mind-wandering. This effect suggests that acceptance skills may facilitate emotion regulation on boring and frustrating sustained attention tasks that foster mind-wandering, such as the SART. PMID:27819445

  1. Understanding the role of mind wandering in stress-related working memory impairments.

    Science.gov (United States)

    Banks, Jonathan B; Boals, Adriel

    2017-08-01

    Mind wandering has been identified as a possible cause for stress-related working memory (WM) task impairments following laboratory stressors. The current study attempted to induce mind wandering regarding negative, positive, or neutral events using an expressive writing task and examined the impact on WM task performance. We examined the role of mind wandering in understanding the impact of life stress on WM. Additionally, we explored the role of thought suppression on the relationship between mind wandering and WM. One hundred and fifty participants completed WM measures before (Time 1) and after (Time 2) the writing manipulation. The writing manipulation did not alter mind wandering or WM task performance. Time 1 WM predicted mind wandering during the Time 2 WM task, which subsequently predicted poorer Time 2 WM task performance. The impact of daily life stress on WM was mediated by mind wandering. Trait levels of thought suppression moderated the impact of mind wandering on WM. Specifically, higher levels of suppression resulted in stronger negative impact of mind wandering on WM task performance. Findings are discussed in terms of the impact of mind wandering on WM task performance.

  2. [Mentalization and theory of mind].

    Science.gov (United States)

    Wyl, Agnes

    2014-01-01

    Both concepts, mentalization and the theory of mind, describe metacognitive processes. Mentalization mainly concerns the reflection of affective mental states. In contrast, theory of mind focuses on epistemic states such as beliefs, intentions and persuasions. Gender differences have proved to be relevant for both, the development of mentalization and the theory of mind. However, there are few studies and findings are inconsistent. In an own study, we investigated the relationship between early competences in metacognition (tested in a false-belief-task second order) and narrative skills of kindergarten children. Results show that children who had successfully passed the theory of mind test tended to face conflicts more directly in the stories. In consequence, these children showed less narrative avoidance. However, differences were only found in girls and not in boys. The precise understanding of developmental differences in metacognition between girls and boys may be an important aspect with regards to improving mentalization based therapy of children.

  3. Distributed scaffolding: Wiki collaboration among Latino high school chemistry students

    Science.gov (United States)

    O'Sullivan, Edwin Duncan, Jr.

    -natural wiki project. Results suggested a higher frequency of metacognitive scaffolding by the teacher, over peers, for content knowledge and making connections knowledge. Teacher metacognitive scaffolding often took the form of posting discussion board questions designed to stimulate student reflection on their content or creativity. On the other hand, both teacher and peer metacognitive scaffolding for general goals knowledge and strategy knowledge was relatively infrequent. Recommendations are offered for improving teacher and peer metacognitive scaffolding.

  4. Patterns in the mind

    Directory of Open Access Journals (Sweden)

    Acosta Alejandro

    1999-06-01

    Full Text Available

     A mediados de la década de los noventa, el lingüista estadounidense Ray Jackendoff, meditando acerca de la situación de los avances en su campo de trabajo, publicó el libro Patterns in the Mind con el objetivo de poner al alcance del público no especializado los avances de la psicología cognitiva a partir de los postulados básicos de la revolución lingüística y cognitiva que
    floreció gracias a los trabajos del también lingüista norteamericano Noam Chomsky, a finales de la década de los cincuenta y principios de la de los sesenta. Su presencia en el desarrollo de esta nueva etapa del estudio del lenguaje y sus intereses en las nuevas teorías psicológicas 10 ubicaron en un marco teórico que comprende postulados acerca de la organización modular de las estructuras y procesos mentales, el innatismo de este tipo de organización y la existencia de una serie de patrones que rigen la construcción de gramáticas mentalesinconscientes para diversos dominios de la naturaleza humana.

  5. Relevance of fiber integrated gelatin-nanohydroxyapatite composite scaffold for bone tissue regeneration

    Science.gov (United States)

    Halima Shamaz, Bibi; Anitha, A.; Vijayamohan, Manju; Kuttappan, Shruthy; Nair, Shantikumar; Nair, Manitha B.

    2015-10-01

    Porous nanohydroxyapatite (nanoHA) is a promising bone substitute, but it is brittle, which limits its utility for load bearing applications. To address this issue, herein, biodegradable electrospun microfibrous sheets of poly(L-lactic acid)-(PLLA)-polyvinyl alcohol (PVA) were incorporated into a gelatin-nanoHA matrix which was investigated for its mechanical properties, the physical integration of the fibers with the matrix, cell infiltration, osteogenic differentiation and bone regeneration. The inclusion of sacrificial fibers like PVA along with PLLA and leaching resulted in improved cellular infiltration towards the center of the scaffold. Furthermore, the treatment of PLLA fibers with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide enhanced their hydrophilicity, ensuring firm anchorage between the fibers and the gelatin-HA matrix. The incorporation of PLLA microfibers within the gelatin-nanoHA matrix reduced the brittleness of the scaffolds, the effect being proportional to the number of layers of fibrous sheets in the matrix. The proliferation and osteogenic differentiation of human adipose-derived mesenchymal stem cells was augmented on the fibrous scaffolds in comparison to those scaffolds devoid of fibers. Finally, the scaffold could promote cell infiltration, together with bone regeneration, upon implantation in a rabbit femoral cortical defect within 4 weeks. The bone regeneration potential was significantly higher when compared to commercially available HA (Surgiwear™). Thus, this biomimetic, porous, 3D composite scaffold could be offered as a promising candidate for bone regeneration in orthopedics.

  6. Micro-CT based finite element models for elastic properties of glass-ceramic scaffolds.

    Science.gov (United States)

    Tagliabue, Stefano; Rossi, Erica; Baino, Francesco; Vitale-Brovarone, Chiara; Gastaldi, Dario; Vena, Pasquale

    2017-01-01

    In this study, the mechanical properties of porous glass-ceramic scaffolds are investigated by means of three-dimensional finite element models based on micro-computed tomography (micro-CT) scan data. In particular, the quantitative relationship between the morpho-architectural features of the obtained scaffolds, such as macroscopic porosity and strut thickness, and elastic properties, is sought. The macroscopic elastic properties of the scaffolds have been obtained through numerical homogenization approaches using the mechanical characteristics of the solid walls of the scaffolds (assessed through nanoindentation) as input parameters for the numerical simulations. Anisotropic mechanical properties of the produced scaffolds have also been investigated by defining a suitable anisotropy index. A comparison with morphological data obtained through the micro-CT scans is also presented. The proposed study shows that the produced glass-ceramic scaffolds exhibited a macroscopic porosity ranging between 29% and 97% which corresponds to an average stiffness ranging between 42.4GPa and 36MPa. A quantitative estimation of the isotropy of the macroscopic elastic properties has been performed showing that the samples with higher solid fractions were those closest to an isotropic material. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Carbon nanotubes reinforced poly(L-lactide) scaffolds fabricated by thermally induced phase separation

    International Nuclear Information System (INIS)

    Ma, Haiyun; Xue, Li

    2015-01-01

    In tissue engineering, porous nanocomposite scaffolds can potentially mimic aspects of the nanoscale architecture of the extra-cellular matrix, as well as enhance the mechanical properties required for successful weight-bearing implants. In this paper, we demonstrate that highly porous thermoplastic poly(L-lactide) nanocomposite scaffolds containing different types of functionalized multi-walled carbon nanotubes (CNTs). The nanocomposite scaffolds were manufactured by a thermally induced phase separation method. This experiment produced an uniform distribution of CNTs throughout the scaffold without obvious aggregations for funtionalized CNTs filled scaffolds by scanning electron microscope observation. The CNTs were frequently located on the pore surface, forming rough, hairy nano-textures. The pore size was reduced with the increasing of CNT loading. Parts of PLLA matrix was induced into nanofibrous structures from solid-walled state, which reduced the crystallinity of the PLLA characterized by DSC measurement. The CNT incorporation significantly improved the compression modulus of the nanocomposite scaffolds, especially the functionalized CNTs. The capacity of protein adsorption is significantly improved when the concentration of the CNTs was higher than 1.0 wt.% and the cell attachment was also enhanced by the addition of CNTs, especially N-CNT. (paper)

  8. Chitosan-based hydrogel tissue scaffolds made by 3D plotting promotes osteoblast proliferation and mineralization.

    Science.gov (United States)

    Liu, I-Hsin; Chang, Shih-Hsin; Lin, Hsin-Yi

    2015-05-13

    A 3D plotting system was used to make chitosan-based tissue scaffolds with interconnected pores using pure chitosan (C) and chitosan cross-linked with pectin (CP) and genipin (CG). A freeze-dried chitosan scaffold (CF/D) was made to compare with C, to observe the effects of structural differences. The fiber size, pore size, porosity, compression strength, swelling ratio, drug release efficacy, and cumulative weight loss of the scaffolds were measured. Osteoblasts were cultured on the scaffolds and their proliferation, type I collagen production, alkaline phosphatase activity, calcium deposition, and morphology were observed. C had a lower swelling ratio, degradation, porosity and drug release efficacy and a higher compressional stiffness and cell proliferation compared to CF/D (p 3D-plotted samples, cells on CP exhibited the highest degree of mineralization after 21 d (p 3D-plotted scaffolds were stronger, less likely to degrade and better promoted osteoblast cell proliferation in vitro compared to the freeze-dried scaffolds. C, CP and CG were structurally similar, and the different crosslinking caused significant changes in their physical and biological performances.

  9. The 3-D Culture and In Vivo Growth of the Human Hepatocellular Carcinoma Cell Line HepG2 in a Self-Assembling Peptide Nanofiber Scaffold

    International Nuclear Information System (INIS)

    Wu, M.; Yang, Z.; Liu, Y.; Liu, B.; Zhao, X.

    2010-01-01

    We report the use of the RADA16-I scaffold to mimic the ECM microenvironment and support tumor cell adherence and survival. Cellular morphology, proliferation, adhesion ability, and in vivo tumor formation were studied in the human hepatocellular carcinoma cell line HepG2 in the 3-D RADA16-I scaffold. No significant differences in HepG2 cell proliferation, adhesion, and albumin secretion were observed in the peptide scaffold compared to collagen I. Furthermore, the HepG2 cells pre cultured in the peptide scaffold showed a higher proliferation rate and formed significantly bigger tumors when compared to cells grown on a traditional 2D monolayer, suggesting that the 3-D RADA16-I scaffold can mimic the tumor microenvironment and promote a malignant phenotype in HepG2 cells. Our results indicate that the RADA16-I scaffold can serve as an ideal model for tumorigenesis, growth, local invasion, and metastasis.

  10. Effect of oxygen plasma etching on pore size-controlled 3D polycaprolactone scaffolds for enhancing the early new bone formation in rabbit calvaria.

    Science.gov (United States)

    Kook, Min-Suk; Roh, Hee-Sang; Kim, Byung-Hoon

    2018-05-02

    This study was to investigate the effects of O 2 plasma-etching of the 3D polycaprolactone (PCL) scaffold surface on preosteoblast cell proliferation and differentiation, and early new bone formation. The PCL scaffolds were fabricated by 3D printing technique. After O 2 plasma treatment, surface characterizations were examined by scanning electron microscopy, atomic force microscopy, and contact angle. MTT assay was used to determine cell proliferation. To investigate the early new bone formation, rabbits were sacrificed at 2 weeks for histological analyses. As the O 2 plasma etching time is increased, roughness and hydrophilicity of the PCL scaffold surface increased. The cell proliferation and differentiation on plasma-etched samples was significantly increased than on untreated samples. At 2 weeks, early new bone formation in O 2 plasma-etched PCL scaffolds was the higher than that of untreated scaffolds. The O 2 plasma-etched PCL scaffolds showed increased preosteoblast differentiation as well as increased new bone formation.

  11. Post Processing and Biological Evaluation of the Titanium Scaffolds for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Bartłomiej Wysocki

    2016-03-01

    Full Text Available Nowadays, post-surgical or post-accidental bone loss can be substituted by custom-made scaffolds fabricated by additive manufacturing (AM methods from metallic powders. However, the partially melted powder particles must be removed in a post-process chemical treatment. The aim of this study was to investigate the effect of the chemical polishing with various acid baths on novel scaffolds’ morphology, porosity and mechanical properties. In the first stage, Magics software (Materialise NV, Leuven, Belgium was used to design a porous scaffolds with pore size equal to (A 200 µm, (B 500 µm and (C 200 + 500 µm, and diamond cell structure. The scaffolds were fabricated from commercially pure titanium powder (CP Ti using a SLM50 3D printing machine (Realizer GmbH, Borchen, Germany. The selective laser melting (SLM process was optimized and the laser beam energy density in range of 91–151 J/mm3 was applied to receive 3D structures with fully dense struts. To remove not fully melted titanium particles the scaffolds were chemically polished using various HF and HF-HNO3 acid solutions. Based on scaffolds mass loss and scanning electron (SEM observations, baths which provided most uniform surface cleaning were proposed for each porosity. The pore and strut size after chemical treatments was calculated based on the micro-computed tomography (µ-CT and SEM images. The mechanical tests showed that the treated scaffolds had Young’s modulus close to that of compact bone. Additionally, the effect of pore size of chemically polished scaffolds on cell retention, proliferation and differentiation was studied using human mesenchymal stem cells. Small pores yielded higher cell retention within the scaffolds, which then affected their growth. This shows that in vitro cell performance can be controlled to certain extent by varying pore sizes.

  12. Pilates, Mindfulness and Somatic Education.

    Science.gov (United States)

    Caldwell, Karen; Adams, Marianne; Quin, Rebecca; Harrison, Mandy; Greeson, Jeffrey

    2013-12-01

    The Pilates Method is a form of somatic education with the potential to cultivate mindfulness - a mental quality associated with overall well-being. However, controlled studies are needed to determine whether changes in mindfulness are specific to the Pilates Method or also result from other forms of exercise. This quasi-experimental study compared Pilates Method mat classes and recreational exercise classes on measures of mindfulness and well-being at the beginning, middle and end of a 15 week semester. Total mindfulness scores increased overall for the Pilates Method group but not for the exercise control group, and these increases were directly related to end of semester ratings of self-regulatory self-efficacy, perceived stress and mood. Findings suggest that the Pilates Method specifically enhances mindfulness, and these increases are associated with other measures of wellness. The changes in mindfulness identified in this study support the role of the Pilates Method in the mental well-being of its practitioners and its potential to support dancers' overall well-being.

  13. A closer look at the relationship between the default network, mind wandering, negative mood, and depression.

    Science.gov (United States)

    Konjedi, Shaghayegh; Maleeh, Reza

    2017-08-01

    By a systematic analysis of the current literature on the neural correlates of mind wandering, that is, the default network (DN), and by shedding light on some determinative factors and conditions which affect the relationship between mind wandering and negative mood, we show that (1) mind wandering per se does not necessarily have a positive correlation with negative mood and, on the higher levels, depression. We propose that negative mood as a consequence of mind wandering generally depends on two determinative conditions, that is, whether mind wandering is with or without meta-awareness and whether mind wandering occurs during high or low vigilance states; (2) increased activity of the DN is not necessarily followed by an increase in unhappiness and depression. We argue that while in some kinds of meditation practices we witness an increase in the structure and in the activity of the DN, no increase in unhappiness and depression is observed.

  14. Teenaged Internet Tutors' Use of Scaffolding with Older Learners

    Science.gov (United States)

    Tambaum, Tiina

    2017-01-01

    This study analyses how teenaged instructors paired with older learners make use of scaffolding. Video data were categorised according to 15 types of direct scaffolding tactics, indirect scaffolding, and unused scaffolding opportunities. The results show that a teenager who is unprepared for the role of an instructor of Internet skills for older…

  15. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Beke, S., E-mail: szabolcs.beke@iit.it [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Kőrösi, L. [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632, Pécs (Hungary); Scarpellini, A. [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Anjum, F.; Brandi, F. [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy)

    2013-05-01

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications.

  16. Scaffold translation: barriers between concept and clinic.

    Science.gov (United States)

    Hollister, Scott J; Murphy, William L

    2011-12-01

    Translation of scaffold-based bone tissue engineering (BTE) therapies to clinical use remains, bluntly, a failure. This dearth of translated tissue engineering therapies (including scaffolds) remains despite 25 years of research, research funding totaling hundreds of millions of dollars, over 12,000 papers on BTE and over 2000 papers on BTE scaffolds alone in the past 10 years (PubMed search). Enabling scaffold translation requires first an understanding of the challenges, and second, addressing the complete range of these challenges. There are the obvious technical challenges of designing, manufacturing, and functionalizing scaffolds to fill the Form, Fixation, Function, and Formation needs of bone defect repair. However, these technical solutions should be targeted to specific clinical indications (e.g., mandibular defects, spine fusion, long bone defects, etc.). Further, technical solutions should also address business challenges, including the need to obtain regulatory approval, meet specific market needs, and obtain private investment to develop products, again for specific clinical indications. Finally, these business and technical challenges present a much different model than the typical research paradigm, presenting the field with philosophical challenges in terms of publishing and funding priorities that should be addressed as well. In this article, we review in detail the technical, business, and philosophical barriers of translating scaffolds from Concept to Clinic. We argue that envisioning and engineering scaffolds as modular systems with a sliding scale of complexity offers the best path to addressing these translational challenges. © Mary Ann Liebert, Inc.

  17. Inverse Opal Scaffolds and Their Biomedical Applications.

    Science.gov (United States)

    Zhang, Yu Shrike; Zhu, Chunlei; Xia, Younan

    2017-09-01

    Three-dimensional porous scaffolds play a pivotal role in tissue engineering and regenerative medicine by functioning as biomimetic substrates to manipulate cellular behaviors. While many techniques have been developed to fabricate porous scaffolds, most of them rely on stochastic processes that typically result in scaffolds with pores uncontrolled in terms of size, structure, and interconnectivity, greatly limiting their use in tissue regeneration. Inverse opal scaffolds, in contrast, possess uniform pores inheriting from the template comprised of a closely packed lattice of monodispersed microspheres. The key parameters of such scaffolds, including architecture, pore structure, porosity, and interconnectivity, can all be made uniform across the same sample and among different samples. In conjunction with a tight control over pore sizes, inverse opal scaffolds have found widespread use in biomedical applications. In this review, we provide a detailed discussion on this new class of advanced materials. After a brief introduction to their history and fabrication, we highlight the unique advantages of inverse opal scaffolds over their non-uniform counterparts. We then showcase their broad applications in tissue engineering and regenerative medicine, followed by a summary and perspective on future directions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Multilayer scaffolds in orthopaedic tissue engineering.

    Science.gov (United States)

    Atesok, Kivanc; Doral, M Nedim; Karlsson, Jon; Egol, Kenneth A; Jazrawi, Laith M; Coelho, Paulo G; Martinez, Amaury; Matsumoto, Tomoyuki; Owens, Brett D; Ochi, Mitsuo; Hurwitz, Shepard R; Atala, Anthony; Fu, Freddie H; Lu, Helen H; Rodeo, Scott A

    2016-07-01

    The purpose of this study was to summarize the recent developments in the field of tissue engineering as they relate to multilayer scaffold designs in musculoskeletal regeneration. Clinical and basic research studies that highlight the current knowledge and potential future applications of the multilayer scaffolds in orthopaedic tissue engineering were evaluated and the best evidence collected. Studies were divided into three main categories based on tissue types and interfaces for which multilayer scaffolds were used to regenerate: bone, osteochondral junction and tendon-to-bone interfaces. In vitro and in vivo studies indicate that the use of stratified scaffolds composed of multiple layers with distinct compositions for regeneration of distinct tissue types within the same scaffold and anatomic location is feasible. This emerging tissue engineering approach has potential applications in regeneration of bone defects, osteochondral lesions and tendon-to-bone interfaces with successful basic research findings that encourage clinical applications. Present data supporting the advantages of the use of multilayer scaffolds as an emerging strategy in musculoskeletal tissue engineering are promising, however, still limited. Positive impacts of the use of next generation scaffolds in orthopaedic tissue engineering can be expected in terms of decreasing the invasiveness of current grafting techniques used for reconstruction of bone and osteochondral defects, and tendon-to-bone interfaces in near future.

  19. Higher Education Leadership Graduate Program Development

    Science.gov (United States)

    Freeman, Sydney, Jr.; Chambers, Crystal Renée; Newton, Rochelle

    2016-01-01

    Graduate programs in higher education administration and leadership have sought to equip students with the knowledge, skills, and competencies for higher education leadership; that is, to prepare globally minded leaders who can navigate the internal and external demands of, and for, higher education. With the use of the Lattuca and Stark model of…

  20. Contribution of Mindfulness and Emotional Intelligence to Burnout among Counseling Interns

    Science.gov (United States)

    Testa, Daniel; Sangganjanavanich, Varunee Faii

    2016-01-01

    The authors examined the contribution of mindfulness and emotional intelligence to burnout among counseling interns (N = 380). Results indicated that higher scores on mindfulness and emotional intelligence were related to lower burnout scores. Counselor educators and supervisors should be proactive in helping students to cultivate wellness…

  1. Scaffolding With and Through Videos

    DEFF Research Database (Denmark)

    Otrel-Cass, Kathrin; Khoo, Elaine; Cowie, Bronwen

    2012-01-01

    In New Zealand and internationally claims are being made about the potential for information and communication technologies (ICTs) to transform teaching and learning. However, the theoretical underpinnings explaining the complex interplay between the content, pedagogy and technology a teacher needs...... to scaffold learning. It showcases the intricate interplay between teachers’ knowledge about content, digital video technology, and students’ learning needs based on a qualitative study of two science teachers and their students in a New Zealand primary school....... to consider must be expanded. This article explicates theoretical and practical ideas related to teachers’ application of their ICT technology, pedagogy, and content knowledge (TPACK) in science. The article unpacks the social and technological dimensions of teachers’ use of TPACK when they use digital videos...

  2. Semiotic Scaffolding in Living Systems

    DEFF Research Database (Denmark)

    Hoffmeyer, Jesper

    2008-01-01

    The apparently purposeful nature of living systems is obtained through a sophisticated network of semiotic controls whereby biochemical, physiological and behavioral processes become tuned to the needs of the system. The operation of these semiotic controls takes place and is enabled across...... a diversity of levels. Such semiotic controls may be distinguished from ordinary deterministic control mechanisms through an inbuilt anticipatory capacity based on a distinct kind of causation that I call here "semiotic causation" to denote the bringing about of changes under the guidance of interpretation...... in a local .context. Anticipation through the skilled interpretation of indicators of temporal relations in the context of a particular survival project (or life strategy) guides organismic behavior towards local ends. This network of semiotic controls establishes an enormously complex semiotic scaffolding...

  3. Computational Exploration of Molecular Scaffolds in Medicinal Chemistry.

    Science.gov (United States)

    Hu, Ye; Stumpfe, Dagmar; Bajorath, Jürgen

    2016-05-12

    The scaffold concept is widely applied in medicinal chemistry. Scaffolds are mostly used to represent core structures of bioactive compounds. Although the scaffold concept has limitations and is often viewed differently from a chemical and computational perspective, it has provided a basis for systematic investigations of molecular cores and building blocks, going far beyond the consideration of individual compound series. Over the past 2 decades, alternative scaffold definitions and organization schemes have been introduced and scaffolds have been studied in a variety of ways and increasingly on a large scale. Major applications of the scaffold concept include the generation of molecular hierarchies, structural classification, association of scaffolds with biological activities, and activity prediction. This contribution discusses computational approaches for scaffold generation and analysis, with emphasis on recent developments impacting medicinal chemistry. A variety of scaffold-based studies are discussed, and a perspective on scaffold methods is provided.

  4. Toward physics of the mind: Concepts, emotions, consciousness, and symbols

    Science.gov (United States)

    Perlovsky, Leonid I.

    2006-03-01

    Mathematical approaches to modeling the mind since the 1950s are reviewed, including artificial intelligence, pattern recognition, and neural networks. I analyze difficulties faced by these algorithms and neural networks and relate them to the fundamental inconsistency of logic discovered by Gödel. Mathematical discussions are related to those in neurobiology, psychology, cognitive science, and philosophy. Higher cognitive functions are reviewed including concepts, emotions, instincts, understanding, imagination, intuition, consciousness. Then, I describe a mathematical formulation, unifying the mind mechanisms in a psychologically and neuro-biologically plausible system. A mechanism of the knowledge instinct drives our understanding of the world and serves as a foundation for higher cognitive functions. This mechanism relates aesthetic emotions and perception of beauty to “everyday” functioning of the mind. The article reviews mechanisms of human symbolic ability. I touch on future directions: joint evolution of the mind, language, consciousness, and cultures; mechanisms of differentiation and synthesis; a manifold of aesthetic emotions in music and differentiated instinct for knowledge. I concentrate on elucidating the first principles; review aspects of the theory that have been proven in laboratory research, relationships between the mind and brain; discuss unsolved problems, and outline a number of theoretical predictions, which will have to be tested in future mathematical simulations and neuro-biological research.

  5. Chitosan scaffolds induce human dental pulp stem cells to neural differentiation: potential roles for spinal cord injury therapy.

    Science.gov (United States)

    Zhang, Jinlong; Lu, Xiaohui; Feng, Guijuan; Gu, Zhifeng; Sun, Yuyu; Bao, Guofeng; Xu, Guanhua; Lu, Yuanzhou; Chen, Jiajia; Xu, Lingfeng; Feng, Xingmei; Cui, Zhiming

    2016-10-01

    Cell-based transplantation strategies hold great potential for spinal cord injury (SCI) repair. Chitosan scaffolds have therapeutic benefits for spinal cord regeneration. Human dental pulp stem cells (DPSCs) are abundant available stem cells with low immunological incompatibility and can be considered for cell replacement therapy. The purpose of this study is to investigate the role of chitosan scaffolds in the neural differentiation of DPSCs in vitro and to assess the supportive effects of chitosan scaffolds in an animal model of SCI. DPSCs were incubated with chitosan scaffolds. Cell viability and the secretion of neurotrophic factors were analyzed. DPSCs incubated with chitosan scaffolds were treated with neural differentiation medium for 14 days and then neural genes and protein markers were analyzed by Western blot and reverse transcription plus the polymerase chain reaction. Our study revealed a higher cell viability and neural differentiation in the DPSC/chitosan-scaffold group. Compared with the control group, the levels of BDNF, GDNF, b-NGF, and NT-3 were significantly increased in the DPSC/chitosan-scaffold group. The Wnt/β-catenin signaling pathway played a key role in the neural differentiation of DPSCs combined with chitosan scaffolds. Transplantation of DPSCs together with chitosan scaffolds into an SCI rat model resulted in the marked recovery of hind limb locomotor functions. Thus, chitosan scaffolds were non-cytotoxic and provided a conducive and favorable microenvironment for the survival and neural differentiation of DPSCs. Transplantation of DPSCs might therefore be a suitable candidate for treating SCI and other neuronal degenerative diseases.

  6. Designing, Prototyping and Evaluating Digital Mindfulness Applications: A Case Study of Mindful Breathing for Stress Reduction.

    Science.gov (United States)

    Zhu, Bin; Hedman, Anders; Feng, Shuo; Li, Haibo; Osika, Walter

    2017-06-14

    silent and sonified HU. The mean value of HR using silent HU was significantly lower than resting baseline and sonified HU. The mean value of root mean square of differences (RMSSD) using silent HU was significantly higher than resting baseline. We found that the differences between our objective and subjective assessments were intriguing and prompted us to investigate them further. Our evaluation of HU indicated that HU could facilitate relaxed breathing and stress reduction. There was a difference in outcome between the physiological measures of stress and the subjective reports of stress, as well as a large intervariability among study participants. Our conclusion is that the use of stress reduction tools should be customized and that the design work of mindfulness technology for stress reduction is a complex process, which requires cooperation of designers, HCI (Human-Computer Interaction) experts and clinicians. ©Bin Zhu, Anders Hedman, Shuo Feng, Haibo Li, Walter Osika. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 14.06.2017.

  7. "Mind the trap": mindfulness practice reduces cognitive rigidity.

    Directory of Open Access Journals (Sweden)

    Jonathan Greenberg

    Full Text Available Two experiments examined the relation between mindfulness practice and cognitive rigidity by using a variation of the Einstellung water jar task. Participants were required to use three hypothetical jars to obtain a specific amount of water. Initial problems were solvable by the same complex formula, but in later problems ("critical" or "trap" problems solving was possible by an additional much simpler formula. A rigidity score was compiled through perseverance of the complex formula. In Experiment 1, experienced mindfulness meditators received significantly lower rigidity scores than non-meditators who had registered for their first meditation retreat. Similar results were obtained in randomized controlled Experiment 2 comparing non-meditators who underwent an eight meeting mindfulness program with a waiting list group. The authors conclude that mindfulness meditation reduces cognitive rigidity via the tendency to be "blinded" by experience. Results are discussed in light of the benefits of mindfulness practice regarding a reduced tendency to overlook novel and adaptive ways of responding due to past experience, both in and out of the clinical setting.

  8. Whole mind and shared mind in clinical decision-making.

    Science.gov (United States)

    Epstein, Ronald Mark

    2013-02-01

    To review the theory, research evidence and ethical implications regarding "whole mind" and "shared mind" in clinical practice in the context of chronic and serious illnesses. Selective critical review of the intersection of classical and naturalistic decision-making theories, cognitive neuroscience, communication research and ethics as they apply to decision-making and autonomy. Decision-making involves analytic thinking as well as affect and intuition ("whole mind") and sharing cognitive and affective schemas of two or more individuals ("shared mind"). Social relationships can help processing of complex information that otherwise would overwhelm individuals' cognitive capacities. Medical decision-making research, teaching and practice should consider both analytic and non-analytic cognitive processes. Further, research should consider that decisions emerge not only from the individual perspectives of patients, their families and clinicians, but also the perspectives that emerge from the interactions among them. Social interactions have the potential to enhance individual autonomy, as well as to promote relational autonomy based on shared frames of reference. Shared mind has the potential to result in wiser decisions, greater autonomy and self-determination; yet, clinicians and patients should be vigilant for the potential of hierarchical relationships to foster coercion or silencing of the patient's voice. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Minding the Body

    Directory of Open Access Journals (Sweden)

    Anastasia Ioanna Kayiatos

    2015-05-01

    Full Text Available In the Fall of 2013 we team-taught a disability studies course for a small group of first-year students. The course, Minding the Body, integrated scholarship from disability studies, feminist/queer studies, psychology, and Russian Studies. Originally envisioned and taught independently in the Fall of 2012 by Joan Ostrove and focused entirely on the U.S., Anastasia Kayiatos's arrival in the Department of German and Russian Studies at Macalester College afforded us an opportunity for collaboration and co-instruction that we found invigorating, compelling, and transformative. Grounded from the outset in disability studies, the course asked students to interrogate such questions as: What is a "normal" body? A "beautiful" body? Why do we feel the way we do about our bodies? How are bodies objectified, exploited, and regulated? How and why do we discriminate against people with non-normative bodies? How do people represent the experience of having a disabled body? How can we think critically about the various ways in which people change, regulate, and enhance their bodies? How do sexism, racism, classism, colonialism, homophobia, transphobia and other forms of oppression influence how different bodies are viewed, treated, educated, and experienced? The integration of Russian Studies importantly allowed us to ask how these questions and ideas change when we travel across time and geographical space. In our paper we will reflect on our experience of co-authoring the syllabus (we will include both the solo-taught and co-taught versions of the syllabus in an appendix; outline some of our techniques for team-teaching; and analyze an exemplary assignment and class meeting. We will conclude with a final word about the unique forms of teaching and learning that happened in our class as a consequence of its collaborative and interdisciplinary approach, which opened up new perspectives in disability studies not only for our students but also for us.

  10. Strontium eluting graphene hybrid nanoparticles augment osteogenesis in a 3D tissue scaffold

    Science.gov (United States)

    Kumar, Sachin; Chatterjee, Kaushik

    2015-01-01

    The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium particles. Thermal gravimetric analysis further confirmed the composition of the hybrid particles as 22 wt% of strontium. Macroporous tissue scaffolds were prepared by incorporating RGO_Sr particles in poly(ε-caprolactone) (PCL). The PCL/RGO_Sr scaffolds were found to elute strontium ions in aqueous medium. Osteoblast proliferation and differentiation was significantly higher in the PCL scaffolds containing the RGO_Sr particles in contrast to neat PCL and PCL/RGO scaffolds. The increased biological activity can be attributed to the release of strontium ions from the hybrid nanoparticles. This study demonstrates that composites prepared using hybrid nanoparticles that elute strontium ions can be used to prepare multifunctional scaffolds with good mechanical and osteoinductive properties. These findings have important implications for designing the next generation of biomaterials for use in tissue regeneration.The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium

  11. Analog series-based scaffolds: computational design and exploration of a new type of molecular scaffolds for medicinal chemistry

    Science.gov (United States)

    Dimova, Dilyana; Stumpfe, Dagmar; Hu, Ye; Bajorath, Jürgen

    2016-01-01

    Aim: Computational design of and systematic search for a new type of molecular scaffolds termed analog series-based scaffolds. Materials & methods: From currently available bioactive compounds, analog series were systematically extracted, key compounds identified and new scaffolds isolated from them. Results: Using our computational approach, more than 12,000 scaffolds were extracted from bioactive compounds. Conclusion: A new scaffold definition is introduced and a computational methodology developed to systematically identify such scaffolds, yielding a large freely available scaffold knowledge base. PMID:28116132

  12. Effect of the biodegradation rate controlled by pore structures in magnesium phosphate ceramic scaffolds on bone tissue regeneration in vivo.

    Science.gov (United States)

    Kim, Ju-Ang; Lim, Jiwon; Naren, Raja; Yun, Hui-Suk; Park, Eui Kyun

    2016-10-15

    Similar to calcium phosphates, magnesium phosphate (MgP) ceramics have been shown to be biocompatible and support favorable conditions for bone cells. Micropores below 25μm (MgP25), between 25 and 53μm (MgP53), or no micropores (MgP0) were introduced into MgP scaffolds using different sizes of an NaCl template. The porosities of MgP25 and MgP53 were found to be higher than that of MgP0 because of their micro-sized pores. Both in vitro and in vivo analysis showed that MgP scaffolds with high porosity promoted rapid biodegradation. Implantation of the MgP0, MgP25, and MgP53 scaffolds into rabbit calvarial defects (with 4- and 6-mm diameters) was assessed at two times points (4 and 8weeks), followed by analysis of bone regeneration. The micro-CT and histologic analyses of the 4-mm defect showed that the MgP25 and MgP53 scaffolds were degraded completely at 4weeks with simultaneous bone and marrow-like structure regeneration. For the 6-mm defect, a similar pattern of regeneration was observed. These results indicate that the rate of degradation is associated with bone regeneration. The MgP25 and MgP53 scaffold-implanted bone showed a better lamellar structure and enhanced calcification compared to the MgP0 scaffold because of their porosity and degradation rate. Tartrate-resistant acid phosphatase (TRAP) staining indicated that the newly formed bone was undergoing maturation and remodeling. Overall, these data suggest that the pore architecture of MgP ceramic scaffolds greatly influence bone formation and remodeling activities and thus should be considered in the design of new scaffolds for long-term bone tissue regeneration. The pore structural conditions of scaffold, including porosity, pore size, pore morphology, and pore interconnectivity affect cell ingrowth, mechanical properties and biodegradabilities, which are key components of scaffold in bone tissue regeneration. In this study, we designed hierarchical pore structure of the magnesium phosphate (Mg

  13. Comprehensive assessment of electrospun scaffolds hemocompatibility

    Czech Academy of Sciences Publication Activity Database

    Horáková, J.; Mikeš, P.; Šaman, A.; Švarcová, T.; Jenčová, V.; Suchý, Tomáš; Heczková, B.; Jakubková, Š.; Jiroušová, J.; Procházková, R.

    2018-01-01

    Roč. 82, JAN 1 (2018), s. 330-335 ISSN 0928-4931 Institutional support: RVO:67985891 Keywords : fibrous scaffolds * blood compatibility * polycaprolactone * copolymer of polylactide and polycaprolactone * collagen Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  14. Biomimetic nanoclay scaffolds for bone tissue engineering

    Science.gov (United States)

    Ambre, Avinash Harishchandra

    Tissue engineering offers a significant potential alternative to conventional methods for rectifying tissue defects by evoking natural regeneration process via interactions between cells and 3D porous scaffolds. Imparting adequate mechanical properties to biodegradable scaffolds for bone tissue engineering is an important challenge and extends from molecular to macroscale. This work focuses on the use of sodium montmorillonite (Na-MMT) to design polymer composite scaffolds having enhanced mechanical properties along with multiple interdependent properties. Materials design beginning at the molecular level was used in which Na-MMT clay was modified with three different unnatural amino acids and further characterized using Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD). Based on improved bicompatibility with human osteoblasts (bone cells) and intermediate increase in d-spacing of MMT clay (shown by XRD), 5-aminovaleric acid modified clay was further used to prepare biopolymer (chitosan-polygalacturonic acid complex) scaffolds. Osteoblast proliferation in biopolymer scaffolds containing 5-aminovaleric acid modified clay was similar to biopolymer scaffolds containing hydroxyapatite (HAP). A novel process based on biomineralization in bone was designed to prepare 5-aminovaleric acid modified clay capable of imparting multiple properties to the scaffolds. Bone-like apatite was mineralized in modified clay and a novel nanoclay-HAP hybrid (in situ HAPclay) was obtained. FTIR spectroscopy indicated a molecular level organic-inorganic association between the intercalated 5-aminovaleric acid and mineralized HAP. Osteoblasts formed clusters on biopolymer composite films prepared with different weight percent compositions of in situ HAPclay. Human MSCs formed mineralized nodules on composite films and mineralized extracellular matrix (ECM) in composite scaffolds without the use of osteogenic supplements. Polycaprolactone (PCL), a synthetic polymer, was

  15. Brug af mindfulness til facilitering

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Krohn, Simon

    2011-01-01

    Gennem de senere år er mindfulness gået fra udelukkende at være en eksistentiel praksis til også at være en behandlingsform og senest til også at blive brugt som et praktisk redskab i erhvervslivet. Denne artikel viser, at mindfulness også kan anvendes i forbindelse med facilitering. Facilitering...... er et værktøj, som bruges i arbejdslivet fx til møder og konferencer, hvor en gruppe mennesker er samlet for at lære eller udrette noget sammen. Det nye ved at kombinere mindfulness med facilitering er, at fokus hermed ændres fra individet, som er centrum for den eksistentielle fordybelse eller det...... terapeutiske forløb, til gruppen, som er udgangspunktet i facilitering. Artiklen viser, hvordan mindfulness konkret kan bruges på gruppeniveau og diskuterer samtidig hvilke problemer, der kan være forbundet hermed. Baseret på vores egne erfaringer, diskuterer vi, hvordan mindfulness kan påvirke en gruppes...

  16. Effects of cell-attachment and extracellular matrix on bone formation in vivo in collagen-hydroxyapatite scaffolds.

    Science.gov (United States)

    Villa, Max M; Wang, Liping; Rowe, David W; Wei, Mei

    2014-01-01

    Cell-based tissue engineering can be used to replace missing or damaged bone, but the optimal methods for delivering therapeutic cells to a bony defect have not yet been established. Using transgenic reporter cells as a donor source, two different collagen-hydroxyapatite (HA) scaffolds, and a critical-size calvarial defect model, we investigated the effect of a cell-attachment period prior to implantation, with or without an extracellular matrix-based seeding suspension, on cell engraftment and osteogenesis. When quantitatively compared, the in-house scaffold implanted immediately had a higher mean radiopacity than in-house scaffolds incubated overnight. Both scaffold types implanted immediately had significantly higher area fractions of donor cells, while the in-house collagen-HA scaffolds implanted immediately had higher area fractions of the mineralization label compared with groups incubated overnight. When the cell loading was compared in vitro for each delivery method using the in-house scaffold, immediate loading led to higher numbers of delivered cells. Immediate loading may be preferable in order to ensure robust bone formation in vivo. The use of a secondary ECM carrier improved the distribution of donor cells only when a pre-attachment period was applied. These results have improved our understanding of cell delivery to bony defects in the context of in vivo outcomes.

  17. Calcium phosphate cement scaffolds with PLGA fibers.

    Science.gov (United States)

    Vasconcellos, Letícia Araújo; dos Santos, Luís Alberto

    2013-04-01

    The use of calcium phosphate-based biomaterials has revolutionized current orthopedics and dentistry in repairing damaged parts of the skeletal system. Among those biomaterials, the cement made of hydraulic grip calcium phosphate has attracted great interest due to its biocompatibility and hardening "in situ". However, these cements have low mechanical strength compared with the bones of the human body. In the present work, we have studied the attainment of calcium phosphate cement powders and their addition to poly (co-glycolide) (PLGA) fibers to increase mechanical properties of those cements. We have used a new method that obtains fibers by dripping different reagents. PLGA fibers were frozen after lyophilized. With this new method, which was patented, it was possible to obtain fibers and reinforcing matrix which furthered the increase of mechanical properties, thus allowing the attainment of more resistant materials. The obtained materials were used in the construction of composites and scaffolds for tissue growth, keeping a higher mechanical integrity. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Super dielectric capacitor using scaffold dielectric

    OpenAIRE

    Phillips, Jonathan

    2018-01-01

    Patent A capacitor having first and second electrodes and a scaffold dielectric. The scaffold dielectric comprises an insulating material with a plurality of longitudinal channels extending across the dielectric and filled with a liquid comprising cations and anions. The plurality of longitudinal channels are substantially parallel and the liquid within the longitudinal channels generally has an ionic strength of at least 0.1. Capacitance results from the migrations of...

  19. Hypnosis and Mindfulness: The Twain Finally Meet.

    Science.gov (United States)

    Otani, Akira

    2016-04-01

    Mindfulness meditation (or simply mindfulness) is an ancient method of attention training. Arguably, developed originally by the Buddha, it has been practiced by Buddhists over 2,500 years as part of their spiritual training. The popularity in mindfulness has soared recently following its adaptation as Mindfulness-Based Stress Management by Jon Kabat-Zinn (1995). Mindfulness is often compared to hypnosis but not all assertions are accurate. This article, as a primer, delineates similarities and dissimilarities between mindfulness and hypnosis in terms of 12 specific facets, including putative neuroscientific findings. It also provides a case example that illustrates clinical integration of the two methods.

  20. Otak, Bahasa dan Pikiran dalam Mind Map

    OpenAIRE

    Siti Shalihah

    2014-01-01

    Language and mind are firmly related to each other. The mind can not be separated from language, since language is expressions of minds. Without language, one can not be able to convey things in his/her minds and they are never be able to be understood by the others. Thus, language is the way to grasp one's thought.  This article deals with the relationship between Mind Map and the structure of brain, how it works, and what to do with language and thinking. From concept of mind map ...

  1. Scaling of Advanced Theory-of-Mind Tasks

    Science.gov (United States)

    Osterhaus, Christopher; Koerber, Susanne; Sodian, Beate

    2016-01-01

    Advanced theory-of-mind (AToM) development was investigated in three separate studies involving 82, 466, and 402 elementary school children (8-, 9-, and 10-year-olds). Rasch and factor analyses assessed whether common conceptual development underlies higher-order false-belief understanding, social understanding, emotion recognition, and…

  2. Is mind-mindedness trait-like or a quality of close relationships? Evidence from descriptions of significant others, famous people, and works of art.

    Science.gov (United States)

    Meins, Elizabeth; Fernyhough, Charles; Harris-Waller, Jayne

    2014-03-01

    The four studies reported here sought to explore the nature of the construct of mind-mindedness. In Study 1, involving 37 mothers of 5- to 8-year-old children, mothers' verbal mind-minded descriptions of their children were positively correlated with their mind-minded descriptions of their current romantic partner. Participants in Studies 2 (N=114), 3 (N=173), and 4 (N=153) were young adults who provided written descriptions of: a close friend and their current romantic partner (Study 2); two specified famous people, two works of art, and a close friend (Study 3); a specified famous person, a famous person of the participant's choice, and a close friend (Study 4). Study 2 obtained paper-and-pen written descriptions, whereas participants completed descriptions in electronic format in Studies 3 and 4. Mind-minded descriptions of friends and partners were positively correlated, but there was no relation between mind-minded descriptions of a friend and the tendency to describe famous people or works of art in mind-minded terms. Levels of mind-mindedness were higher in descriptions of friends compared with descriptions of famous people or works of art. Administration format was unrelated to individuals' mind-mindedness scores. The results suggest that mind-mindedness is a facet of personal relationships rather than a trait-like quality. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. The pro-angiogenic properties of multi-functional bioactive glass composite scaffolds

    KAUST Repository

    Gerhardt, Lutz Christian; Widdows, Kate L.; Erol, Melek M.; Burch, Charles W.; Sanz-Herrera, José A.; Ochoa, Ignacio; Stä mpfli, Rolf; Roqan, Iman S.; Gabe, Simon M.; Ansari, Tahera I.; Boccaccini, Aldo R.

    2011-01-01

    The angiogenic properties of micron-sized (m-BG) and nano-sized (n-BG) bioactive glass (BG) filled poly(D,L lactide) (PDLLA) composites were investigated. On the basis of cell culture work investigating the secretion of vascular endothelial growth factor (VEGF) by human fibroblasts in contact with composite films (0, 5, 10, 20 wt %), porous 3D composite scaffolds, optimised with respect to the BG filler content capable of inducing angiogenic response, were produced. The in vivo vascularisation of the scaffolds was studied in a rat animal model and quantified using stereological analyses. The prepared scaffolds had high porosities (81-93%), permeability (k = 5.4-8.6 × 10-9 m2) and compressive strength values (0.4-1.6 MPa) all in the range of trabecular bone. On composite films containing 20 wt % m-BG or n-BG, human fibroblasts produced 5 times higher VEGF than on pure PDLLA films. After 8 weeks of implantation, m-BG and n-BG containing scaffolds were well-infiltrated with newly formed tissue and demonstrated higher vascularisation and percentage blood vessel to tissue (11.6-15.1%) than PDLLA scaffolds (8.5%). This work thus shows potential for the regeneration of hard-soft tissue defects and increased bone formation arising from enhanced vascularisation of the construct. © 2011 Elsevier Ltd.

  4. The pro-angiogenic properties of multi-functional bioactive glass composite scaffolds

    KAUST Repository

    Gerhardt, Lutz Christian

    2011-06-01

    The angiogenic properties of micron-sized (m-BG) and nano-sized (n-BG) bioactive glass (BG) filled poly(D,L lactide) (PDLLA) composites were investigated. On the basis of cell culture work investigating the secretion of vascular endothelial growth factor (VEGF) by human fibroblasts in contact with composite films (0, 5, 10, 20 wt %), porous 3D composite scaffolds, optimised with respect to the BG filler content capable of inducing angiogenic response, were produced. The in vivo vascularisation of the scaffolds was studied in a rat animal model and quantified using stereological analyses. The prepared scaffolds had high porosities (81-93%), permeability (k = 5.4-8.6 × 10-9 m2) and compressive strength values (0.4-1.6 MPa) all in the range of trabecular bone. On composite films containing 20 wt % m-BG or n-BG, human fibroblasts produced 5 times higher VEGF than on pure PDLLA films. After 8 weeks of implantation, m-BG and n-BG containing scaffolds were well-infiltrated with newly formed tissue and demonstrated higher vascularisation and percentage blood vessel to tissue (11.6-15.1%) than PDLLA scaffolds (8.5%). This work thus shows potential for the regeneration of hard-soft tissue defects and increased bone formation arising from enhanced vascularisation of the construct. © 2011 Elsevier Ltd.

  5. A review: fabrication of porous polyurethane scaffolds.

    Science.gov (United States)

    Janik, H; Marzec, M

    2015-03-01

    The aim of tissue engineering is the fabrication of three-dimensional scaffolds that can be used for the reconstruction and regeneration of damaged or deformed tissues and organs. A wide variety of techniques have been developed to create either fibrous or porous scaffolds from polymers, metals, composite materials and ceramics. However, the most promising materials are biodegradable polymers due to their comprehensive mechanical properties, ability to control the rate of degradation and similarities to natural tissue structures. Polyurethanes (PUs) are attractive candidates for scaffold fabrication, since they are biocompatible, and have excellent mechanical properties and mechanical flexibility. PU can be applied to various methods of porous scaffold fabrication, among which are solvent casting/particulate leaching, thermally induced phase separation, gas foaming, emulsion freeze-drying and melt moulding. Scaffold properties obtained by these techniques, including pore size, interconnectivity and total porosity, all depend on the thermal processing parameters, and the porogen agent and solvents used. In this review, various polyurethane systems for scaffolds are discussed, as well as methods of fabrication, including the latest developments, and their advantages and disadvantages. Copyright © 2014. Published by Elsevier B.V.

  6. Scaffolds for peripheral nerve repair and reconstruction.

    Science.gov (United States)

    Yi, Sheng; Xu, Lai; Gu, Xiaosong

    2018-06-02

    Trauma-associated peripheral nerve defect is a widespread clinical problem. Autologous nerve grafting, the current gold standard technique for the treatment of peripheral nerve injury, has many internal disadvantages. Emerging studies showed that tissue engineered nerve graft is an effective substitute to autologous nerves. Tissue engineered nerve graft is generally composed of neural scaffolds and incorporating cells and molecules. A variety of biomaterials have been used to construct neural scaffolds, the main component of tissue engineered nerve graft. Synthetic polymers (e.g. silicone, polyglycolic acid, and poly(lactic-co-glycolic acid)) and natural materials (e.g. chitosan, silk fibroin, and extracellular matrix components) are commonly used along or together to build neural scaffolds. Many other materials, including the extracellular matrix, glass fabrics, ceramics, and metallic materials, have also been used to construct neural scaffolds. These biomaterials are fabricated to create specific structures and surface features. Seeding supporting cells and/or incorporating neurotrophic factors to neural scaffolds further improve restoration effects. Preliminary studies demonstrate that clinical applications of these neural scaffolds achieve satisfactory functional recovery. Therefore, tissue engineered nerve graft provides a good alternative to autologous nerve graft and represents a promising frontier in neural tissue engineering. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Strategies for osteochondral repair: Focus on scaffolds

    Directory of Open Access Journals (Sweden)

    Seog-Jin Seo

    2014-07-01

    Full Text Available Interest in osteochondral repair has been increasing with the growing number of sports-related injuries, accident traumas, and congenital diseases and disorders. Although therapeutic interventions are entering an advanced stage, current surgical procedures are still in their infancy. Unlike other tissues, the osteochondral zone shows a high level of gradient and interfacial tissue organization between bone and cartilage, and thus has unique characteristics related to the ability to resist mechanical compression and restoration. Among the possible therapies, tissue engineering of osteochondral tissues has shown considerable promise where multiple approaches of utilizing cells, scaffolds, and signaling molecules have been pursued. This review focuses particularly on the importance of scaffold design and its role in the success of osteochondral tissue engineering. Biphasic and gradient composition with proper pore configurations are the basic design consideration for scaffolds. Surface modification is an essential technique to improve the scaffold function associated with cell regulation or delivery of signaling molecules. The use of functional scaffolds with a controllable delivery strategy of multiple signaling molecules is also considered a promising therapeutic approach. In this review, we updated the recent advances in scaffolding approaches for osteochondral tissue engineering.

  8. Mindfulness, Physical Activity and Avoidance of Secondhand Smoke: A Study of College Students in Shanghai.

    Science.gov (United States)

    Gao, Yu; Shi, Lu

    2015-08-21

    To better understand the documented link between mindfulness and longevity, we examine the association between mindfulness and conscious avoidance of secondhand smoke (SHS), as well as the association between mindfulness and physical activity. In Shanghai University of Finance and Economics (SUFE) we surveyed a convenience sample of 1516 college freshmen. We measured mindfulness, weekly physical activity, and conscious avoidance of secondhand smoke, along with demographic and behavioral covariates. We used a multilevel logistic regression to test the association between mindfulness and conscious avoidance of secondhand smoke, and used a Tobit regression model to test the association between mindfulness and metabolic equivalent hours per week. In both models the home province of the student respondent was used as the cluster variable, and demographic and behavioral covariates, such as age, gender, smoking history, household registration status (urban vs. rural), the perceived smog frequency in their home towns, and the asthma diagnosis. The logistic regression of consciously avoiding SHS shows that a higher level of mindfulness was associated with an increase in the odds ratio of conscious SHS avoidance (logged odds: 0.22, standard error: 0.07, p active smoker. The observed associational patterns here are consistent with previous findings that mindfulness is associated with healthier behaviors in obesity prevention and substance use. Research designs with interventions are needed to test the causal link between mindfulness and these healthy behaviors.

  9. Effects of Mindfulness Interventions on Health Outcomes in Older Lesbian/Bisexual Women.

    Science.gov (United States)

    Ingraham, Natalie; Eliason, Michele J; Garbers, Samantha; Harbatkin, Dawn; Minnis, Alexandra M; McElroy, Jane A; Haynes, Suzanne G

    2016-07-07

    Lesbian and bisexual (LB) women are at higher risk for obesity, but no reported interventions focus on older LB women who are overweight or obese. The Healthy Weight in Lesbian and Bisexual Women study funded five programs (n = 266 LB women age ≥40); two examined effects of mindfulness interventions on health outcomes. Analysis of variance and regression measured the impact of mindfulness-based programs on health behaviors and quality of life (MCS). Outcomes were also compared between intervention sites (mindfulness vs. standard weight loss approaches). Mindful Eating Questionnaire (MEQ) subscale scores improved significantly from preassessment to postassessment in mindfulness interventions. LB women who reported an increase (top tertile) in mindful eating had the most significant increase in MCS scores (35.3%) compared with those with low gains (low and medium tertile) in mindfulness (3.8%). MEQ score increase predicted 40.8% of the variance (adjusted) in MCS score, R(2) = .431, F(6,145) = 18.337, p mindfulness were significantly related to increases in physical activity and some nutrition outcomes. Mindfulness intervention sites showed within-person improvements in MCS and fruit and vegetable intake, whereas standard intervention sites showed within-person decreases in alcohol intake and increases in physical activity level. Although weight loss was not a primary outcome at the mindfulness sites, small but significant weight loss and weight-to-height ratio decreases were reported at all five sites. Increases in mindfulness were associated with a number of significant self-reported health improvements, including a great increase in perceived mental health quality of life. Mindfulness may be a promising practice to address health issues in aging LB women. Copyright © 2016 Jacobs Institute of Women's Health. All rights reserved.

  10. Finite-element design and optimization of a three-dimensional tetrahedral porous titanium scaffold for the reconstruction of mandibular defects.

    Science.gov (United States)

    Luo, Danmei; Rong, Qiguo; Chen, Quan

    2017-09-01

    Reconstruction of segmental defects in the mandible remains a challenge for maxillofacial surgery. The use of porous scaffolds is a potential method for repairing these defects. Now, additive manufacturing techniques provide a solution for the fabrication of porous scaffolds with specific geometrical shapes and complex structures. The goal of this study was to design and optimize a three-dimensional tetrahedral titanium scaffold for the reconstruction of mandibular defects. With a fixed strut diameter of 0.45mm and a mean cell size of 2.2mm, a tetrahedral structural porous scaffold was designed for a simulated anatomical defect derived from computed tomography (CT) data of a human mandible. An optimization method based on the concept of uniform stress was performed on the initial scaffold to realize a minimal-weight design. Geometric and mechanical comparisons between the initial and optimized scaffold show that the optimized scaffold exhibits a larger porosity, 81.90%, as well as a more homogeneous stress distribution. These results demonstrate that tetrahedral structural titanium scaffolds are feasible structures for repairing mandibular defects, and that the proposed optimization scheme has the ability to produce superior scaffolds for mandibular reconstruction with better stability, higher porosity, and less weight. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  11. In vitro and in vivo evaluation of carbonate apatite-collagen scaffolds with some cytokines for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Sherman Salim

    2015-01-01

    Results and Conclusion: By histological observation and measurement of bone area ratio, CA-CS with cytokines showed higher bone formation ability (bFGF/CA-CS: 50.7 ± 7.3%, rh-BMP2/CA-CS: 54.2 ± 5.0% than other groups. From the limited results of this study, it is suggested that CA collagen scaffolds with some cytokines may become an attractive scaffold for bone regeneration.

  12. Signs, dispositions, and semiotic scaffolding.

    Science.gov (United States)

    Fernández, Eliseo

    2015-12-01

    scaffolding. These interactions transpire between energetic causal chains and a wide range of converging semiotic transactions unfolding within each individual organism and between organisms and their environment. The perspective advanced here helps elucidate the manner in which physical and semiotic causation cooperate in an orchestrated fashion, giving rise to an ever-expanding profusion of scaffolding structures and processes. Using simple examples I outline some mechanisms that bring about this orchestration as well as the resultant channeling activities that eventually merge and find their culmination in the enactment of goal-oriented behavior. Copyright © 2015. Published by Elsevier Ltd.

  13. Setd7 and its contribution to boron-induced bone regeneration in B-MBG scaffolds.

    Science.gov (United States)

    Yin, Chengcheng; Jia, Xiaoshi; Miron, Richard J; Long, Qiaoyun; Xu, Hudi; Wei, Yan; Wu, Min; Zhang, Yufeng; Li, Zubing

    2018-04-20

    Boron (B), a trace element found in the human body, plays an important role for health of bone by promoting the proliferation and differentiation of osteoblasts. Our research group previously fabricated B-mesoporous bioactive glass (MBG) scaffolds, which successfully promoted osteogenic differentiation of osteoblasts when compared to pure MBG scaffolds without boron. However, the mechanisms of the positive effect of B-MBG scaffolds on osteogenesis remains unknown. Therefore, we performed in-vivo experiments in an OVX rat models with pure MBG scaffolds and compared them to B-MBG scaffold. As a result, we found that B-MBG scaffold induced more new bone regeneration compared to pure MBG scaffold and examined genes related to bone regeneration induced by B-MBG scaffold through RNA-seq to obtain target genes and epigenetic mechanisms. The results demonstrated an increased expression and affiliation of Setd7 in the B-MBG group when compared to the MBG group. Immunofluorescent staining from our in vivo samples further demonstrated a higher localization of Setd7 and H3K4me3 in Runx2-positive cells in defects treated with B-MBG scaffolds. KEGG results suggested that specifically Wnt/β-catenin signaling pathway was highly activated in new bone area associated with B-MBG scaffolds. Thereafter, in vitro studies with human bone marrow stem cells (hBMSCs) stimulated by extracted liquid of B-MBG was associated with significantly elevated levels of Setd7, as well as H3K4me3 when compared to MBG alone. To verify the role of Setd7 in new bone formation in the presence of Boron, Setd7 was knocked down in hBMSCs with stimulation of the extracted liquids of B-MBG or MBG scaffolds. The result showed that osteoblast differentiation of hBMSCs was inhibited when Setd7 was knocked down, which could not be rescued by the extract liquids of B-MBG scaffolds confirming its role in osteoblast differentiation and bone regeneration. As a histone methylase, Setd7 may be expected to be a potential

  14. Nanocomposite scaffolds with tunable mechanical and degradation capabilities: co-delivery of bioactive agents for bone tissue engineering.

    Science.gov (United States)

    Cattalini, Juan P; Roether, Judith; Hoppe, Alexander; Pishbin, Fatemeh; Haro Durand, Luis; Gorustovich, Alejandro; Boccaccini, Aldo R; Lucangioli, Silvia; Mouriño, Viviana

    2016-10-21

    Novel multifunctional nanocomposite scaffolds made of nanobioactive glass and alginate crosslinked with therapeutic ions such as calcium and copper were developed for delivering therapeutic agents, in a highly controlled and sustainable manner, for bone tissue engineering. Alendronate, a well-known antiresorptive agent, was formulated into microspheres under optimized conditions and effectively loaded within the novel multifunctional scaffolds with a high encapsulation percentage. The size of the cation used for the alginate crosslinking impacted directly on porosity and viscoelastic properties, and thus, on the degradation rate and the release profile of copper, calcium and alendronate. According to this, even though highly porous structures were created with suitable pore sizes for cell ingrowth and vascularization in both cases, copper-crosslinked scaffolds showed higher values of porosity, elastic modulus, degradation rate and the amount of copper and alendronate released, when compared with calcium-crosslinked scaffolds. In addition, in all cases, the scaffolds showed bioactivity and mechanical properties close to the endogenous trabecular bone tissue in terms of viscoelasticity. Furthermore, the scaffolds showed osteogenic and angiogenic properties on bone and endothelial cells, respectively, and the extracts of the biomaterials used promoted the formation of blood vessels in an ex vivo model. These new bioactive nanocomposite scaffolds represent an exciting new class of therapeutic cell delivery carrier with tunable mechanical and degradation properties; potentially useful in the controlled and sustainable delivery of therapeutic agents with active roles in bone formation and angiogenesis, as well as in the support of cell proliferation and osteogenesis for bone tissue engineering.

  15. The effect of porosity on cell ingrowth into accurately defined, laser-made, polylactide-based 3D scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Danilevicius, Paulius; Georgiadi, Leoni [Foundation for Research and Technology Hellas (FORTH), Institute of Electronic Structure and Laser (IESL), N Plastira 100, 70013 Heraklion (Greece); Pateman, Christopher J.; Claeyssens, Frederik [Kroto Research Institute, Department of Materials Science and Engineering, University of Sheffield, Broad Lane, Sheffield S3 7HQ (United Kingdom); Chatzinikolaidou, Maria, E-mail: mchatzin@materials.uoc.gr [Foundation for Research and Technology Hellas (FORTH), Institute of Electronic Structure and Laser (IESL), N Plastira 100, 70013 Heraklion (Greece); Department of Materials Science and Technology, University of Crete, PO Box 2208, 71303 Heraklion (Greece); Farsari, Maria, E-mail: mfarsari@iesl.forth.gr [Foundation for Research and Technology Hellas (FORTH), Institute of Electronic Structure and Laser (IESL), N Plastira 100, 70013 Heraklion (Greece)

    2015-05-01

    Highlights: • We studied the porosity of laser-made 3D scaffolds on MC3T3-E1 pre-osteoblastic cells. • We made polylactide 3D scaffolds with pores 25–110 μm. - Abstract: The aim of this study is to demonstrate the accuracy required for the investigation of the role of solid scaffolds’ porosity in cell proliferation. We therefore present a qualitative investigation into the effect of porosity on MC3T3-E1 pre-osteoblastic cell ingrowth of three-dimensional (3D) scaffolds fabricated by direct femtosecond laser writing. The material we used is a purpose made photosensitive pre-polymer based on polylactide. We designed and fabricated complex, geometry-controlled 3D scaffolds with pore sizes ranging from 25 to 110 μm, representing porosities 70%, 82%, 86%, and 90%. The 70% porosity scaffolds did not support cell growth initially and in the long term. For the other porosities, we found a strong adhesion of the pre-osteoblastic cells from the first hours after seeding and a remarkable proliferation increase after 3 weeks and up to 8 weeks. The 86% porosity scaffolds exhibited a higher efficiency compared to 82% and 90%. In addition, bulk material degradation studies showed that the employed, highly-acrylated polylactide is degradable. These findings support the potential use of the proposed material and the scaffold fabrication technique in bone tissue engineering.

  16. Microstructure, Mechanical Properties and Corrosion Behavior of Porous Mg-6 wt.% Zn Scaffolds for Bone Tissue Engineering

    Science.gov (United States)

    Yan, Yang; Kang, Yijun; Li, Ding; Yu, Kun; Xiao, Tao; Wang, Qiyuan; Deng, Youwen; Fang, Hongjie; Jiang, Dayue; Zhang, Yu

    2018-03-01

    Porous Mg-based scaffolds have been extensively researched as biodegradable implants due to their attractive biological and excellent mechanical properties. In this study, porous Mg-6 wt.% Zn scaffolds were prepared by powder metallurgy using ammonium bicarbonate particles as space-holder particles. The effects of space-holder particle content on the microstructure, mechanical properties and corrosion resistance of the Mg-6 wt.% Zn scaffolds were studied. The mean porosity and pore size of the open-cellular scaffolds were within the range 6.7-52.2% and 32.3-384.2 µm, respectively. Slight oxidation was observed at the grain boundaries and on the pore walls. The Mg-6 wt.% Zn scaffolds were shown to possess mechanical properties comparable with those of natural bone and had variable in vitro degradation rates. Increased content of space-holder particles negatively affected the mechanical behavior and corrosion resistance of the Mg-6 wt.% Zn scaffolds, especially when higher than 20%. These results suggest that porous Mg-6 wt.% Zn scaffolds are promising materials for application in bone tissue engineering.

  17. Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Soumyaranjan; Sanger, Kuldeep; Heiskanen, Arto [DTU Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads, DK-2800 Kgs. Lyngby (Denmark); Trifol, Jon; Szabo, Peter [Danish Polymer Centre, Department of Chemical and Biochemical Engineering, Søltofts Plads, Building 229, DK-2800 Kgs. Lyngby (Denmark); Dufva, Marin; Emnéus, Jenny [DTU Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads, DK-2800 Kgs. Lyngby (Denmark); Wolff, Anders, E-mail: anders.wolff@nanotech.dtu.dk [DTU Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads, DK-2800 Kgs. Lyngby (Denmark)

    2016-04-01

    Limitations in controlling scaffold architecture using traditional fabrication techniques are a problem when constructing engineered tissues/organs. Recently, integration of two pore architectures to generate dual-pore scaffolds with tailored physical properties has attracted wide attention in tissue engineering community. Such scaffolds features primary structured pores which can efficiently enhance nutrient/oxygen supply to the surrounding, in combination with secondary random pores, which give high surface area for cell adhesion and proliferation. Here, we present a new technique to fabricate dual-pore scaffolds for various tissue engineering applications where 3D printing of poly(vinyl alcohol) (PVA) mould is combined with salt leaching process. In this technique the sacrificial PVA mould, determining the structured pore architecture, was filled with salt crystals to define the random pore regions of the scaffold. After crosslinking the casted polymer the combined PVA-salt mould was dissolved in water. The technique has advantages over previously reported ones, such as automated assembly of the sacrificial mould, and precise control over pore architecture/dimensions by 3D printing parameters. In this study, polydimethylsiloxane and biodegradable poly(ϵ-caprolactone) were used for fabrication. However, we show that this technique is also suitable for other biocompatible/biodegradable polymers. Various physical and mechanical properties of the dual-pore scaffolds were compared with control scaffolds with either only structured or only random pores, fabricated using previously reported methods. The fabricated dual-pore scaffolds supported high cell density, due to the random pores, in combination with uniform cell distribution throughout the scaffold, and higher cell proliferation and viability due to efficient nutrient/oxygen transport through the structured pores. In conclusion, the described fabrication technique is rapid, inexpensive, scalable, and compatible

  18. Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching

    International Nuclear Information System (INIS)

    Mohanty, Soumyaranjan; Sanger, Kuldeep; Heiskanen, Arto; Trifol, Jon; Szabo, Peter; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2016-01-01

    Limitations in controlling scaffold architecture using traditional fabrication techniques are a problem when constructing engineered tissues/organs. Recently, integration of two pore architectures to generate dual-pore scaffolds with tailored physical properties has attracted wide attention in tissue engineering community. Such scaffolds features primary structured pores which can efficiently enhance nutrient/oxygen supply to the surrounding, in combination with secondary random pores, which give high surface area for cell adhesion and proliferation. Here, we present a new technique to fabricate dual-pore scaffolds for various tissue engineering applications where 3D printing of poly(vinyl alcohol) (PVA) mould is combined with salt leaching process. In this technique the sacrificial PVA mould, determining the structured pore architecture, was filled with salt crystals to define the random pore regions of the scaffold. After crosslinking the casted polymer the combined PVA-salt mould was dissolved in water. The technique has advantages over previously reported ones, such as automated assembly of the sacrificial mould, and precise control over pore architecture/dimensions by 3D printing parameters. In this study, polydimethylsiloxane and biodegradable poly(ϵ-caprolactone) were used for fabrication. However, we show that this technique is also suitable for other biocompatible/biodegradable polymers. Various physical and mechanical properties of the dual-pore scaffolds were compared with control scaffolds with either only structured or only random pores, fabricated using previously reported methods. The fabricated dual-pore scaffolds supported high cell density, due to the random pores, in combination with uniform cell distribution throughout the scaffold, and higher cell proliferation and viability due to efficient nutrient/oxygen transport through the structured pores. In conclusion, the described fabrication technique is rapid, inexpensive, scalable, and compatible

  19. 2-N, 6-O-sulfated chitosan-assisted BMP-2 immobilization of PCL scaffolds for enhanced osteoinduction

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Lingyan [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); CSIRO Manufacturing, Bayview Avenue, Clayton, Victoria 3168 (Australia); Department of Prosthodontics, College of Stomatology, Ninth People' s Hospital, School of Medicine, Shanghai Jiao Tong University, 639 Zhizaoju Road, Shanghai 200011 (China); Yu, Yuanman [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Wang, Jing, E-mail: biomatwj@163.com [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Werkmeister, Jerome A [CSIRO Manufacturing, Bayview Avenue, Clayton, Victoria 3168 (Australia); McLean, Keith M, E-mail: Keith.McLean@csiro.au [CSIRO Manufacturing, Bayview Avenue, Clayton, Victoria 3168 (Australia); Liu, Changsheng, E-mail: liucs@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China)

    2017-05-01

    The aim of this study was to develop a 2-N, 6-O-sulfated chitosan (26SCS) modified electrospun fibrous PCL scaffold for bone morphogenetic protein-2 (BMP-2) delivery to improve osteoinduction. The PCL scaffold was modified by an aminolysis reaction using ethylenediamine (ED) and 26SCS was immobilized via electrostatic interactions (PCL-N-S). Scaffolds were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements. In vitro BMP-2 adsorption and release kinetics indicated that modified PCL-N-S scaffolds showed higher levels of binding of BMP-2 (about 30–100 times), moderative burst release (about one third), and prolonged releasing time compared to the unmodified PCL scaffold. The bioactivity of released BMP-2 determined by alkaline phosphatase (ALP) activity assay was maintained and improved 8– 12 times with increasing concentration of immobilized 26SCS on the scaffolds. In vitro studies demonstrated that bone marrow mesenchymal stem cells (BMSCs) attached more readily to the PCL-N-S scaffolds with increased spreading. In conclusion, 26SCS modified PCL scaffolds can be a potent system for the sustained and bioactive delivery of BMP-2. - Graphical abstract: Limited self-regenerating capacity of human body makes the reconstruction of critical size bone defect a significant challenge. Although bone morphogenetic protein-2 (BMP-2) is an important differentiation factor inducing bone regeneration, it's short half-life in vivo and potent side effect at high dosage still show lots of concerns in the clinical use. Herein, modification of electrospun PCL scaffolds was presented through immobilizing of sulfated chitosan (26SCS). The modified scaffolds effectively improve the binding capacity of BMP-2 and exhibited an enhanced bioactivity and sustained release in vitro. Thus, the use of 26SCS modified PCL scaffolds combined with BMP-2 could be a useful scaffold for tissue

  20. Baby MIND Experiment Construction Status

    Energy Technology Data Exchange (ETDEWEB)

    Antonova, M.; et al.

    2017-04-28

    Baby MIND is a magnetized iron neutrino detector, with novel design features, and is planned to serve as a downstream magnetized muon spectrometer for the WAGASCI experiment on the T2K neutrino beam line in Japan. One of the main goals of this experiment is to reduce systematic uncertainties relevant to CP-violation searches, by measuring the neutrino contamination in the anti-neutrino beam mode of T2K. Baby MIND is currently being constructed at CERN, and is planned to be operational in Japan in October 2017.

  1. Digitalization of the human mind

    OpenAIRE

    Mr.Sc. Drita Mehmeti

    2013-01-01

    The human faces with various problems already in its first steps in live, and carriers of such life situations are found in various ages which bring new currents in the way of life. Starting from the ancient Greek thought, the human and its mind made the centre of the world, already orienting the Western thought towards the study of the human mind (namely human reason), since it made the key tool for human survival. Although human problems have been discussed throughout various ages, they hav...

  2. Relationship between meditative practice and self-reported mindfulness: the MINDSENS composite index.

    Directory of Open Access Journals (Sweden)

    Joaquim Soler

    Full Text Available Mindfulness has been described as an inherent human capability that can be learned and trained, and its improvement has been associated with better health outcomes in both medicine and psychology. Although the role of practice is central to most mindfulness programs, practice-related improvements in mindfulness skills is not consistently reported and little is known about how the characteristics of meditative practice affect different components of mindfulness. The present study explores the role of practice parameters on self-reported mindfulness skills. A total of 670 voluntary participants with and without previous meditation experience (n = 384 and n = 286, respectively responded to an internet-based survey on various aspects of their meditative practice (type of meditation, length of session, frequency, and lifetime practice. Participants also completed the Five Facets Mindfulness Questionnaire (FFMQ, and the Experiences Questionnaire (EQ. The group with meditation experience obtained significantly higher scores on all facets of FFMQ and EQ questionnaires compared to the group without experience. However different effect sizes were observed, with stronger effects for the Observing and Non-Reactivity facets of the FFMQ, moderate effects for Decentering in EQ, and a weak effect for Non-judging, Describing, and Acting with awareness on the FFMQ. Our results indicate that not all practice variables are equally relevant in terms of developing mindfulness skills. Frequency and lifetime practice--but not session length or meditation type--were associated with higher mindfulness skills. Given that these 6 mindfulness aspects show variable sensitivity to practice, we created a composite index (MINDSENS consisting of those items from FFMQ and EQ that showed the strongest response to practice. The MINDSENS index was able to correctly discriminate daily meditators from non-meditators in 82.3% of cases. These findings may contribute to the understanding

  3. Relationship between meditative practice and self-reported mindfulness: the MINDSENS composite index.

    Science.gov (United States)

    Soler, Joaquim; Cebolla, Ausiàs; Feliu-Soler, Albert; Demarzo, Marcelo M P; Pascual, Juan C; Baños, Rosa; García-Campayo, Javier

    2014-01-01

    Mindfulness has been described as an inherent human capability that can be learned and trained, and its improvement has been associated with better health outcomes in both medicine and psychology. Although the role of practice is central to most mindfulness programs, practice-related improvements in mindfulness skills is not consistently reported and little is known about how the characteristics of meditative practice affect different components of mindfulness. The present study explores the role of practice parameters on self-reported mindfulness skills. A total of 670 voluntary participants with and without previous meditation experience (n = 384 and n = 286, respectively) responded to an internet-based survey on various aspects of their meditative practice (type of meditation, length of session, frequency, and lifetime practice). Participants also completed the Five Facets Mindfulness Questionnaire (FFMQ), and the Experiences Questionnaire (EQ). The group with meditation experience obtained significantly higher scores on all facets of FFMQ and EQ questionnaires compared to the group without experience. However different effect sizes were observed, with stronger effects for the Observing and Non-Reactivity facets of the FFMQ, moderate effects for Decentering in EQ, and a weak effect for Non-judging, Describing, and Acting with awareness on the FFMQ. Our results indicate that not all practice variables are equally relevant in terms of developing mindfulness skills. Frequency and lifetime practice--but not session length or meditation type--were associated with higher mindfulness skills. Given that these 6 mindfulness aspects show variable sensitivity to practice, we created a composite index (MINDSENS) consisting of those items from FFMQ and EQ that showed the strongest response to practice. The MINDSENS index was able to correctly discriminate daily meditators from non-meditators in 82.3% of cases. These findings may contribute to the understanding of the

  4. Osteoinduction and proliferation of bone-marrow stromal cells in three-dimensional poly (ε-caprolactone)/ hydroxyapatite/collagen scaffolds.

    Science.gov (United States)

    Wang, Ting; Yang, Xiaoyan; Qi, Xin; Jiang, Chaoyin

    2015-05-08

    Osteoinduction and proliferation of bone-marrow stromal cells (BMSCs) in three-dimensional (3D) poly(ε-caprolactone) (PCL) scaffolds have not been studied throughly and are technically challenging. This study aimed to optimize nanocomposites of 3D PCL scaffolds to provide superior adhesion, proliferation and differentiation environment for BMSCs in this scenario. BMSCs were isolated and cultured in a novel 3D tissue culture poly(ε-caprolactone) (PCL) scaffold coated with poly-lysine, hydroxyapatite (HAp), collagen and HAp/collagen. Cell morphology was observed and BMSC biomarkers for osteogenesis, osteoblast differentiation and activation were analyzed. Scanning Electron Microscope (SEM) micrographs showed that coating materials were uniformly deposited on the surface of PCL scaffolds and BMSCs grew and aggregated to form clusters during 3D culture. Both mRNA and protein levels of the key players of osteogenesis and osteoblast differentiation and activation, including runt-related transcription factor 2 (Runx2), alkaline phosphates (ALP), osterix, osteocalcin, and RANKL, were significantly higher in BMSCs seeded in PCL scaffolds coated with HAp or HAp/collagen than those seeded in uncoated PCL scaffolds, whereas the expression levels were not significantly different in collagen or poly-lysine coated PCL scaffolds. In addition, poly-lysine, collagen, HAp/collagen, and HAp coated PCL scaffolds had significantly more viable cells than uncoated PCL scaffolds, especially scaffolds with HAp/collagen and collagen-alone coatings. That BMSCs in HAp or HAp/collagen PCL scaffolds had remarkably higher ALP activities than those in collagen-coated alone or uncoated PCL scaffolds indicating higher osteogenic differentiation levels of BMSCs in HAp or HAp/collagen PCL scaffolds. Moreover, morphological changes of BMSCs after four-week of 3D culture confirmed that BMSCs successfully differentiated into osteoblast with spread-out phenotype in HAp/collagen coated PCL scaffolds

  5. To Mind IT or not to Mind IT

    DEFF Research Database (Denmark)

    Zinner Henriksen, Helle; Rukonova, Boriana

    2011-01-01

    interpretative research approaches to less explored domains. It highlights that practitioners perceive certain variables, which are less obvious to the traditional research-driven models, to be of importance. Practical implications – The results should be applied with care, bearing in mind that our conclusions...

  6. Mindful Storytellers: Emerging Pragmatics and Theory of Mind Development

    Science.gov (United States)

    Fernández, Camila

    2013-01-01

    Emerging pragmatic language skills involve social, cognitive and linguistic abilities, including children's awareness of the conversational partner's mental states. The present study investigated the relation between children's theory of mind (ToM) and features of pragmatic language skills assessed through narrative discourse. One hundred and…

  7. Neurotheology-Matters of the Mind or Matters that Mind?

    Science.gov (United States)

    Shukla, Samarth; Acharya, Sourya; Rajput, Devendra

    2013-07-01

    Understanding the true nature of an individual, be it a child or an adult, a male or a female, is almost an impossible task. The vast abyss like behaviour of a human mind is virtually unfathomable. Yet, with the advent of neurosciences, it can be said that we, as the medical fraternity, have been in a position to decipher a considerable part of the human mind. This review accepts the fact that religion and theology have extreme reverence and respect. Yet, when it comes to extraordinary beliefs, phenomena, unimaginable feats and emotional deviations of the human mind, especially those which involve deep faiths and beliefs, comprehensive neuroscientific explanations from the emerging data, with the aid of elaborate neuroimaging, have proved to be extremely rational and logical. This review did make an attempt to untangle some facets of spirituality and to make rational explanations of the same. It was an attempt to understand the function of the mind (as an abstract) and the brain, on the spiritual experiences and sudden enlightments, the experience of togetherness with the universe, and to understand the phenomena of trance and an altered state of consciousness, which is better referred as the emerging science of neurotheology.

  8. Tubular inverse opal scaffolds for biomimetic vessels

    Science.gov (United States)

    Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

    2016-07-01

    There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

  9. DNA-scaffolded nanoparticle structures

    Energy Technology Data Exchange (ETDEWEB)

    Hoegberg, Bjoern; Olin, Haakan [Department of Engineering Physics and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, Sweden (Sweden)

    2007-03-15

    DNA self-assembly is a powerful route to the production of very small, complex structures. When used in combination with nanoparticles it is likely to become a key technology in the production of nanoelectronics in the future. Previously, demonstrated nanoparticle assemblies have mainly been periodic and highly symmetric arrays, unsuited as building blocks for any complex circuits. With the invention of DNA-scaffolded origami reported earlier this year (Rothemund P W K 2006 Nature 440 (7082) 297-302), a new route to complex nanostructures using DNA has been opened. Here, we give a short review of the field and present the current status of our experiments were DNA origami is used in conjunction with nanoparticles. Gold nanoparticles are functionalized with thiolated single stranded DNA. Strands that are complementary to the gold particle strands can be positioned on the self-assembled DNA-structure in arbitrary patterns. This property should allow an accurate positioning of the particles by letting them hybridize on the lattice. We report on our recent experiments on this system and discuss open problems and future applications.

  10. DNA-scaffolded nanoparticle structures

    International Nuclear Information System (INIS)

    Hoegberg, Bjoern; Olin, Haakan

    2007-01-01

    DNA self-assembly is a powerful route to the production of very small, complex structures. When used in combination with nanoparticles it is likely to become a key technology in the production of nanoelectronics in the future. Previously, demonstrated nanoparticle assemblies have mainly been periodic and highly symmetric arrays, unsuited as building blocks for any complex circuits. With the invention of DNA-scaffolded origami reported earlier this year (Rothemund P W K 2006 Nature 440 (7082) 297-302), a new route to complex nanostructures using DNA has been opened. Here, we give a short review of the field and present the current status of our experiments were DNA origami is used in conjunction with nanoparticles. Gold nanoparticles are functionalized with thiolated single stranded DNA. Strands that are complementary to the gold particle strands can be positioned on the self-assembled DNA-structure in arbitrary patterns. This property should allow an accurate positioning of the particles by letting them hybridize on the lattice. We report on our recent experiments on this system and discuss open problems and future applications

  11. Towards an ideal polymer scaffold for tendon/ligament tissue engineering

    Science.gov (United States)

    Sahoo, Sambit; Ouyang, Hong Wei; Goh, James Cho-Hong; Tay, Tong-Earn; Toh, Siew Lok

    2005-04-01

    Tissue engineering holds promise in treating injured tendons and ligaments by replacing the injured tissues with "engineered tissues" with identical mechanical and functional characteristics. A biocompatible, biodegradable, porous scaffold with optimized architecture, sufficient surface area for cell attachment, growth and proliferation, faborable mechanical properties, and suitable degradation rate is a pre-requisite to achieve success with this aproach. Knitted poly(lactide-co-glycolide) (PLGA) scaffolds comprising of microfibers of 25 micron diameter were coated with PLGA nanofibers on their surfaces by electrospinning technique. A cell suspension of pig bone marrow stromal cells (BMSC) was seeded on the scaffolds by pipetting, and the cell-scaffold constructs were cultured in a CO2 incubator, at 37°C for 1-2 weeks. The "engineered tissues" were then assessed for cell attachment and proliferation, tissue formation, and mechanical properties. Nanofibers, of diameter 300-900 nm, were spread randomly over the knitted scaffold. The reduction in pore-size from about 1 mm (in the knitted scaffold) to a few micrometers (in the nano-microscaffold) allowed cell seeding by direct pipetting, and eliminated the need of a cell-delivery system like fibrin gel. BMSCs were seen to attach and proliferate well on the nano-microscaffold, producing abundant extracellular matrix. Mechanical testing revealed that the cell-seeded nano-microscaffolds possessed slightly higher values of failure load, elastic-region stiffness and toe-region stiffness, than the unseeded scaffolds. The combination of superior mechanical strength and integrity of knitted microfibers, with the large surface area and improved hydrophilicity of the electrospun nanofibers facilitated cell attachment and new tissue formation. This holds promise in tissue engineering of tendon/ligament.

  12. Wetspun poly-L-(lactic acid)-borosilicate bioactive glass scaffolds for guided bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, João S., E-mail: joao.fernandes@dep.uminho.pt [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga/Guimarães (Portugal); Reis, Rui L. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga/Guimarães (Portugal); Pires, Ricardo A., E-mail: rpires@dep.uminho.pt [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga/Guimarães (Portugal)

    2017-02-01

    We developed a porous poly-L-lactic acid (PLLA) scaffold compounded with borosilicate bioactive glasses (BBGs) endowing it with bioactive properties. Porous PLLA-BBG fibre mesh scaffolds were successfully prepared by the combination of wet spinning and fibre bonding techniques. Micro-computed tomography (μCT) confirmed that the PLLA-BBG scaffolds containing ≈ 25% of BBGs (w/w) exhibited randomly interconnected porous (58 to 62% of interconnectivity and 53 to 67% of porosity) with mean pore diameters higher that 100 μm. Bioactivity and degradation studies were performed by immersing the scaffolds in simulated body fluid (SBF) and ultrapure water, respectively. The PLLA-BBG scaffolds presented a faster degradation rate with a constant release of inorganic species, which are capable to produce calcium phosphate structures at the surface of the material after 7 days of immersion in SBF (Ca/P ratio of ~ 1.7). Cellular in vitro studies with human osteosarcoma cell line (Saos-2) and human adipose-derived stem cells (hASCs) showed that PLLA-BBGs are not cytotoxic to cells, while demonstrating their capacity to promote cell adhesion and proliferation. Overall, we showed that the proposed scaffolds present a tailored kinetics on the release of inorganic species and controlled biological response under conditions that mimic the bone physiological environment. - Highlights: • We prepared borosilicate glasses and their PLLA composites in the form of fibres. • These glasses imparted bioactivity and controlled degradability to the fibres. • The prepared fibres did not elicit cytotoxicity. • hASCs attached and proliferated in the surface and inner sections of the scaffolds. • The composites present appropriate properties to be used in bone tissue engineering.

  13. Wetspun poly-L-(lactic acid)-borosilicate bioactive glass scaffolds for guided bone regeneration

    International Nuclear Information System (INIS)

    Fernandes, João S.; Reis, Rui L.; Pires, Ricardo A.

    2017-01-01

    We developed a porous poly-L-lactic acid (PLLA) scaffold compounded with borosilicate bioactive glasses (BBGs) endowing it with bioactive properties. Porous PLLA-BBG fibre mesh scaffolds were successfully prepared by the combination of wet spinning and fibre bonding techniques. Micro-computed tomography (μCT) confirmed that the PLLA-BBG scaffolds containing ≈ 25% of BBGs (w/w) exhibited randomly interconnected porous (58 to 62% of interconnectivity and 53 to 67% of porosity) with mean pore diameters higher that 100 μm. Bioactivity and degradation studies were performed by immersing the scaffolds in simulated body fluid (SBF) and ultrapure water, respectively. The PLLA-BBG scaffolds presented a faster degradation rate with a constant release of inorganic species, which are capable to produce calcium phosphate structures at the surface of the material after 7 days of immersion in SBF (Ca/P ratio of ~ 1.7). Cellular in vitro studies with human osteosarcoma cell line (Saos-2) and human adipose-derived stem cells (hASCs) showed that PLLA-BBGs are not cytotoxic to cells, while demonstrating their capacity to promote cell adhesion and proliferation. Overall, we showed that the proposed scaffolds present a tailored kinetics on the release of inorganic species and controlled biological response under conditions that mimic the bone physiological environment. - Highlights: • We prepared borosilicate glasses and their PLLA composites in the form of fibres. • These glasses imparted bioactivity and controlled degradability to the fibres. • The prepared fibres did not elicit cytotoxicity. • hASCs attached and proliferated in the surface and inner sections of the scaffolds. • The composites present appropriate properties to be used in bone tissue engineering.

  14. Modifying bone scaffold architecture in vivo with permanent magnets to facilitate fixation of magnetic scaffolds.

    Science.gov (United States)

    Panseri, S; Russo, A; Sartori, M; Giavaresi, G; Sandri, M; Fini, M; Maltarello, M C; Shelyakova, T; Ortolani, A; Visani, A; Dediu, V; Tampieri, A; Marcacci, M

    2013-10-01

    The fundamental elements of tissue regeneration are cells, biochemical signals and the three-dimensional microenvironment. In the described approach, biomineralized-collagen biomaterial functions as a scaffold and provides biochemical stimuli for tissue regeneration. In addition superparamagnetic nanoparticles were used to magnetize the biomaterials with direct nucleation on collagen fibres or impregnation techniques. Minimally invasive surgery was performed on 12 rabbits to implant cylindrical NdFeB magnets in close proximity to magnetic scaffolds within the lateral condyles of the distal femoral epiphyses. Under this static magnetic field we demonstrated, for the first time in vivo, that the ability to modify the scaffold architecture could influence tissue regeneration obtaining a well-ordered tissue. Moreover, the association between NdFeB magnet and magnetic scaffolds represents a potential technique to ensure scaffold fixation avoiding micromotion at the tissue/biomaterial interface. © 2013.

  15. Electrospun polyurethane/hydroxyapatite bioactive scaffolds for bone tissue engineering: the role of solvent and hydroxyapatite particles.

    Science.gov (United States)

    Tetteh, G; Khan, A S; Delaine-Smith, R M; Reilly, G C; Rehman, I U

    2014-11-01

    Polyurethane (PU) is a promising polymer to support bone-matrix producing cells due to its durability and mechanical resistance. In this study two types of medical grade poly-ether urethanes Z3A1 and Z9A1 and PU-Hydroxyapatite (PU-HA) composites were investigated for their ability to act as a scaffold for tissue engineered bone. PU dissolved in varying concentrations of dimethylformamide (DMF) and tetrahydrofuran (THF) solvents were electrospun to attain scaffolds with randomly orientated non-woven fibres. Bioactive polymeric composite scaffolds were created using 15 wt% Z3A1 in a 70/30 DMF/THF PU solution and incorporating micro- or nano-sized HA particles in a ratio of 3:1 respectively, whilst a 25 wt% Z9A1 PU solution was doped in ratio of 5:1. Chemical properties of the resulting composites were evaluated by FTIR and physical properties by SEM. Tensile mechanical testing was carried out on all electrospun scaffolds. MLO-A5 osteoblastic mouse cells and human embryonic mesenchymal progenitor cells, hES-MPs were seeded on the scaffolds to test their biocompatibility and ability to support mineralised matrix production over a 28 day culture period. Cell viability was assayed by MTT and calcium and collagen deposition by Sirius red and alizarin red respectively. SEM images of both electrospun PU scaffolds and PU-HA composite scaffolds showed differences in fibre morphology with changes in solvent combinations and size of HA particles. Inclusion of THF eliminated the presence of beads in fibres that were present in scaffolds fabricated with 100% DMF solvent, and resulted in fibres with a more uniform morphology and thicker diameters. Mechanical testing demonstrated that the Young׳s Modulus and yield strength was lower at higher THF concentrations. Inclusion of both sizes of HA particles in PU-HA solutions reinforced the scaffolds leading to higher mechanical properties, whilst FTIR characterisation confirmed the presence of HA in all composite scaffolds. Although

  16. Biodegradable Polymer-Based Scaffolds for Bone Tissue Engineering

    CERN Document Server

    Sultana, Naznin

    2013-01-01

    This book addresses the principles, methods and applications of biodegradable polymer based scaffolds for bone tissue engineering. The general principle of bone tissue engineering is reviewed and the traditional and novel scaffolding materials, their properties and scaffold fabrication techniques are explored. By acting as temporary synthetic extracellular matrices for cell accommodation, proliferation, and differentiation, scaffolds play a pivotal role in tissue engineering. This book does not only provide the comprehensive summary of the current trends in scaffolding design but also presents the new trends and directions for scaffold development for the ever expanding tissue engineering applications.

  17. Mindfulness is associated with psychological health and moderates pain in knee osteoarthritis.

    Science.gov (United States)

    Lee, A C; Harvey, W F; Price, L L; Morgan, L P K; Morgan, N L; Wang, C

    2017-06-01

    Previous studies suggest that higher mindfulness is associated with less pain and depression. However, the role of mindfulness has never been studied in knee osteoarthritis (OA). We evaluate the relationships between mindfulness and pain, psychological symptoms, and quality of life in knee OA. We performed a secondary analysis of baseline data from our randomized comparative trial in participants with knee OA. Mindfulness was assessed using the Five Facet Mindfulness Questionnaire (FFMQ). We measured pain, physical function, quality of life, depression, stress, and self-efficacy with commonly-used patient-reported measures. Simple and multivariable regression models were utilized to assess associations between mindfulness and health outcomes. We further tested whether mindfulness moderated the pain-psychological outcome associations. Eighty patients were enrolled (60.3 ± 10.3 years; 76.3% female, body mass index: 33.0 ± 7.1 kg/m 2 ). Total mindfulness score was associated with mental (beta = 1.31, 95% CI: 0.68, 1.95) and physical (beta = 0.69, 95% CI:0.06, 1.31) component quality of life, self-efficacy (beta = 0.22, 95% CI:0.07, 0.37), depression (beta = -1.15, 95% CI:-1.77, -0.54), and stress (beta = -1.07, 95% CI:-1.53, -0.60). Of the five facets, the Describing, Acting-with-Awareness, and Non-judging mindfulness facets had the most associations with psychological health. No significant association was found between mindfulness and pain or function (P = 0.08-0.24). However, we found that mindfulness moderated the effect of pain on stress (P = 0.02). Mindfulness is associated with depression, stress, self-efficacy, and quality of life among knee OA patients. Mindfulness also moderates the influence of pain on stress, which suggests that mindfulness may alter the way one copes with pain. Future studies examining the benefits of mind-body therapy, designed to increase mindfulness, for patients with OA are warranted. Copyright © 2016

  18. Cultivate Mindfulness: A Case Study of Mindful Learning in an English as a Foreign Language Classroom

    Science.gov (United States)

    Wang, Yang; Liu, Chao

    2016-01-01

    This case study investigated how the use of mindfulness affected college English as a foreign language (EFL) students' learning and how mindful learning strategies supported their learning of English. Mindful learning considers the students' abilities to be aware, perceive and conceive. Mindfulness results in an increase in competence, memory,…

  19. The reflective mind

    DEFF Research Database (Denmark)

    Vartanian, Oshin; Beatty, Erin; Smith, Ingrid

    2018-01-01

    problems were associated with greater activation in the ACC—a key region for conflict detection—even in cases when participants responded stereotypically. In participants with higher CRT scores, conflict problems were associated with greater activation in the posterior cingulate cortex (PCC...

  20. The psychometric properties of the Mindful Attention Awareness Scale (MAAS and Freiburg Mindfulness Inventory (FMI as measures of mindfulness and their relationship with burnout and work engagement

    Directory of Open Access Journals (Sweden)

    Martina Kotzé

    2016-10-01

    that the two instruments are moderately correlated, providing adequate evidence of convergent validity. With regards to predictive validity, both the FMI and MAAS showed statistically significant relations with burnout and work engagement. Yet, the MAAS showed higher correlations with these constructs. A similar picture emerged with regards to the stepwise multiple regression results. The MAAS was the only significant predictor of burnout, explaining 12% of the variance. Both the MAAS and FMI were significant predictors of work engagement. The MAAS explained 13% of the variance in work engagement while the FMI explained 3% of the variance. Practical/managerial implications: Given these results, the MAAS currently seems to be a more appropriate measurement of mindfulness in the workplace given its ability to better predict work engagement and burnout than the FMI. Contribution/value-add: The study has provided much needed empirical evidence on the psychometric properties of the FMI and MAAS as measures of mindfulness on a South African sample.

  1. Evaluation of Posterolateral Lumbar Fusion in Sheep Using Mineral Scaffolds Seeded with Cultured Bone Marrow Cells

    Directory of Open Access Journals (Sweden)

    María D. Cuenca-López

    2014-12-01

    Full Text Available The objective of this study is to investigate the efficacy of hybrid constructs in comparison to bone grafts (autograft and allograft for posterolateral lumbar fusion (PLF in sheep, instrumented with transpedicular screws and bars. Hybrid constructs using cultured bone marrow (BM mesenchymal stem cells (MSCs have shown promising results in several bone healing models. In particular, hybrid constructs made by calcium phosphate-enriched cells have had similar fusion rates to bone autografts in posterolateral lumbar fusion in sheep. In our study, four experimental spinal fusions in two animal groups were compared in sheep: autograft and allograft (reference group, hydroxyapatite scaffold, and hydroxyapatite scaffold seeded with cultured and osteoinduced bone marrow MSCs (hybrid construct. During the last three days of culture, dexamethasone (dex and beta-glycerophosphate (β-GP were added to potentiate osteoinduction. The two experimental situations of each group were tested in the same spinal segment (L4–L5. Spinal fusion and bone formation were studied by clinical observation, X-ray, computed tomography (CT, histology, and histomorphometry. Lumbar fusion rates assessed by CT scan and histology were higher for autograft and allograft (70% than for mineral scaffold alone (22% and hybrid constructs (35%. The quantity of new bone formation was also higher for the reference group, quite similar in both (autograft and allograft. Although the hybrid scaffold group had a better fusion rate than the non-hybrid scaffold group, the histological analysis revealed no significant differences between them in terms of quantity of bone formation. The histology results suggested that mineral scaffolds were partly resorbed in an early phase, and included in callus tissues. Far from the callus area the hydroxyapatite alone did not generate bone around it, but the hybrid scaffold did. In nude mice, labeled cells were induced to differentiate in vivo and monitored

  2. [Mechanical properties of polylactic acid/beta-tricalcium phosphate composite scaffold with double channels based on three-dimensional printing technique].

    Science.gov (United States)

    Lian, Qin; Zhuang, Pei; Li, Changhai; Jin, Zhongmin; Li, Dichen

    2014-03-01

    To improve the poor mechanical strength of porous ceramic scaffold, an integrated method based on three-dimensional (3-D) printing technique is developed to incorporate the controlled double-channel porous structure into the polylactic acid/beta-tricalcium phosphate (PLA/beta-TCP) reinforced composite scaffolds (double-channel composite scaffold) to improve their tissue regeneration capability and the mechanical properties. The designed double-channel structure inside the ceramic scaffold consisted of both primary and secondary micropipes, which parallel but un-connected. The set of primary channels was used for cell ingrowth, while the set of secondary channels was used for the PLA perfusion. Integration technology of 3-D printing technique and gel-casting was firstly used to fabricate the double-channel ceramic scaffolds. PLA/beta-TCP composite scaffolds were obtained by the polymer gravity perfusion process to pour PLA solution into the double-channel ceramic scaffolds through the secondary channel set. Microscope, porosity, and mechanical experiments for the standard samples were used to evaluate the composite properties. The ceramic scaffold with only the primary channel (single-channel scaffold) was also prepared as a control. Morphology observation results showed that there was no PLA inside the primary channels of the double-channel composite scaffolds but a dense interface layer between PLA and beta-TCP obviously formed on the inner wall of the secondary channels by the PLA penetration during the perfusion process. Finite element simulation found that the compressive strength of the double-channel composite scaffold was less than that of the single-channel scaffold; however, mechanical tests found that the maximum compressive strength of the double-channel composite scaffold [(21.25 +/- 1.15) MPa] was higher than that of the single-channel scaffold[ (9.76 +/- 0.64) MPa]. The double-channel composite scaffolds fabricated by 3-D printing technique have

  3. Manufacture of β-TCP/alginate scaffolds through a Fab@home model for application in bone tissue engineering

    International Nuclear Information System (INIS)

    Diogo, G S; Gaspar, V M; Serra, I R; Fradique, R; Correia, I J

    2014-01-01

    The growing need to treat bone-related diseases in an elderly population compels the development of novel bone substitutes to improve patient quality of life. In this context, the advent of affordable and effective rapid prototyping equipment, such as the Fab@home plotter, has contributed to the development of novel scaffolds for bone tissue engineering. In this study, we report for the first time the use of a Fab@home plotter for the production of 3D scaffolds composed by beta-tricalcium phosphate (β-TCP)/alginate hybrid materials. β-TCP/alginate mixtures were used in a proportion of 50/50% (w/w), 30/70% (w/w) and 20/80% (w/w). The printing parameters were optimized to a nozzle diameter of 20 Gauge for the production of rigid scaffolds with pre-defined architectures. We observed that, despite using similar printing parameters, both the precision and resolution of the scaffolds were significantly affected by the blend's viscosity. In particular, we demonstrate that the higher viscosity of 50/50 scaffolds (150.0 ± 3.91 mPa s) provides a higher precision in the extrusion process. The physicochemical and biological characterization of the samples demonstrated that the 50/50 scaffolds possessed a resistance to compression comparable to that of native trabecular bone. Moreover, this particular formulation also exhibited a Young's modulus that was higher than that of trabecular bone. Scanning electron microscopy and fluorescence microscopy analysis revealed that osteoblasts were able to adhere, proliferate and also penetrate into the scaffold's architecture. Altogether, our findings suggest that the Fab@home printer can be employed in the manufacture of reproducible scaffolds, using a formulation 50/50 alginate-β-TCP that has suitable properties to be applied as bone substitutes in the future. (paper)

  4. Three-dimensional plotted hydroxyapatite scaffolds with predefined architecture: comparison of stabilization by alginate cross-linking versus sintering.

    Science.gov (United States)

    Kumar, Alok; Akkineni, Ashwini R; Basu, Bikramjit; Gelinsky, Michael

    2016-03-01

    Scaffolds for bone tissue engineering are essentially characterized by porous three-dimensional structures with interconnected pores to facilitate the exchange of nutrients and removal of waste products from cells, thereby promoting cell proliferation in such engineered scaffolds. Although hydroxyapatite is widely being considered for bone tissue engineering applications due to its occurrence in the natural extracellular matrix of this tissue, limited reports are available on additive manufacturing of hydroxyapatite-based materials. In this perspective, hydroxyapatite-based three-dimensional porous scaffolds with two different binders (maltodextrin and sodium alginate) were fabricated using the extrusion method of three-dimensional plotting and the results were compared in reference to the structural properties of scaffolds processed via chemical stabilization and sintering routes, respectively. With the optimal processing conditions regarding to pH and viscosity of binder-loaded hydroxyapatite pastes, scaffolds with parallelepiped porous architecture having up to 74% porosity were fabricated. Interestingly, sintering of the as-plotted hydroxyapatite-sodium alginate (cross-linked with CaCl2 solution) scaffolds led to the formation of chlorapatite (Ca9.54P5.98O23.8Cl1.60(OH)2.74). Both the sintered scaffolds displayed progressive deformation and delayed fracture under compressive loading, with hydroxyapatite-alginate scaffolds exhibiting a higher compressive strength (9.5 ± 0.5 MPa) than hydroxyapatite-maltodextrin scaffolds (7.0 ± 0.6 MPa). The difference in properties is explained in terms of the phase assemblage and microstructure. © The Author(s) 2015.

  5. Attachment, Proliferation, and Morphological Properties of Human Dermal Fibroblasts on Ovine Tendon Collagen Scaffolds: A Comparative Study.

    Science.gov (United States)

    Busra, Fauzi Mh; Lokanathan, Yogeswaran; Nadzir, Masrina Mohd; Saim, Aminuddin; Idrus, Ruszymah Bt Hj; Chowdhury, Shiplu Roy

    2017-03-01

    Collagen type I is widely used as a biomaterial for tissue-engineered substitutes. This study aimed to fabricate different three-dimensional (3D) scaffolds using ovine tendon collagen type I (OTC-I), and compare the attachment, proliferation and morphological features of human dermal fibroblasts (HDF) on the scaffolds. This study was conducted between the years 2014 to 2016 at the Tissue Engineering Centre, UKM Medical Centre. OTC-I was extracted from ovine tendon, and fabricated into 3D scaffolds in the form of sponge, hydrogel and film. A polystyrene surface coated with OTC-I was used as the 2D culture condition. Genipin was used to crosslink the OTC-I. A non-coated polystyrene surface was used as a control. The mechanical strength of OTC-I scaffolds was evaluated. Attachment, proliferation and morphological features of HDF were assessed and compared between conditions. The mechanical strength of OTC-I sponge was significantly higher than that of the other scaffolds. OTC-I scaffolds and the coated surface significantly enhanced HDF attachment and proliferation compared to the control, but no differences were observed between the scaffolds and coated surface. In contrast, the morphological features of HDF including spreading, filopodia, lamellipodia and actin cytoskeletal formation differed between conditions. OTC-I can be moulded into various scaffolds that are biocompatible and thus could be suitable as scaffolds for developing tissue substitutes for clinical applications and in vitro tissue models. However, further study is required to determine the effect of morphological properties on the functional and molecular properties of HDF.

  6. Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching.

    Science.gov (United States)

    Mohanty, Soumyaranjan; Sanger, Kuldeep; Heiskanen, Arto; Trifol, Jon; Szabo, Peter; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2016-04-01

    Limitations in controlling scaffold architecture using traditional fabrication techniques are a problem when constructing engineered tissues/organs. Recently, integration of two pore architectures to generate dual-pore scaffolds with tailored physical properties has attracted wide attention in tissue engineering community. Such scaffolds features primary structured pores which can efficiently enhance nutrient/oxygen supply to the surrounding, in combination with secondary random pores, which give high surface area for cell adhesion and proliferation. Here, we present a new technique to fabricate dual-pore scaffolds for various tissue engineering applications where 3D printing of poly(vinyl alcohol) (PVA) mould is combined with salt leaching process. In this technique the sacrificial PVA mould, determining the structured pore architecture, was filled with salt crystals to define the random pore regions of the scaffold. After crosslinking the casted polymer the combined PVA-salt mould was dissolved in water. The technique has advantages over previously reported ones, such as automated assembly of the sacrificial mould, and precise control over pore architecture/dimensions by 3D printing parameters. In this study, polydimethylsiloxane and biodegradable poly(ϵ-caprolactone) were used for fabrication. However, we show that this technique is also suitable for other biocompatible/biodegradable polymers. Various physical and mechanical properties of the dual-pore scaffolds were compared with control scaffolds with either only structured or only random pores, fabricated using previously reported methods. The fabricated dual-pore scaffolds supported high cell density, due to the random pores, in combination with uniform cell distribution throughout the scaffold, and higher cell proliferation and viability due to efficient nutrient/oxygen transport through the structured pores. In conclusion, the described fabrication technique is rapid, inexpensive, scalable, and compatible

  7. Enrichment of glioma stem cell-like cells on 3D porous scaffolds composed of different extracellular matrix.

    Science.gov (United States)

    Wang, Xuanzhi; Dai, Xingliang; Zhang, Xinzhi; Li, Xinda; Xu, Tao; Lan, Qing

    2018-04-15

    Cancer stem cells (CSCs), being tumor-initiating with self-renewal capacity and heterogeneity, are most likely the cause of tumor resistance, reoccurrence and metastasis. To further investigate the role of CSCs in tumor biology, there is a need to develop an effective culture system to grow, maintain and enrich CSCs. Three-dimensional (3D) cell culture model has been widely used in tumor research and drug screening. Recently, researchers have begun to utilize 3D models to culture cancer cells for CSCs enrichment. In this study, glioma cell line was cultured with 3D porous chitosan (CS) scaffolds or chitosan-hyaluronic acid (CS-HA) scaffolds to explore the possibility of glioma stem cells (GSCs)-like cells enrichment, to study the morphology, gene expression, and in vivo tumorigenicity of 3D scaffolds cells, and to compare results to 2D controls. Results showed that glioma cells on both CS and CS-HA scaffolds could form tumor cell spheroids and increased the expression of GSCs biomarkers compared to conventional 2D monolayers. Furthermore, cells in CS-HA scaffolds had higher expression levels of epithelial-to-mesenchymal transition (EMT)-related gene. Specifically, the in vivo tumorigenicity capability of CS-HA scaffold cultured cells was greater than 2D cells or CS scaffold cultured cells. It is indicated that the chemical composition of scaffold plays an important role in the enrichment of CSCs. Our results suggest that CS-HA scaffolds have a better capability to enrich GSCs-like cells and can serve as a simple and effective way to cultivate and enrich CSCs in vitro to support the study of CSCs biology and development of novel anti-cancer therapies. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Mindfulness-Based Interventions in Counseling

    Science.gov (United States)

    Brown, Amanda P.; Marquis, Andre; Guiffrida, Douglas A.

    2013-01-01

    Mindfulness is a relatively new construct in counseling that is rapidly gaining interest as it is applied to people struggling with a myriad of problems. Research has consistently demonstrated that counseling interventions using mindfulness improve well-being and reduce psychopathology. This article provides a detailed definition of mindfulness,…

  9. Mindfulness: Implications for Substance Abuse and Addiction

    Science.gov (United States)

    Appel, Jonathan; Kim-Appel, Dohee

    2009-01-01

    Mindfulness is a concept that has taken quite a hold on the therapeutic world in recent years. Techniques that induce "mindfulness" are increasingly being employed in Western psychology and psychotherapy to help alleviate a variety of conditions. So while mindfulness has its conceptual roots in Buddhism it has been translated into a Western…

  10. Digital doorway: enriching your mind

    CSIR Research Space (South Africa)

    Cambridge, G

    2008-11-01

    Full Text Available your mind G CAMBRIDGE Meraka Institute, CSIR, PO Box 395, Pretoria, 0001 gcambrid@csir.co.za The Digital Doorway is a joint project between the South African Department of Science and Technology (DST) and the Meraka Institute of the CSIR...

  11. Mind, matter, and quantum mechanics

    International Nuclear Information System (INIS)

    Stapp, H.P.

    1982-01-01

    A theory of psychophysical phenomena is proposed. It resolves simultaneously four basic problems of science, namely the problems of the connections between: (1) mind and matter, (2), quantum theory and reality, (3) relativity theory and ''becoming,'' and (4) relativity theory and Bell's theorem

  12. Mindfulness på arbejde

    DEFF Research Database (Denmark)

    Svalgaard, Lotte

    2011-01-01

    organisationer, hvor fokus er på følelser, kultur, mindfulness, negativ formåen og mobning. •Ledelse, hvor postmoderne ledelsesmetoder bringes frem, beskrives og analyseres i forhold til selvstyrende grupper, mentalisering, teamorienteret ledelse og kønsperspektivet på ledelse. •Konsulentperspektivet, som...

  13. Keeping Things Mindfully on Track

    DEFF Research Database (Denmark)

    Hernes, Tor; Irgens, Eirik J.

    2013-01-01

    an investment of effort, mindfulness and preparedness for change, even if no perceptible change occurs. Although the organizational literature has to some extent dealt with learning under continuity, putting it more firmly on the organizational learning agenda is necessary. A central element of a more explicit...

  14. Digitalization of the human mind

    Directory of Open Access Journals (Sweden)

    Mr.Sc. Drita Mehmeti

    2013-06-01

    Full Text Available The human faces with various problems already in its first steps in live, and carriers of such life situations are found in various ages which bring new currents in the way of life. Starting from the ancient Greek thought, the human and its mind made the centre of the world, already orienting the Western thought towards the study of the human mind (namely human reason, since it made the key tool for human survival. Although human problems have been discussed throughout various ages, they have not been able to resolve in full the human problems, and therefore, the same issues were taken by the representatives of the socalled “critical theory”, who used the theory to criticize the way of live Western civilization was offering, known as digitalization of the human mind. The human problems are addressed in a poly-dimensional manner. The factors affecting the human mind are: industrial civilization, technical progress, automation, overtly influence of machinery on humans, substitution of cultural values, which in sum have developed a new World Order, where the ruler is technology. In the modern world, the human fails to recognize himself, since he is out of himself and lives according to the rules set forth by the “remote control”. In the flow of this kind of livelihood, human alienates, or in other words, the human goes out of himself, trying to adapt maximally to the requirements of the new way of life.

  15. A Double-Minded Fractal

    Science.gov (United States)

    Simoson, Andrew J.

    2009-01-01

    This article presents a fun activity of generating a double-minded fractal image for a linear algebra class once the idea of rotation and scaling matrices are introduced. In particular the fractal flip-flops between two words, depending on the level at which the image is viewed. (Contains 5 figures.)

  16. Opening Doors, Hearts and Minds

    Science.gov (United States)

    Foster, Andrea

    2007-01-01

    A panel discussion, "Opening Doors, Hearts and Minds," was hosted at the 2006 annual COEO conference. Four dedicated Torontonians shared how they interpret outdoor environmental education and environmental education in what they do and offered suggestions as to how their work might be integrated in diverse urban communities. Tafari…

  17. Emotions, narratives, and ethical mindfulness.

    Science.gov (United States)

    Guillemin, Marilys; Gillam, Lynn

    2015-06-01

    Clinical care is laden with emotions, from the perspectives of both clinicians and patients. It is important that emotions are addressed in health professions curricula to ensure that clinicians are humane healers as well as technical experts. Emotions have a valuable and generative role in health professional ethics education.The authors have previously described a narrative ethics pedagogy, the aim of which is to develop ethical mindfulness. Ethical mindfulness is a state of being that acknowledges everyday ethics and ethically important moments as significant in clinical care, with the aim of enabling ethical clinical practice. Using a sample narrative, the authors extend this concept to examine five features of ethical mindfulness as they relate to emotions: (1) being sensitized to emotions in everyday practice, (2) acknowledging and understanding the ways in which emotions are significant in practice, (3) being able to articulate the emotions at play during ethically important moments, (4) being reflexive and acknowledging both the generative aspects and the limitations of emotions, and (5) being courageous.The process of writing and engaging with narratives can lead to ethical mindfulness, including the capacity to understand and work with emotions. Strategies for productively incorporating emotions in narrative ethics teaching are described. This can be a challenging domain within medical education for both educators and health care students and thus needs to be addressed sensitively and responsibly. The potential benefit of educating health professionals in a way which addresses emotionality in an ethical framework makes the challenges worthwhile.

  18. Explaining the Mind: Problems, Problems

    OpenAIRE

    Harnad, Stevan

    2001-01-01

    The mind/body problem is the feeling/function problem: How and why do feeling systems feel? The problem is not just "hard" but insoluble (unless one is ready to resort to telekinetic dualism). Fortunately, the "easy" problems of cognitive science (such as the how and why of categorization and language) are not insoluble. Five books (by Damasio, Edelman/Tononi...

  19. Quechua Children's Theory of Mind.

    Science.gov (United States)

    McCormick, Penelope G.; Olson, David R.

    Three different theory of mind tasks were conducted with 4- to 8-year-old Quechua peasant children in the Peruvian Andes. The study investigated the ways in which children in preliterate cultures think and the possibility that they think differently than children in literate cultures. The tasks included: (1) a false-belief task, which tested the…

  20. Brain Friendly Techniques: Mind Mapping

    Science.gov (United States)

    Goldberg, Cristine

    2004-01-01

    Mind Mapping can be called the Swiss Army Knife for the brain, a total visual thinking tool or a multi-handed thought catcher. Invented by Tony Buzan in the early 1970s and used by millions around the world, it is a method that can be a part of a techniques repertoire when teaching information literacy, planning, presenting, thinking, and so…

  1. The effect of 3D nanofibrous scaffolds on the chondrogenesis of induced pluripotent stem cells and their application in restoration of cartilage defects.

    Science.gov (United States)

    Liu, Ji; Nie, Huarong; Xu, Zhengliang; Niu, Xin; Guo, Shangchun; Yin, Junhui; Guo, Fei; Li, Gang; Wang, Yang; Zhang, Changqing

    2014-01-01

    The discovery of induced pluripotent stem cells (iPSCs) rendered the reprogramming of terminally differentiated cells to primary stem cells with pluripotency possible and provided potential for the regeneration and restoration of cartilage defect. Chondrogenic differentiation of iPSCs is crucial for their application in cartilage tissue engineering. In this study we investigated the effect of 3D nanofibrous scaffolds on the chondrogenesis of iPSCs and articular cartilage defect restoration. Super-hydrophilic and durable mechanic polycaprolactone (PCL)/gelatin scaffolds were fabricated using two separate electrospinning processes. The morphological structure and mechanical properties of the scaffolds were characterized. The chondrogenesis of the iPSCs in vitro and the restoration of the cartilage defect was investigated using scanning electron microscopy (SEM), the Cell Counting Kit-8 (CCK-8), histological observation, RT-qPCR, and western blot analysis. iPSCs on the scaffolds expressed higher levels of chondrogenic markers than the control group. In an animal model, cartilage defects implanted with the scaffold-cell complex exhibited an enhanced gross appearance and histological improvements, higher cartilage-specific gene expression and protein levels, as well as subchondral bone regeneration. Therefore, we showed scaffolds with a 3D nanofibrous structure enhanced the chondrogenesis of iPSCs and that iPSC-containing scaffolds improved the restoration of cartilage defects to a greater degree than did scaffolds alone in vivo.

  2. The effect of 3D nanofibrous scaffolds on the chondrogenesis of induced pluripotent stem cells and their application in restoration of cartilage defects.

    Directory of Open Access Journals (Sweden)

    Ji Liu

    Full Text Available The discovery of induced pluripotent stem cells (iPSCs rendered the reprogramming of terminally differentiated cells to primary stem cells with pluripotency possible and provided potential for the regeneration and restoration of cartilage defect. Chondrogenic differentiation of iPSCs is crucial for their application in cartilage tissue engineering. In this study we investigated the effect of 3D nanofibrous scaffolds on the chondrogenesis of iPSCs and articular cartilage defect restoration. Super-hydrophilic and durable mechanic polycaprolactone (PCL/gelatin scaffolds were fabricated using two separate electrospinning processes. The morphological structure and mechanical properties of the scaffolds were characterized. The chondrogenesis of the iPSCs in vitro and the restoration of the cartilage defect was investigated using scanning electron microscopy (SEM, the Cell Counting Kit-8 (CCK-8, histological observation, RT-qPCR, and western blot analysis. iPSCs on the scaffolds expressed higher levels of chondrogenic markers than the control group. In an animal model, cartilage defects implanted with the scaffold-cell complex exhibited an enhanced gross appearance and histological improvements, higher cartilage-specific gene expression and protein levels, as well as subchondral bone regeneration. Therefore, we showed scaffolds with a 3D nanofibrous structure enhanced the chondrogenesis of iPSCs and that iPSC-containing scaffolds improved the restoration of cartilage defects to a greater degree than did scaffolds alone in vivo.

  3. Minding the Gap: Comics as Scaffolding for Critical Literacy Skills in the Classroom

    Science.gov (United States)

    Vie, Stephanie; Dieterle, Brandy

    2016-01-01

    Comics--both digital and print--increasingly make their way to the classroom. Scholars in the field have illustrated the pedagogical value of comics, but there remains little discussion as of yet about how comics can inform critical literacy, a necessary skill for twenty-first-century communication. Here the authors discuss an approach to…

  4. Bone Regeneration of Hydroxyapatite with Granular Form or Porous Scaffold in Canine Alveolar Sockets

    Science.gov (United States)

    JANG, SEOK JIN; KIM, SE EUN; HAN, TAE SUNG; SON, JUN SIK; KANG, SEONG SOO; CHOI, SEOK HWA

    2017-01-01

    This study was undertaken to assess bone regeneration using hydroxyapatite (HA). The primary focus was comparison of bone regeneration between granular HA (gHA) forms and porous HA (pHA) scaffold. The extracted canine alveolar sockets were divided with three groups: control, gHA and pHA. Osteogenic effect in the gHA and pHA groups showed bone-specific surface and bone mineral density to be significantly higher than that of the control group (psocket healing. For new bone formation during 8 weeks' post-implantation, HA with porous scaffold was superior to the granular form of HA. PMID:28438860

  5. Computational design of new molecular scaffolds for medicinal chemistry, part II: generalization of analog series-based scaffolds

    Science.gov (United States)

    Dimova, Dilyana; Stumpfe, Dagmar; Bajorath, Jürgen

    2018-01-01

    Aim: Extending and generalizing the computational concept of analog series-based (ASB) scaffolds. Materials & methods: Methodological modifications were introduced to further increase the coverage of analog series (ASs) and compounds by ASB scaffolds. From bioactive compounds, ASs were systematically extracted and second-generation ASB scaffolds isolated. Results: More than 20,000 second-generation ASB scaffolds with single or multiple substitution sites were extracted from active compounds, achieving more than 90% coverage of ASs. Conclusion: Generalization of the ASB scaffold approach has yielded a large knowledge base of scaffold-capturing compound series and target information. PMID:29379641

  6. Composite PLA/PEG/nHA/Dexamethasone Scaffold Prepared by 3D Printing for Bone Regeneration.

    Science.gov (United States)

    Li, Xiaoyuan; Wang, Yu; Wang, Zigui; Qi, Yanxin; Li, Linlong; Zhang, Peibiao; Chen, Xuesi; Huang, Yubin

    2018-04-24

    3D printing has become an essential part of bone tissue engineering and attracts great attention for the fabrication of bioactive scaffolds. Combining this rapid manufacturing technique with chemical precipitation, biodegradable 3D scaffold composed of polymer matrix (polylactic acid and polyethylene glycol), ceramics (nano hydroxyapatite), and drugs (dexamethasone (Dex)) is prepared. Results of water contact angle, differential scanning calorimeter, and mechanical tests confirm that incorporation of Dex leads to significantly improved wettability, higher crystallinity degree, and tunable degradation rates. In vitro experiment with mouse MC3T3-E1 cells implies that Dex released from scaffolds is not beneficial for early cell proliferation, but it improves late alkaline phosphatase secretion and mineralization significantly. Anti-inflammation assay of murine RAW 264.7 cells proves that Dex released from all the scaffolds successfully suppresses lipopolysaccharide induced interleukin-6 and inducible nitric oxide synthase secretion by M1 macrophages. Further in vivo experiment on rat calvarial defects indicates that scaffolds containing Dex promote osteoinduction and osteogenic response and would be promising candidates for clinical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Role of Demyelination Efficiency within Acellular Nerve Scaffolds during Nerve Regeneration across Peripheral Defects

    Directory of Open Access Journals (Sweden)

    Meiqin Cai

    2017-01-01

    Full Text Available Hudson’s optimized chemical processing method is the most commonly used chemical method to prepare acellular nerve scaffolds for the reconstruction of large peripheral nerve defects. However, residual myelin attached to the basal laminar tube has been observed in acellular nerve scaffolds prepared using Hudson’s method. Here, we describe a novel method of producing acellular nerve scaffolds that eliminates residual myelin more effectively than Hudson’s method through the use of various detergent combinations of sulfobetaine-10, sulfobetaine-16, Triton X-200, sodium deoxycholate, and peracetic acid. In addition, the efficacy of this new scaffold in repairing a 1.5 cm defect in the sciatic nerve of rats was examined. The modified method produced a higher degree of demyelination than Hudson’s method, resulting in a minor host immune response in vivo and providing an improved environment for nerve regeneration and, consequently, better functional recovery. A morphological study showed that the number of regenerated axons in the modified group and Hudson group did not differ. However, the autograft and modified groups were more similar in myelin sheath regeneration than the autograft and Hudson groups. These results suggest that the modified method for producing a demyelinated acellular scaffold may aid functional recovery in general after nerve defects.

  8. Analysis Critical Thinking Stage of Eighth Grade in PBL-Scaffolding Setting To Solve Mathematical Problems

    Directory of Open Access Journals (Sweden)

    Nur Aisyah Isti

    2017-03-01

    Full Text Available The purpose of this research was described critical thinking stage of students grade VIII in setting PBL and scaffolding to solve mathematics problems. Critical thinking stage consists of clarification, assesment, inference, and strategy/tactics. The subject were teo students in the level of capacity to think critical (uncritical, less critical, quite critical, and critical. So that this research subject was 8 students in VIII A One State Junior High School of Temanggung. The result showed a description (1 critical thinking stage of students in setting PBL, in clarification the higher level of capacity to think critical students, students can identification information from question fully, can identificatio problem became detailed, and can explored the relationship among the information; (2 a strategy of scaffolding were given by critical thinking stage and TKBK, in assesment, scaffolding had given was given hint/key classically; and (3 transformation characteristic of the critical thinking stage of students after given scaffolding, it because of habituation in setting PBL and scaffolding.

  9. Mechanical properties and biocompatibility of porous titanium scaffolds for bone tissue engineering.

    Science.gov (United States)

    Chen, Yunhui; Frith, Jessica Ellen; Dehghan-Manshadi, Ali; Attar, Hooyar; Kent, Damon; Soro, Nicolas Dominique Mathieu; Bermingham, Michael J; Dargusch, Matthew S

    2017-11-01

    Synthetic scaffolds are a highly promising new approach to replace both autografts and allografts to repair and remodel damaged bone tissue. Biocompatible porous titanium scaffold was manufactured through a powder metallurgy approach. Magnesium powder was used as space holder material which was compacted with titanium powder and removed during sintering. Evaluation of the porosity and mechanical properties showed a high level of compatibility with human cortical bone. Interconnectivity between pores is higher than 95% for porosity as low as 30%. The elastic moduli are 44.2GPa, 24.7GPa and 15.4GPa for 30%, 40% and 50% porosity samples which match well to that of natural bone (4-30GPa). The yield strengths for 30% and 40% porosity samples of 221.7MPa and 117MPa are superior to that of human cortical bone (130-180MPa). In-vitro cell culture tests on the scaffold samples using Human Mesenchymal Stem Cells (hMSCs) demonstrated their biocompatibility and indicated osseointegration potential. The scaffolds allowed cells to adhere and spread both on the surface and inside the pore structures. With increasing levels of porosity/interconnectivity, improved cell proliferation is obtained within the pores. It is concluded that samples with 30% porosity exhibit the best biocompatibility. The results suggest that porous titanium scaffolds generated using this manufacturing route have excellent potential for hard tissue engineering applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. In vivo cyclic loading as a potent stimulatory signal for bone formation inside tissue engineering scaffold

    Directory of Open Access Journals (Sweden)

    A Roshan-Ghias

    2010-02-01

    Full Text Available In clinical situations, bone defects are often located at load bearing sites. Tissue engineering scaffolds are future bone substitutes and hence they will be subjected to mechanical stimulation. The goal of this study was to test if cyclic loading can be used as stimulatory signal for bone formation in a bone scaffold. Poly(L-lactic acid (PLA/ 5% beta-tricalcium phosphate (beta-TCP scaffolds were implanted in both distal femoral epiphyses of eight rats. Right knees were stimulated (10N, 4Hz, 5 min five times, every two days, starting from the third day after surgery while left knees served as control. Finite element study of the in vivo model showed that the strain applied to the scaffold is similar to physiological strains. Using micro-computed tomography (CT, all knees were scanned five times after the surgery and the related bone parameters of the newly formed bone were quantified. Statistical modeling was used to estimate the evolution of these parameters as a function of time and loading. The results showed that mechanical stimulation had two effects on bone volume (BV: an initial decrease in BV at week 2, and a long-term increase in the rate of bone formation by 28%. At week 13, the BV was then significantly higher in the loaded scaffolds.

  11. Scaffolding for motivation by parents, and child homework motivations and emotions: Effects of a training programme.

    Science.gov (United States)

    Moè, Angelica; Katz, Idit; Alesi, Marianna

    2018-06-01

    Based on the principles of scaffolding for motivation and on the assumptions of self-determination theory, two studies aimed to assess the role played by perceived parental autonomy-supportive scaffolding on child homework autonomous motivation, self-efficacy, affect, and engagement. The results of Study 1, which involved 122 parents and their children, showed that the higher the parental autonomous motivation, the more their children perceived them as autonomy-supportive while scaffolding for motivation, and hence developed autonomous motivation, self-efficacy, and engagement in homework. In Study 2, 37 parents were involved in a four-session training programme that focused on sustaining autonomy-supportive scaffolding modalities. The training decreased parental negative affect, prevented child negative affect increase, and maintained child homework motivation. The discussion focuses on the strength that parents have with regard to helping their children develop less negative, and potentially also more positive attitude towards homework, through autonomy support as a scaffold for motivation. © 2018 The British Psychological Society.

  12. Morphology and characterization of 3D micro-porous structured chitosan scaffolds for tissue engineering.

    Science.gov (United States)

    Hsieh, Wen-Chuan; Chang, Chih-Pong; Lin, Shang-Ming

    2007-06-15

    This research studies the morphology and characterization of three-dimensional (3D) micro-porous structures produced from biodegradable chitosan for use as scaffolds for cells culture. The chitosan 3D micro-porous structures were produced by a simple liquid hardening method, which includes the processes of foaming by mechanical stirring without any chemical foaming agent added, and hardening by NaOH cross linking. The pore size and porosity were controlled with mechanical stirring strength. This study includes the morphology of chitosan scaffolds, the characterization of mechanical properties, water absorption properties and in vitro enzymatic degradation of the 3D micro-porous structures. The results show that chitosan 3D micro-porous structures were successfully produced. Better formation samples were obtained when chitosan concentration is at 1-3%, and concentration of NaOH is at 5%. Faster stirring rate would produce samples of smaller pore diameter, but when rotation speed reaches 4000 rpm and higher the changes in pore size is minimal. Water absorption would reduce along with the decrease of chitosan scaffolds' pore diameter. From stress-strain analysis, chitosan scaffolds' mechanical properties are improved when it has smaller pore diameter. From in vitro enzymatic degradation results, it shows that the disintegration rate of chitosan scaffolds would increase along with the processing time increase, but approaching equilibrium when the disintegration rate reaches about 20%.

  13. 3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro

    International Nuclear Information System (INIS)

    Scaffaro, Roberto; Lo Re, Giada; Rigogliuso, Salvatrice; Ghersi, Giulio

    2012-01-01

    We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-based blends, on the simultaneous bulk/surface modifications and pore architectures in the scaffolds, and assessed the effects on human hepatocarcinoma viability and cell adhesion. The influence of PEG molecular weight on the scaffold morphology and cell viability and adhesion were also investigated. Morphological studies indicated that it was possible to obtain scaffolds with well-interconnected pores of assorted sizes. The analysis confirmed that SK-Hep1 cells adhered well to the polymeric support and emitted surface protrusions necessary to grow and differentiate three-dimensional systems. PEGs with higher molecular weight showed the best results in terms of cell adhesion and viability. (paper)

  14. 3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro

    Science.gov (United States)

    Scaffaro, Roberto; Lo Re, Giada; Rigogliuso, Salvatrice; Ghersi, Giulio

    2012-08-01

    We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-based blends, on the simultaneous bulk/surface modifications and pore architectures in the scaffolds, and assessed the effects on human hepatocarcinoma viability and cell adhesion. The influence of PEG molecular weight on the scaffold morphology and cell viability and adhesion were also investigated. Morphological studies indicated that it was possible to obtain scaffolds with well-interconnected pores of assorted sizes. The analysis confirmed that SK-Hep1 cells adhered well to the polymeric support and emitted surface protrusions necessary to grow and differentiate three-dimensional systems. PEGs with higher molecular weight showed the best results in terms of cell adhesion and viability.

  15. Improving Students' Speaking Ability through Scaffolding Technique

    Directory of Open Access Journals (Sweden)

    Gede Ginaya

    2018-03-01

    Full Text Available Students often got confused and felt hesitant when they speak English. This situation had caused poor speaking ability, which then lead to serious problem in the teaching-learning process.  The application of scaffolding technique in the EFL learning might be the ideal solution; it had some principles that could improve the students’ speaking ability. This research is aimed at finding out the effect of the implementing Scaffolding Technique towards the students’ speaking ability. Participants were 50 (27 males and 23 females third-semester students, enrolled in a three-year diploma program in Travel and Tourism Business, State Polytechnic of Bali in 2017/2018 academic year. The students in the experimental group were given communicative activities such as brainstorming, business games, simulation, WebQuest, problem-solving, which were carefully designed to necessitate the implementation of the scaffolding technique. The students in the control group were taught by the deductive method of the lesson book. The students’ performance in the post-test was compared for both groups in order to determine whether there were significant differences between the groups in relation to the treatment. Significant differences occurring in the experimental group’s post-test speaking performance when compared to the pre-test indicate that the implementation of scaffolding technique can improve students’ speaking ability. The result of this study indicates scaffolding technique has the potential for use in promoting students’ speaking ability

  16. Heterogeneity of Scaffold Biomaterials in Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Lauren Edgar

    2016-05-01

    Full Text Available Tissue engineering (TE offers a potential solution for the shortage of transplantable organs and the need for novel methods of tissue repair. Methods of TE have advanced significantly in recent years, but there are challenges to using engineered tissues and organs including but not limited to: biocompatibility, immunogenicity, biodegradation, and toxicity. Analysis of biomaterials used as scaffolds may, however, elucidate how TE can be enhanced. Ideally, biomaterials should closely mimic the characteristics of desired organ, their function and their in vivo environments. A review of biomaterials used in TE highlighted natural polymers, synthetic polymers, and decellularized organs as sources of scaffolding. Studies of discarded organs supported that decellularization offers a remedy to reducing waste of donor organs, but does not yet provide an effective solution to organ demand because it has shown varied success in vivo depending on organ complexity and physiological requirements. Review of polymer-based scaffolds revealed that a composite scaffold formed by copolymerization is more effective than single polymer scaffolds because it allows copolymers to offset disadvantages a single polymer may possess. Selection of biomaterials for use in TE is essential for transplant success. There is not, however, a singular biomaterial that is universally optimal.

  17. Scaffolds in regenerative endodontics: A review

    Science.gov (United States)

    Gathani, Kinjal M.; Raghavendra, Srinidhi Surya

    2016-01-01

    Root canal therapy has enabled us to save numerous teeth over the years. The most desired outcome of endodontic treatment would be when diseased or nonvital pulp is replaced with healthy pulp tissue that would revitalize the teeth through regenerative endodontics. ‘A search was conducted using the Pubmed and MEDLINE databases for articles with the criteria ‘Platelet rich plasma’, ‘Platelet rich fibrin’, ‘Stem cells’, ‘Natural and artificial scaffolds’ from 1982–2015’. Tissues are organized as three-dimensional structures, and appropriate scaffolding is necessary to provide a spatially correct position of cell location and regulate differentiation, proliferation, or metabolism of the stem cells. Extracellular matrix molecules control the differentiation of stem cells, and an appropriate scaffold might selectively bind and localize cells, contain growth factors, and undergo biodegradation over time. Different scaffolds facilitate the regeneration of different tissues. To ensure a successful regenerative procedure, it is essential to have a thorough and precise knowledge about the suitable scaffold for the required tissue. This article gives a review on the different scaffolds providing an insight into the new developmental approaches on the horizon. PMID:27857762

  18. Scaffolds in regenerative endodontics: A review

    Directory of Open Access Journals (Sweden)

    Kinjal M Gathani

    2016-01-01

    Full Text Available Root canal therapy has enabled us to save numerous teeth over the years. The most desired outcome of endodontic treatment would be when diseased or nonvital pulp is replaced with healthy pulp tissue that would revitalize the teeth through regenerative endodontics. ′A search was conducted using the Pubmed and MEDLINE databases for articles with the criteria ′Platelet rich plasma′, ′Platelet rich fibrin′, ′Stem cells′, ′Natural and artificial scaffolds′ from 1982-2015′. Tissues are organized as three-dimensional structures, and appropriate scaffolding is necessary to provide a spatially correct position of cell location and regulate differentiation, proliferation, or metabolism of the stem cells. Extracellular matrix molecules control the differentiation of stem cells, and an appropriate scaffold might selectively bind and localize cells, contain growth factors, and undergo biodegradation over time. Different scaffolds facilitate the regeneration of different tissues. To ensure a successful regenerative procedure, it is essential to have a thorough and precise knowledge about the suitable scaffold for the required tissue. This article gives a review on the different scaffolds providing an insight into the new developmental approaches on the horizon.

  19. In vitro osteoclastogenesis on textile chitosan scaffold

    Directory of Open Access Journals (Sweden)

    C Heinemann

    2010-02-01

    Full Text Available Textile chitosan fibre scaffolds were evaluated in terms of interaction with osteoclast-like cells, derived from human primary monocytes. Part of the scaffolds was further modified by coating with fibrillar collagen type I in order to make the surface biocompatible. Monocytes were cultured directly on the scaffolds in the presence of macrophage colony stimulating factor (M-CSF and receptor activator of nuclear factor kappaB ligand (RANKL for up to 18 days. Confocal laser scanning microscopy (CLSM as well as scanning electron microscopy (SEM revealed the formation of multinuclear osteoclast-like cells on both the raw chitosan fibres and the collagen-coated scaffolds. The modified surface supported the osteoclastogenesis. Differentiation towards the osteoclastic lineage was confirmed by the microscopic detection of cathepsin K, tartrate resistant acid phosphatase (TRAP, acidic compartments using 3-(2,4-dinitroanillino-3’-amino-N-methyldipropylamine (DAMP, immunological detection of TRAP isoform 5b, and analysis of gene expression of the osteoclastic markers TRAP, cathepsin K, vitronectin receptor, and calcitonin receptor using reverse transcription-polymerase chain reaction (RT-PCR. The feature of the collagen-coated but also of the raw chitosan fibre scaffolds to support attachment and differentiation of human monocytes facilitates cell-induced material resorption – one main requirement for successful bone tissue engineering.

  20. ALP gene expression in cDNA samples from bone tissue engineering using a HA/TCP/Chitosan scaffold

    Science.gov (United States)

    Stephanie, N.; Katarina, H.; Amir, L. R.; Gunawan, H. A.

    2017-08-01

    This study examined the potential use of hydroxyapatite (HA)/tricalcium phosphate (TCP)/Chitosan as a bone tissue engineering scaffold. The potential for using HA/TCP/chitosan as a scaffold was analyzed by measuring expression of the ALP osteogenic gene in cDNA from bone biopsies from four Macaque nemestrina. Experimental conditions included control (untreated), treatment with HA/TCP 70:30, HA/TCP 50:50, and HA/TCP/chitosan. cDNA samples were measured quantitively with Real-Time PCR (qPCR) and semi-quantitively by gel electrophoresis. There were no significant differences in ALP gene expression between treatment subjects after two weeks, but the HA/TCP/chitosan treatment gave the highest level of expression after four weeks. The scaffold using the HA/TCP/chitosan combination induced a higher level of expression of the osteogenic gene ALP than did scaffold without chitosan.

  1. Impact of Particle Size of Ceramic Granule Blends on Mechanical Strength and Porosity of 3D Printed Scaffolds

    Directory of Open Access Journals (Sweden)

    Sebastian Spath

    2015-07-01

    Full Text Available 3D printing is a promising method for the fabrication of scaffolds in the field of bone tissue engineering. To date, the mechanical strength of 3D printed ceramic scaffolds is not sufficient for a variety of applications in the reconstructive surgery. Mechanical strength is directly in relation with the porosity of the 3D printed scaffolds. The porosity is directly influenced by particle size and particle-size distribution of the raw material. To investigate this impact, a hydroxyapatite granule blend with a wide particle size distribution was fractioned by sieving. The specific fractions and bimodal mixtures of the sieved granule blend were used to 3D print specimens. It has been shown that an optimized arrangement of fractions with large and small particles can provide 3D printed specimens with good mechanical strength due to a higher packing density. An increase of mechanical strength can possibly expand the application area of 3D printed hydroxyapatite scaffolds.

  2. Biocomposite scaffolds for bone regeneration: Role of chitosan and hydroxyapatite within poly-3-hydroxybutyrate-co-3-hydroxyvalerate on mechanical properties and in vitro evaluation.

    Science.gov (United States)

    Zhang, Sai; Prabhakaran, Molamma P; Qin, Xiaohong; Ramakrishna, Seeram

    2015-11-01

    Bio-engineered scaffolds for bone tissue regeneration is an exploding area of research mainly because they can satisfy the essential demands and current challenges in bone replacement therapies, by imitating the extracellular matrix (ECM) of the native bone. We fabricated bio-composite nanofibrous scaffolds with a blend of poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), chitosan (CTS) and hydroxyapatite (HA) during this study. Morphological evaluation confirmed the fiber diameters of PHBV, PHBV/CTS (90:10), PHBV/CTS/HA4 (85.5:9.5:5) and PHBV/CTS/HA8 (81:9:10) as 405 ± 74 nm, 334 ± 82 nm, 316 ± 103 nm and 256 ± 110 nm, respectively. The PHBV/CTS/HA4 and PHBV/CTS/HA8 scaffolds were capable of enduring the long term culture of human fetal osteoblasts (hFOB) with ultimate tensile strength of 3.55 ± 0.22 MPa and 4.19 ± 0.19 MPa, respectively. The proliferation of osteoblasts on PHBV/CTS/HA8 scaffold was found 34.10% higher than that on PHBV scaffold on day 20. Cell maturation identified by alkaline phosphatase activity on day 20 was significantly higher on PHBV/CTS/HA8 scaffold than that on PHBV scaffold. The cells on PHBV/CTS/HA8 scaffold also acquired higher mineral deposition (25.79%) than the mineral deposition on PHBV scaffold by day 20, confirmed by EDX analysis. Based on the results, we concluded that the electrospun PHBV/CTS/HA8 scaffolds hold great potential to promote the regeneration of bone tissue due to the synergistic effect of chitosan and HA, whereby chitosan provided cell recognition sites while HA acted as a chelating agent for organizing the apatite-like mineralization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Perceived stress, depressive symptoms, and suicidal ideation in undergraduate women with varying levels of mindfulness.

    Science.gov (United States)

    Anastasiades, Maria H; Kapoor, Shweta; Wootten, Jennifer; Lamis, Dorian A

    2017-02-01

    Research has demonstrated that perceived stress and depression are risk factors for suicidal ideation in young adults, particularly women attending college. Female undergraduate students (N = 928) were administered measures assessing their levels of stress, depressive symptoms, suicidal thoughts, and mindfulness. A moderated-mediation analysis was conducted to examine the complex associations among these variables. Results indicated that mindfulness moderated the mediated effect of depressive symptoms on perceived stress and suicidal ideation. Specifically, the indirect effect was stronger in college women with lower levels of mindfulness as compared to those students who reported higher mindfulness. Thus, teaching mindfulness techniques on college campuses may be an important strategy for preventing suicide, especially among young adult women experiencing stress and depressive symptoms.

  4. Mindfulness and its relationship with eating disorders symptomatology in women receiving residential treatment.

    Science.gov (United States)

    Butryn, Meghan L; Juarascio, Adrienne; Shaw, Jena; Kerrigan, Stephanie G; Clark, Vicki; O'Planick, Antonia; Forman, Evan M

    2013-01-01

    Mindfulness and its related constructs (e.g., awareness and acceptance) are increasingly being recognized as relevant to understanding eating disorders and improving treatment. The purpose of this study was to (1) examine the relationship between mindfulness and ED symptomatology at baseline and (2) examine how changes in mindfulness relate to change in ED symptomatology. Measures of mindfulness and ED symptomatology were administered to 88 patients upon admission to residential ED treatment and at discharge. Baseline ED symptomatology was associated with lower awareness, acceptance, and cognitive defusion, and higher emotional avoidance. Improvements in these variables were related to improvement in ED symptomatology. Interventions targeting mindfulness could be beneficial for patients with EDs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Comparison of the components of mindfulness on Stimulant and opiate addicts

    Directory of Open Access Journals (Sweden)

    Sayeadyounes Mohammadi

    2016-07-01

    Full Text Available Background: Phenomenon of addiction as one of the social problem have the high prevalence, especially among youth. Study and scientific cognition of mental and psychological components of addicts is very important in order to help them to compatibility and reduce their psychological problem. Therefore, the aim of present study was to comparison of mindfulness components on stimulant and opiate addicts. Materials & Methods: In this study 60 addicts (30 opiate addicts and 30 stimulants addicts were studied by using Five Factor Mindfulness Questionnaire (FFMQ. Data were analyzed by using multivariate analysis of variance (MANOVA. Results: findings showed that there was a significant difference between opiate and stimulant addicts in mindfulness components. Conclusion: results illustrated that the opiate addicts gained higher scores than stimulant addicts in mindfulness components. The results also emphasized that mindfulness components are as determinant variable in opiate and stimulant addicts pathology.

  6. Graphene-containing PCL- coated Porous 13-93B3 Bioactive Glass Scaffolds for Bone Regeneration

    Science.gov (United States)

    Türk, Mert; Deliormanlı, Aylin M.

    2018-04-01

    Borate-based 13-93B3 bioactive glass scaffolds were coated with the graphene-containing poly-caprolactone (PCL) solution to prepare electrically conductive composites for biomedical applications. Results revealed that electrical conductivity of the scaffolds increased with increasing concentration of graphene nanoparticles. Significant difference was not observed in hydroxyapatite forming ability of the bare and the graphene-containing scaffolds immersed in simulated body fluid. In vitro cytotoxicity experiments (XTT tests) showed that pre-osteoblastic MC3T3-E1 cell viability percentages of the graphene- containing samples was higher than control group samples after 7 days of incubation. However, a decrease in cell viability rates was obtained after 14 days of incubation for samples coated with PCL containing graphene starting from 3 wt%. Additionally, results obtained in the live-dead assay were consistent with the results of XTT tests. A higher ALP activity was detected in cells cultured on the graphene-containing borate glass scaffolds than those on the bare PCL coated 13-93B3 scaffolds suggesting the presence of graphene nanopowders stimulated an early stage of osteoblastic differentiation. SEM analysis showed that MC3T3-E1 cells exhibited a flat appearance and spread out through the surface in all groups of scaffolds starting from 3 days of incubation.

  7. Schooled in Our Own Minds: Mind-Wandering and Mindfulness in the Makings of the Curriculum

    Science.gov (United States)

    Ergas, Oren

    2018-01-01

    Curriculum discourse focuses understandably, on the formal and enacted curriculum; however, studies demonstrate that much of individuals' waking hours are spent in task-unrelated thinking and mind-wandering. No less, this pervasive phenomenon has been shown to affect us in many ways that can be linked to education. This paper examines this…

  8. Experiencing mindfulness meditation - a client narrative perspective

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    2009-01-01

    The study was based on the non-participant involvement of the researcher in four six-to-eight weeks' mindfulness meditation training courses led by chartered psychologists. The participants suffered from stress/sleeplessness, depression or agoraphobia in the presented cases. They were selected...... and practicing mindfulness meditation. It is not the intention to give evidence about the effectiveness of mindfulness meditation in general, but to present the whats and hows of cases where mindfulness meditation appears to improve quality of life, health and well-being. Keywords: Mindfulness meditation...

  9. Hearts and minds

    DEFF Research Database (Denmark)

    Gauthier, Claudine Joëlle; Lefort, Muriel; Mekary, Saïd

    2015-01-01

    of disease was investigated within 2 groups of healthy younger and older adults. Age-related changes in executive function, elasticity of the aortic arch, cardiorespiratory fitness, and cerebrovascular reactivity were quantified, as well as the association between these parameters within the older group...... velocity; p = 0.046) and higher cardiorespiratory fitness (VO2 max; p = 0.036). Furthermore, VO2 max was found to be negatively associated with blood oxygenation level dependent cerebrovascular reactivity to CO2 in frontal regions involved in the task (p = 0.038) but positively associated...

  10. A Guide to Scaffold Use in the Construction Industry

    National Research Council Canada - National Science Library

    2001-01-01

    On August 30, 1996, OSHA issued revised standards for scaffolds. The revised standard, known as "Safety Standards for Scaffolds Used in the Construction Industry" is found in Title 29 Code of Federal Regulations (CFR) Part, Subpart L...

  11. Biodegradation and bioresorption of poly(-caprolactone) nanocomposite scaffolds

    CSIR Research Space (South Africa)

    Mkhabela, V

    2015-08-01

    Full Text Available confirmed the elemental composition of the scaffolds. The phase composition of the scaffolds was shown by XRD, which also indicated a decrease in crystallinity with the introduction of nanoclay. Biodegradability studies which were conducted in simulated...

  12. Electrospinning PCL Scaffolds Manufacture for Three-Dimensional Breast Cancer Cell Culture

    Directory of Open Access Journals (Sweden)

    Marc Rabionet

    2017-08-01

    Full Text Available In vitro cell culture is traditionally performed within two-dimensional (2D environments, providing a quick and cheap way to study cell properties in a laboratory. However, 2D systems differ from the in vivo environment and may not mimic the physiological cell behavior realistically. For instance, 2D culture models are thought to induce cancer stem cells (CSCs differentiation, a rare cancer cell subpopulation responsible for tumor initiation and relapse. This fact hinders the development of therapeutic strategies for tumors with a high relapse percentage, such as triple negative breast cancer (TNBC. Thus, three-dimensional (3D scaffolds have emerged as an attractive alternative to monolayer culture, simulating the extracellular matrix structure and maintaining the differentiation state of cells. In this work, scaffolds were fabricated through electrospinning different poly(ε-caprolactone-acetone solutions. Poly(ε-caprolactone (PCL meshes were seeded with triple negative breast cancer (TNBC cells and 15% PCL scaffolds displayed significantly (p < 0.05 higher cell proliferation and elongation than the other culture systems. Moreover, cells cultured on PCL scaffolds exhibited higher mammosphere forming capacity and aldehyde dehydrogenase activity than 2D-cultured cells, indicating a breast CSCs enrichment. These results prove the powerful capability of electrospinning technology in terms of poly(ε-caprolactone nanofibers fabrication. In addition, this study has demonstrated that electrospun 15% PCL scaffolds are suitable tools to culture breast cancer cells in a more physiological way and to expand the niche of breast CSCs. In conclusion, three-dimensional cell culture using PCL scaffolds could be useful to study cancer stem cell behavior and may also trigger the development of new specific targets against such malignant subpopulation.

  13. Practopoiesis: or how life fosters a mind.

    Science.gov (United States)

    Nikolić, Danko

    2015-05-21

    The mind is a biological phenomenon. Thus, biological principles of organization should also be the principles underlying mental operations. Practopoiesis states that the key for achieving intelligence through adaptation is an arrangement in which mechanisms laying at a lower level of organization, by their operations and interaction with the environment, enable creation of mechanisms laying at a higher level of organization. When such an organizational advance of a system occurs, it is called a traverse. A case of traverse is when plasticity mechanisms (at a lower level of organization), by their operations, create a neural network anatomy (at a higher level of organization). Another case is the actual production of behavior by that network, whereby the mechanisms of neuronal activity operate to create motor actions. Practopoietic theory explains why the adaptability of a system increases with each increase in the number of traverses. With a larger number of traverses, a system can be relatively small and yet, produce a higher degree of adaptive/intelligent behavior than a system with a lower number of traverses. The present analyses indicate that the two well-known traverses - neural plasticity and neural activity - are not sufficient to explain human mental capabilities. At least one additional traverse is needed, which is named anapoiesis for its contribution in reconstructing knowledge e.g., from long-term memory into working memory. The conclusions bear implications for brain theory, the mind-body explanatory gap, and developments of artificial intelligence technologies. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

  14. Visualizing Angiogenesis by Multiphoton Microscopy In Vivo in Genetically Modified 3D-PLGA/nHAp Scaffold for Calvarial Critical Bone Defect Repair.

    Science.gov (United States)

    Li, Jian; Jahr, Holger; Zheng, Wei; Ren, Pei-Gen

    2017-09-07

    The reconstruction of critically sized bone defects remains a serious clinical problem because of poor angiogenesis within tissue-engineered scaffolds during repair, which gives rise to a lack of sufficient blood supply and causes necrosis of the new tissues. Rapid vascularization is a vital prerequisite for new tissue survival and integration with existing host tissue. The de novo generation of vasculature in scaffolds is one of the most important steps in making bone regeneration more efficient, allowing repairing tissue to grow into a scaffold. To tackle this problem, the genetic modification of a biomaterial scaffold is used to accelerate angiogenesis and osteogenesis. However, visualizing and tracking in vivo blood vessel formation in real-time and in three-dimensional (3D) scaffolds or new bone tissue is still an obstacle for bone tissue engineering. Multiphoton microscopy (MPM) is a novel bio-imaging modality that can acquire volumetric data from biological structures in a high-resolution and minimally-invasive manner. The objective of this study was to visualize angiogenesis with multiphoton microscopy in vivo in a genetically modified 3D-PLGA/nHAp scaffold for calvarial critical bone defect repair. PLGA/nHAp scaffolds were functionalized for the sustained delivery of a growth factor pdgf-b gene carrying lentiviral vectors (LV-pdgfb) in order to facilitate angiogenesis and to enhance bone regeneration. In a scaffold-implanted calvarial critical bone defect mouse model, the blood vessel areas (BVAs) in PHp scaffolds were significantly higher than in PH scaffolds. Additionally, the expression of pdgf-b and angiogenesis-related genes, vWF and VEGFR2, increased correspondingly. MicroCT analysis indicated that the new bone formation in the PHp group dramatically improved compared to the other groups. To our knowledge, this is the first time multiphoton microscopy was used in bone tissue-engineering to investigate angiogenesis in a 3D bio-degradable scaffold in

  15. Knowledge scaffolding visualizations: A guiding framework

    Directory of Open Access Journals (Sweden)

    Elitsa Alexander

    2015-06-01

    Full Text Available In this paper we provide a guiding framework for understanding and selecting visual representations in the knowledge management (KM practice. We build on an interdisciplinary analogy between two connotations of the notion of “scaffolding”: physical scaffolding from an architectural-engineering perspective and scaffolding of the “everyday knowing in practice” from a KM perspective. We classify visual structures for knowledge communication in teams into four types of scaffolds: grounded (corresponding e.g., to perspectives diagrams or dynamic facilitation diagrams, suspended (e.g., negotiation sketches, argument maps, panel (e.g., roadmaps or timelines and reinforcing (e.g., concept diagrams. The article concludes with a set of recommendations in the form of questions to ask whenever practitioners are choosing visualizations for specific KM needs. Our recommendations aim at providing a framework at a broad-brush level to aid choosing a suitable visualization template depending on the type of KM endeavour.

  16. Nano/macro porous bioactive glass scaffold

    Science.gov (United States)

    Wang, Shaojie

    Bioactive glass (BG) and ceramics have been widely studied and developed as implants to replace hard tissues of the musculo-skeletal system, such as bones and teeth. Recently, instead of using bulk materials, which usually do not degrade rapidly enough and may remain in the human body for a long time, the idea of bioscaffold for tissue regeneration has generated much interest. An ideal bioscaffold is a porous material that would not only provide a three-dimensional structure for the regeneration of natural tissue, but also degrade gradually and, eventually be replaced by the natural tissue completely. Among various material choices the nano-macro dual porous BG appears as the most promising candidate for bioscaffold applications. Here macropores facilitate tissue growth while nanopores control degradation and enhance cell response. The surface area, which controls the degradation of scaffold can also be tuned by changing the nanopore size. However, fabrication of such 3D structure with desirable nano and macro pores has remained challenging. In this dissertation, sol-gel process combined with spinodal decomposition or polymer sponge replication method has been developed to fabricate the nano-macro porous BG scaffolds. Macropores up to 100microm are created by freezing polymer induced spinodal structure through sol-gel transition, while larger macropores (>200um) of predetermined size are obtained by the polymer sponge replication technique. The size of nanopores, which are inherent to the sol-gel method of glass fabrication, has been tailored using several approaches: Before gel point, small nanopores are generated using acid catalyst that leads to weakly-branched polymer-like network. On the other hand, larger nanopores are created with the base-catalyzed gel with highly-branched cluster-like structure. After the gel point, the nanostructure can be further modified by manipulating the sintering temperature and/or the ammonia concentration used in the solvent

  17. Mindfulness Is Associated With Treatment Response From Nonpharmacologic Exercise Interventions in Knee Osteoarthritis.

    Science.gov (United States)

    Lee, Augustine C; Harvey, William F; Price, Lori Lyn; Han, Xingyi; Driban, Jeffrey B; Wong, John B; Chung, Mei; McAlindon, Timothy E; Wang, Chenchen

    2017-11-01

    To examine the association between baseline mindfulness and response from exercise interventions in knee osteoarthritis (OA). Cohort study; responder analysis of a clinical trial subset. Urban tertiary care academic hospital. Participants with symptomatic, radiographic knee OA (N=86; mean age, 60y; 74% female; 48% white). Twelve weeks (twice per week) of Tai Chi or physical therapy exercise. Treatment response was defined using Osteoarthritis Research Society International criteria indicating meaningful improvements in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, WOMAC function, or Patient Global Assessment scores. At baseline, participants completed the Five Facet Mindfulness Questionnaire (mean total score, 142±17) and were grouped into 3 categories of total mindfulness: higher, medium, or lower. Relative risk (RR) ratios were used to compare treatment response across groups. Participants with higher total mindfulness were 38% (95% confidence interval [CI], 1.05-1.83) more likely to meet responder criteria than those with lower mindfulness. We found no significant difference between medium and lower mindfulness groups (RR=1.0; 95% CI, 0.69-1.44). Among the 5 mindfulness facets, medium acting-with-awareness was 46% (95% CI, 1.09-1.96) more likely to respond than lower acting-with-awareness, and higher acting-with-awareness was 34% more likely to respond, but this did not reach significance (95% CI, 0.97-1.86). In this study, higher mindfulness, primarily driven by its acting-with-awareness facet, was significantly associated with a greater likelihood of response to nonpharmacologic exercise interventions in knee OA. This suggests that mindfulness-cultivating interventions may increase the likelihood of response from exercise. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  18. Mindfulness as a Path of Women's Empowerment

    Directory of Open Access Journals (Sweden)

    Nadja FURLAN ŠTANTE

    2016-08-01

    Full Text Available The paper brings together social mindfulness as a path of empowerment for women within its concept of the interrelatedness of all beings in the web of life. The paradigm of social mindfulness is thus established as the foundation of feminist spirituality. The focus of this work is on the possibility of applying the ethics of mindfulness as a paradigm to interpersonal interrelatedness. The relations among humans, nature, reason and emotion in self-development are confronted with the paradigm of mindfulness. This paper carries out a theoretical analysis of the possibility of integrating the paradigm of mindfulness with the paradigm of feminist spirituality. In this view, the paradigm shift toward integrating spiritual and social justice and ecological balance is examined. It also examines possibility of transformation of negative gender stereotypes with the help of mindfulness, loving kindness, compassion and ethics. From this point of view, the application of mindfulness in education (especially childhood, primary and secondary schools is considered.

  19. Exploring arising moments and mindfulness in occupational therapists working in diverse clinical practice areas.

    Science.gov (United States)

    Reid, Denise; Naseer, Zahid

    2012-10-01

    An online survey was conducted with 72 Canadian occupational therapists to (1) explore if and how occupational therapists were aware of "arising moments" in clinical practice, which are moments that give rise to emotions, sensations, and thoughts, and (2) to examine therapists' responses to questions related to mindfulness. Participants described arising moments through an open-ended survey question. Framework analysis was used to develop key themes and subthemes. A modified Philadelphia Mindfulness Awareness (PHLMS) subscale with two additional survey questions "understanding of living in the moment and being present, and awareness of mindfulness" (sum = PAM) were used as indicators of mindfulness. There were significant differences in the means of PHLMS mindfulness among therapists working in diverse practice areas (F = 3.63, p = .009). Posthoc analysis revealed that therapists working in mental health had higher mean PHLMS-mindfulness scores than in all other groups. There were no significant differences in PAM mindfulness among the practice areas (ANOVA, F = 2.15, p = .08). However, posthoc tests showed that the participants in the mental health practice area had a significant difference with one group, general physical health. Findings have implications for practice in occupational therapy and education about mindfulness in occupational therapy.

  20. The relation between trait mindfulness and aggression in men seeking residential substance use treatment.

    Science.gov (United States)

    Shorey, Ryan C; Anderson, Scott; Stuart, Gregory L

    2015-06-01

    There has been an abundance of research in recent years on mindfulness, including mindfulness within individuals seeking substance use treatment. However, to date, there has been no research on whether trait mindfulness is associated with increased aggression among individuals seeking substance use treatment. Past research has demonstrated that individuals in substance use treatment evidence higher levels of aggression than non-substance abusers, and preliminary research has shown that trait mindfulness is inversely associated with aggression in non-substance-use treatment-seeking populations. The current study examined whether trait mindfulness was associated with aggression among men seeking residential substance use treatment (N = 116). Results demonstrated that lower trait mindfulness was associated with increased aggression (physical, verbal, and aggressive attitude). Moreover, this relation held for both verbal aggression and aggressive attitude after controlling for alcohol use, drug use, and age, all known predictors of aggression. Findings provide the first evidence that mindfulness is negatively associated with aggression among men in substance use treatment, which could have important implications for intervention. That is, mindfulness-based interventions may prove helpful for the treatment of both substance use and aggression. © The Author(s) 2014.

  1. SCAFFOLDING IN CONNECTIVIST MOBILE LEARNING ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ozlem OZAN

    2013-04-01

    Full Text Available Social networks and mobile technologies are transforming learning ecology. In this changing learning environment, we find a variety of new learner needs. The aim of this study is to investigate how to provide scaffolding to the learners in connectivist mobile learning environment: Ø to learn in a networked environment, Ø to manage their networked learning process, Ø to interact in a networked society, and Ø to use the tools belonging to the network society. The researcher described how Vygotsky's “scaffolding” concept, Berge’s “learner support” strategies, and Siemens’ “connectivism” approach can be used together to satisfy mobile learners’ needs. A connectivist mobile learning environment was designed for the research, and the research was executed as a mixed-method study. Data collection tools were Facebook wall entries, personal messages, chat records; Twitter, Diigo, blog entries; emails, mobile learning management system statistics, perceived learning survey and demographic information survey. Results showed that there were four major aspects of scaffolding in connectivist mobile learning environment as type of it, provider of it, and timing of it and strategies of it. Participants preferred mostly social scaffolding, and then preferred respectively, managerial, instructional and technical scaffolding. Social scaffolding was mostly provided by peers, and managerial scaffolding was mostly provided by instructor. Use of mobile devices increased the learner motivation and interest. Some participants stated that learning was more permanent by using mobile technologies. Social networks and mobile technologies made it easier to manage the learning process and expressed a positive impact on perceived learning.

  2. Simulations as Scaffolds in Science Education

    DEFF Research Database (Denmark)

    Renken, Maggie; Peffer, Melanie; Otrel-Cass, Kathrin

    This book outlines key issues for addressing the grand challenges posed to educators, developers, and researchers interested in the intersection of simulations and science education. To achieve this, the authors explore the use of computer simulations as instructional scaffolds that provide...... strategies and support when students are faced with the need to acquire new skills or knowledge. The monograph aims to provide insight into what research has reported on navigating the complex process of inquiry- and problem-based science education and whether computer simulations as instructional scaffolds...

  3. Scaffold Diversity from N-Acyliminium Ions

    DEFF Research Database (Denmark)

    Wu, Peng; Nielsen, Thomas E

    2017-01-01

    N-Acyliminium ions are powerful reactive species for the formation of carbon-carbon and carbon-heteroatom bonds. Strategies relying on intramolecular reactions of N-acyliminium intermediates, also referred to as N-acyliminium ion cyclization reactions, have been employed for the construction...... of structurally diverse scaffolds, ranging from simple bicyclic skeletons to complex polycyclic systems and natural-product-like compounds. This review aims to provide an overview of cyclization reactions of N-acyliminium ions derived from various precursors for the assembly of structurally diverse scaffolds...

  4. Scaffolds of polycaprolactone with hydroxyapatite fibers

    International Nuclear Information System (INIS)

    Cardoso, Guinea B.C.; Zavaglia, Cecilia A.C.; Arruda, Antonio Celso F.

    2009-01-01

    Scaffolds of poly (ε-caprolactone) has been studied in many researches in tissue engineering. The used of hydroxyapatite fibers, allowed increase its resistance mechanical, beside the character bioactive and osteoconductive. Improving, its role in tissue engineering. The aim in this study was developed polycaprolactone matrix with dispersed hydroxyapatite fibers. The characterizations were by scanning electron microscopy (SEM), X- Ray Diffractometer (XRD), X-Ray Fluorescence (XRF) and Energy dispersive X-Ray Detector (EDX). Was able reviewed its composition, morphology and possible contaminations. The results were scaffolds with porosity and distribution of the fibers in all its area. (author)

  5. Enhancing the bioactivity of Poly(lactic-co-glycolic acid scaffold with a nano-hydroxyapatite coating for the treatment of segmental bone defect in a rabbit model

    Directory of Open Access Journals (Sweden)

    Wang DX

    2013-05-01

    Full Text Available De-Xin Wang,1,* Yao He,2,* Long Bi1,* Ze-Hua Qu,2 Ji-Wei Zou,1 Zhen Pan,2 Jun-Jun Fan,1 Liang Chen,2 Xin Dong,1 Xiang-Nan Liu,2 Guo-Xian Pei,1 Jian-Dong Ding,21Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an, People's Republic of China; 2State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, People's Republic of China*These authors contributed equally to this workPurpose: Poly(lactic-co-glycolic acid (PLGA is excellent as a scaffolding matrix due to feasibility of processing and tunable biodegradability, yet the virgin scaffolds lack osteoconduction and osteoinduction. In this study, nano-hydroxyapatite (nHA was coated on the interior surfaces of PLGA scaffolds in order to facilitate in vivo bone defect restoration using biomimetic ceramics while keeping the polyester skeleton of the scaffolds.Methods: PLGA porous scaffolds were prepared and surface modification was carried out by incubation in modified simulated body fluids. The nHA coated PLGA scaffolds were compared to the virgin PLGA scaffolds both in vitro and in vivo. Viability and proliferation rate of bone marrow stromal cells of rabbits were examined. The constructs of scaffolds and autogenous bone marrow stromal cells were implanted into the segmental bone defect in the rabbit model, and the bone regeneration effects were observed.Results: In contrast to the relative smooth pore surface of the virgin PLGA scaffold, a biomimetic hierarchical nanostructure was found on the surface of the interior pores of the nHA coated PLGA scaffolds by scanning electron microscopy. Both the viability and proliferation rate of the cells seeded in nHA coated PLGA scaffolds were higher than those in PLGA scaffolds. For bone defect repairing, the radius defects had, after 12 weeks implantation of nHA coated PLGA scaffolds, completely recuperated with significantly better bone formation than in

  6. Bio-functionalized PCL nanofibrous scaffolds for nerve tissue engineering

    International Nuclear Information System (INIS)

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P.; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Ramakrishna, S.

    2010-01-01

    Surface properties of scaffolds such as hydrophilicity and the presence of functional groups on the surface of scaffolds play a key role in cell adhesion, proliferation and migration. Different modification methods for hydrophilicity improvement and introduction of functional groups on the surface of scaffolds have been carried out on synthetic biodegradable polymers, for tissue engineering applications. In this study, alkaline hydrolysis of poly (ε-caprolactone) (PCL) nanofibrous scaffolds was carried out for different time periods (1 h, 4 h and 12 h) to increase the hydrophilicity of the scaffolds. The formation of reactive groups resulting from alkaline hydrolysis provides opportunities for further surface functionalization of PCL nanofibrous scaffolds. Matrigel was attached covalently on the surface of an optimized 4 h hydrolyzed PCL nanofibrous scaffolds and additionally the fabrication of blended PCL/matrigel nanofibrous scaffolds was carried out. Chemical and mechanical characterization of nanofibrous scaffolds were evaluated using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, contact angle, scanning electron microscopy (SEM) and tensile measurement. In vitro cell adhesion and proliferation study was carried out after seeding nerve precursor cells (NPCs) on different scaffolds. Results of cell proliferation assay and SEM studies showed that the covalently functionalized PCL/matrigel nanofibrous scaffolds promote the proliferation and neurite outgrowth of NPCs compared to PCL and hydrolyzed PCL nanofibrous scaffolds, providing suitable substrates for nerve tissue engineering.

  7. Patterns of Scaffolding in Computer-Mediated Collaborative Inquiry

    Science.gov (United States)

    Lakkala, Minna; Muukkonen, Hanni; Hakkarainen, Kai

    2005-01-01

    There is wide agreement on the importance of scaffolding for student learning. Yet, models of individual and face-to-face scaffolding are not necessarily applicable to educational settings in which a group of learners is pursuing a process of inquiry mediated by technology. The scaffolding needed for such a process may be examined from three…

  8. A perception theory in mind-body medicine: guided imagery and mindful meditation as cross-modal adaptation.

    Science.gov (United States)

    Bedford, Felice L

    2012-02-01

    A new theory of mind-body interaction in healing is proposed based on considerations from the field of perception. It is suggested that the combined effect of visual imagery and mindful meditation on physical healing is simply another example of cross-modal adaptation in perception, much like adaptation to prism-displaced vision. It is argued that psychological interventions produce a conflict between the perceptual modalities of the immune system and vision (or touch), which leads to change in the immune system in order to realign the modalities. It is argued that mind-body interactions do not exist because of higher-order cognitive thoughts or beliefs influencing the body, but instead result from ordinary interactions between lower-level perceptual modalities that function to detect when sensory systems have made an error. The theory helps explain why certain illnesses may be more amenable to mind-body interaction, such as autoimmune conditions in which a sensory system (the immune system) has made an error. It also renders sensible erroneous changes, such as those brought about by "faith healers," as conflicts between modalities that are resolved in favor of the wrong modality. The present view provides one of very few psychological theories of how guided imagery and mindfulness meditation bring about positive physical change. Also discussed are issues of self versus non-self, pain, cancer, body schema, attention, consciousness, and, importantly, developing the concept that the immune system is a rightful perceptual modality. Recognizing mind-body healing as perceptual cross-modal adaptation implies that a century of cross-modal perception research is applicable to the immune system.

  9. A coupled diffusion-fluid pressure model to predict cell density distribution for cells encapsulated in a porous hydrogel scaffold under mechanical loading.

    Science.gov (United States)

    Zhao, Feihu; Vaughan, Ted J; Mc Garrigle, Myles J; McNamara, Laoise M

    2017-10-01

    Tissue formation within tissue engineering (TE) scaffolds is preceded by growth of the cells throughout the scaffold volume and attachment of cells to the scaffold substrate. It is known that mechanical stimulation, in the form of fluid perfusion or mechanical strain, enhances cell differentiation and overall tissue formation. However, due to the complex multi-physics environment of cells within TE scaffolds, cell transport under mechanical stimulation is not fully understood. Therefore, in this study, we have developed a coupled multiphysics model to predict cell density distribution in a TE scaffold. In this model, cell transport is modelled as a thermal conduction process, which is driven by the pore fluid pressure under applied loading. As a case study, the model is investigated to predict the cell density patterns of pre-osteoblasts MC3T3-e1 cells under a range of different loading regimes, to obtain an understanding of desirable mechanical stimulation that will enhance cell density distribution within TE scaffolds. The results of this study have demonstrated that fluid perfusion can result in a higher cell density in the scaffold region closed to the outlet, while cell density distribution under mechanical compression was similar with static condition. More importantly, the study provides a novel computational approach to predict cell distribution in TE scaffolds under mechanical loading. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Balancing mechanical strength with bioactivity in chitosan-calcium phosphate 3D microsphere scaffolds for bone tissue engineering: air- vs. freeze-drying processes.

    Science.gov (United States)

    Nguyen, D T; McCanless, J D; Mecwan, M M; Noblett, A P; Haggard, W O; Smith, R A; Bumgardner, J D

    2013-01-01

    The objective of this study was to evaluate the potential benefit of 3D composite scaffolds composed of chitosan and calcium phosphate for bone tissue engineering. Additionally, incorporation of mechanically weak lyophilized microspheres within those air-dried (AD) was considered for enhanced bioactivity. AD microsphere, alone, and air- and freeze-dried microsphere (FDAD) 3D scaffolds were evaluated in vitro using a 28-day osteogenic culture model with the Saos-2 cell line. Mechanical testing, quantitative microscopy, and lysozyme-driven enzymatic degradation of the scaffolds were also studied. FDAD scaffold showed a higher concentration (p < 0.01) in cells per scaffold mass vs. AD constructs. Collagen was ∼31% greater (p < 0.01) on FDAD compared to AD scaffolds not evident in microscopy of microsphere surfaces. Alternatively, AD scaffolds demonstrated a superior threefold increase in compressive strength over FDAD (12 vs. 4 MPa) with minimal degradation. Inclusion of FD spheres within the FDAD scaffolds allowed increased cellular activity through improved seeding, proliferation, and extracellular matrix production (as collagen), although mechanical strength was sacrificed through introduction of the less stiff, porous FD spheres.

  11. Tubular scaffolds of gelatin and poly(ε-caprolactone)-block-poly(γ-glutamic acid) blending hydrogel for the proliferation of the primary intestinal smooth muscle cells of rats

    International Nuclear Information System (INIS)

    Jwo, Shyh-Chuan; Chiu, Chu-Hua; Hsieh, Ming-Fa; Tang, Shye-Jye

    2013-01-01

    The proper regeneration of intestinal muscle for functional peristalsis is the most challenging aspect of current small intestine tissue engineering. This study aimed to fabricate a hydrogel scaffold for the proliferation of intestinal smooth muscle cells (ISMCs). Tubular porous scaffolds of 10–20 wt% gelatin and 0.05–0.1 wt% poly(ε-caprolactone)-block-poly(γ-glutamic acid) blending hydrogel were cross-linked by carbodiimide and succinimide in an annular space of a glass mold. The scaffolds with higher gelatin contents degraded slower in the phosphate buffer solution. In rheological measurements, the hydrated scaffolds were elastic (all tangent delta <0.45); they responded differentially to frequency, indicating a complete viscoelastic property that is beneficial for soft tissue regeneration. Isolated rat ISMCs, with the characteristic biomarkers α-SMA, calponin and myh11, were loaded into the scaffolds by using either static or centrifugal methods. The average cell density inside the scaffolds increased in a time-dependent manner in most scaffolds of both seeding groups, although at early time points (seven days) the centrifugal seeding method trapped cells more efficiently and yielded a higher cell density than the static seeding method. The static seeding method increased the cell density from 7.5-fold to 16.3-fold after 28 days, whereas the centrifugal procedure produced a maximum increase of only 2.4-fold in the same period. In vitro degradation data showed that 50–80% of the scaffold was degraded by the 14th day. However, the self-secreted extracellular matrix maintained the integrity of the scaffolds for cell proliferation and spreading for up to 28 days. Confocal microscopic images revealed cell–cell contacts with the formation of a 3D network, demonstrating that the fabricated scaffolds were highly biocompatible. Therefore, these polymeric biomaterials hold great promise for in vivo applications of intestinal tissue engineering. (paper)

  12. Biodegradable polycaprolactone-chitosan three-dimensional scaffolds fabricated by melt stretching and multilayer deposition for bone tissue engineering: assessment of the physical properties and cellular response

    International Nuclear Information System (INIS)

    Thuaksuban, Nuttawut; Nuntanaranont, Thongchai; Suttapreyasri, Srisurang; Pattanachot, Wachirapan; Cheung, Lim Kwong

    2011-01-01

    Fabrication of polycaprolactone (PCL)-chitosan (CS) three-dimensional (3D) scaffolds using the novel technique of melt stretching and multilayer deposition was introduced. In brief, firstly, the PCL-CS monofilaments containing 0% (pure PCL), 10%, 20% and 30% CS by weight were fabricated by melting and stretching processes. Secondly, the desired multilayer (3D) scaffolds were fabricated by arranging and depositing the filaments. Physical properties of the filaments and the scaffolds were evaluated. MC3T3-E1 cell lines were seeded on the scaffolds to assess their proliferation. A typical micro-groove pattern was found on the surfaces of pure PCL filaments due to stretching. The filaments of PCL-30%CS had the highest tendency of fracture during stretching and could not be used to form the scaffold. Increasing CS proportions tended to reduce the micro-groove pattern, surface roughness, tensile strength and elasticity of the filaments, whilst compressive strength of the PCL-CS scaffolds was not affected. The average pore size and porosity of the scaffolds were 536.90 ± 17.91 μm and 45.99 ± 2.8% respectively. Over 60 days, degradation of the scaffolds gradually increased (p > 0.05). The more CS containing scaffolds were found to increase in water uptake, but decrease in degradation rate. During the culture period, the growth of the cells in PCL-CS groups was significantly higher than in the pure PCL group (p < 0.05). On culture-day 21, the growth in the PCL-20%CS group was significantly higher than the other groups (p < 0.05). In conclusion, the PCL-20%CS scaffolds obtained the optimum results in terms of physical properties and cellular response.

  13. Biodegradable polycaprolactone-chitosan three-dimensional scaffolds fabricated by melt stretching and multilayer deposition for bone tissue engineering: assessment of the physical properties and cellular response

    Energy Technology Data Exchange (ETDEWEB)

    Thuaksuban, Nuttawut; Nuntanaranont, Thongchai; Suttapreyasri, Srisurang [Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Prince of Songkla University, Kanjanavanij Road, Hatyai, Songkhla, 90112 (Thailand); Pattanachot, Wachirapan [Polymer Science Program, Faculty of Science, Prince of Songkla University, Kanjanavanij Road, Hatyai, Songkhla, 90112 (Thailand); Cheung, Lim Kwong, E-mail: nuttawut.t@psu.ac.t [Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, the University of Hong Kong, Hong Kong (China)

    2011-02-15

    Fabrication of polycaprolactone (PCL)-chitosan (CS) three-dimensional (3D) scaffolds using the novel technique of melt stretching and multilayer deposition was introduced. In brief, firstly, the PCL-CS monofilaments containing 0% (pure PCL), 10%, 20% and 30% CS by weight were fabricated by melting and stretching processes. Secondly, the desired multilayer (3D) scaffolds were fabricated by arranging and depositing the filaments. Physical properties of the filaments and the scaffolds were evaluated. MC3T3-E1 cell lines were seeded on the scaffolds to assess their proliferation. A typical micro-groove pattern was found on the surfaces of pure PCL filaments due to stretching. The filaments of PCL-30%CS had the highest tendency of fracture during stretching and could not be used to form the scaffold. Increasing CS proportions tended to reduce the micro-groove pattern, surface roughness, tensile strength and elasticity of the filaments, whilst compressive strength of the PCL-CS scaffolds was not affected. The average pore size and porosity of the scaffolds were 536.90 {+-} 17.91 {mu}m and 45.99 {+-} 2.8% respectively. Over 60 days, degradation of the scaffolds gradually increased (p > 0.05). The more CS containing scaffolds were found to increase in water uptake, but decrease in degradation rate. During the culture period, the growth of the cells in PCL-CS groups was significantly higher than in the pure PCL group (p < 0.05). On culture-day 21, the growth in the PCL-20%CS group was significantly higher than the other groups (p < 0.05). In conclusion, the PCL-20%CS scaffolds obtained the optimum results in terms of physical properties and cellular response.

  14. The Mechanics of the Mind

    OpenAIRE

    Dmitry A. Sklyarov

    2015-01-01

    The article deals with the question of building a general concept that can reconcile the concept of "brain" and "mind", that is, as a biological brain creates subjective thinking. The research method is based on the revision of the basic concepts and the formation of logical chains of thought from the beginning of the formation of the brain before the onset of subjective thought processes. All displayed investigation confirmed the concept of logical algorithms practical facts. Describes the c...

  15. Pavlov and the mind-body problem.

    Science.gov (United States)

    Windholz, G

    1997-01-01

    I. P. Pavlov claimed that the mind-body problem would ultimately be resolved by empirical methods, rather than by rational arguments. A committed monist, Pavlov was confronted by dualism in the case of an hysterical person. Under normal conditions, her body's left side was insensitive to pain, but when she was hypnotized, there was a reversal of her sensitivity to pain, with the right side becoming insensitive. Pavlov acknowledged that the divergence between stimulation and response suggested dualism, yet condemned his disciple G.P. Zelenyĭ as well as Charles S. Sherrington, for their dualistic tendencies. Pavlov's continuous adherence to monism it attributed to the influence of popular scientific books that he read during his adolescence. The books maintained that science was based upon monism. Pavlov proposed that by introducing the concept of emotions, an hysterical person's condition could be explained within the framework of his theory of higher nervous activity, thereby obviating the need to change his paradigm.

  16. Higher Education

    African Journals Online (AJOL)

    Kunle Amuwo: Higher Education Transformation: A Paradigm Shilt in South Africa? ... ty of such skills, especially at the middle management levels within the higher ... istics and virtues of differentiation and diversity. .... may be forced to close shop for lack of capacity to attract ..... necessarily lead to racial and gender equity,.

  17. Mindfulness, Quality of Life, and Severity of Depressive Symptoms Among Patients With Schizophrenia and Patients With Major Depressive Disorder.

    Science.gov (United States)

    Rayan, Ahmad Hussien Rateb

    2017-05-01

    The current study used a descriptive correlational design to examine the relationship between mindfulness and quality of life (QOL) among patients with schizophrenia (n = 160) and patients with major depressive disorder (MDD) (n = 161), controlling for demographic and clinical variables. Participants completed self-reported questionnaires regarding demographic variables, severity of depression, QOL, and mindfulness. Patients diagnosed with MDD had higher mindfulness scores than patients diagnosed with schizophrenia. Mindfulness scores were significantly associated with the severity of depression among participants. After controlling for the demographic variables and severity of depressive symptoms, mindfulness had a unique variance in QOL among patients with schizophrenia, but not among patients with MDD. The current study provides preliminary evidence regarding the role of mindfulness in improving depressive symptoms and the overall QOL among patients diagnosed with mental illness. [Journal of Psychosocial Nursing and Mental Health Services, 55(5), 40-50.]. Copyright 2017, SLACK Incorporated.

  18. Hearts and minds.

    Science.gov (United States)

    Naylor, A R

    2012-01-01

    The American Heart Association liberalised guidelines for carotid stenting (CAS) into average risk patients based on the following interpretations and assumptions; (i) CAS doubles the risk of procedural stroke; (ii) CEA doubles the risk of procedural myocardial infarction (MI); (iii) peri-operative MI significantly reduces long-term survival; (iv) poorer long-term survival is attributable to a greater proportion of CEA patients dying after their peri-operative MI. (v) reduced survival in CEA patients suffering a peri-operative MI offsets any benefit conferred by the lower procedural stroke risk so that; (vi) CAS is considered equivalent to CEA and may even be safer in those considered high risk for procedural MI. However, this much publicised rationale is flawed by the simple fact that the poorer survival rates observed in CREST were not attributable to a greater proportion of CEA patients dying following their procedural MI. In fact, a relatively higher proportion of CAS patients suffering a peri-operative MI died during follow-up. This observation changes how the literature should be interpreted. The clinical reality is that up to 10% of patients will suffer a stroke within seven days of their index TIA and the benefits of intervening in the hyperacute period after onset of symptoms (ie offering greater stroke prevention) will far outweigh any potential consequences of peri-operative MI and reduced life expectancy. Peri-operative MI should inform, but not drive the current debate. More importantly, it should not deflect attention away from the most important management priority; the prevention of stroke. This is one situation where the heart should not rule the head! Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  19. Trait mindfulness helps shield decision-making from translating into health-risk behavior.

    Science.gov (United States)

    Black, David S; Sussman, Steve; Johnson, C Anderson; Milam, Joel

    2012-12-01

    The cognitive tendency toward mindfulness may influence the enactment of health and risk behaviors by its bringing increased attention to and awareness of decision-making processes underlying behavior. The present study examined the moderating effect of trait mindfulness on associations between intentions to smoke (ITS)/smoking refusal self-efficacy (SRSE) and smoking frequency. Self-reports from Chinese adolescents (N = 5,287; mean age = 16.2 years, standard deviation = .7; 48.8% female) were collected in 24 schools. Smoking frequency was regressed on latent factor interactions Mindful Attention Awareness Scale*ITS and Mindful Attention Awareness Scale*SRSE, adjusting for school clustering effects and covariates. Both interaction terms were significant in cross-sectional analyses and showed that high ITS predicted higher smoking frequency among those low, relative to high, in trait mindfulness, whereas low SRSE predicted higher smoking frequency among those low, relative to high, in trait mindfulness. Findings suggest trait mindfulness possibly shields against decision-making processes that place adolescents at risk for smoking. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  20. Mindfulness and Affective Responses to Treadmill Walking in Individuals with Low Intrinsic Motivation to Exercise

    Science.gov (United States)

    COX, ANNE E.; ROBERTS, MADELINE A.; CATES, HAILEY L.; MCMAHON, AMANDA K.

    2018-01-01

    An aversion to the sensations of physical exertion can deter engagement in physical activity. This is due in part to an associative focus in which individuals are attending to uncomfortable interoceptive cues. The purpose of this study was to test the effect of mindfulness on affective valence, ratings of perceived exertion (RPE), and enjoyment during treadmill walking. Participants (N=23; Mage=19.26, SD = 1.14) were only included in the study if they engaged in no more than moderate levels of physical activity and reported low levels of intrinsic motivation. They completed three testing sessions including a habituation session to determine the grade needed to achieve 65% of heart rate reserve (HRR); a control condition in which they walked at 65% of HRR for 10 minutes and an experimental condition during which they listened to a mindfulness track that directed them to attend to the physical sensations of their body in a nonjudgmental manner during the 10-minute walk. ANOVA results showed that in the mindfulness condition, affective valence was significantly more positive (p = .02, ηp2 = .22), enjoyment and mindfulness of the body were higher (p mindfulness of the body was moderately associated with higher enjoyment (p mindfulness but not the control condition. Results suggest that mindfulness during exercise is associated with more positive affective responses. PMID:29541336

  1. Fluorescent composite scaffolds made of nanodiamonds/polycaprolactone

    Science.gov (United States)

    Cao, Li; Hou, Yanwen; Lafdi, Khalid; Urmey, Kirk

    2015-11-01

    Polycaprolactone (PCL) has been widely studied for biological applications. Biodegradable PCL fibrous scaffold can work as an appropriate substrate for tissue regeneration. In this letter, fluorescent nanodiamonds (FNDs) were prepared after surface passivation with octadecylamine. The FNDs were then mixed with PCL polymer and subsequently electrospun into FNDs/PCL fibrous scaffolds. The obtained scaffolds not only exhibited photoluminescence, but also showed reinforced mechanical strength. Toxicity study indicated FNDs/PCL scaffolds were nontoxic. This biocompatible fluorescent composite fibrous scaffold can support in vitro cell growth and also has the potential to act as an optical probe for tissue engineering application in vitro and in vivo.

  2. Preparation of Porous Scaffolds from Silk Fibroin Extracted from the Silk Gland of Bombyx mori (B. mori

    Directory of Open Access Journals (Sweden)

    Liangjun Zhu

    2012-06-01

    Full Text Available In order to use a simple and ecofriendly method to prepare porous silk scaffolds, aqueous silk fibroin solution (ASF was extracted from silk gland of 7-day-old fifth instar larvae of Bombyx mori (B. mori. SDS-page analysis indicated that the obtained fibroin had a molecular weight higher than 200 kDa. The fabrication of porous scaffolds from ASF was achieved by using the freeze-drying method. The pore of porous scaffolds is homogenous and tends to become smaller with an increase in the concentration of ASF. Conversely, the porosity is decreased. The porous scaffolds show impressive compressive strength which can be as high as 6.9 ± 0.4 MPa. Furthermore, ASF has high cell adhesion and growth activity. It also exhibits high ALP activity. This implies that porous scaffolds prepared from ASF have biocompatibility. Therefore, the porous scaffolds prepared in this study have potential application in tissue engineering due to the impressive compressive strength and biocompatibility.

  3. "Scaffolding" through Talk in Groupwork Learning

    Science.gov (United States)

    Panselinas, Giorgos; Komis, Vassilis

    2009-01-01

    In the present study, we develop and deploy a conceptual framework of "scaffolding" in groupwork learning, through the analysis of the pursuit of a learning goal over time. The analysis follows individuals' different experiences of an interaction as well as collective experiences, considering individual attainment as a result of a bi-directional…

  4. Acellular organ scaffolds for tumor tissue engineering

    Science.gov (United States)

    Guller, Anna; Trusova, Inna; Petersen, Elena; Shekhter, Anatoly; Kurkov, Alexander; Qian, Yi; Zvyagin, Andrei

    2015-12-01

    Rationale: Tissue engineering (TE) is an emerging alternative approach to create models of human malignant tumors for experimental oncology, personalized medicine and drug discovery studies. Being the bottom-up strategy, TE provides an opportunity to control and explore the role of every component of the model system, including cellular populations, supportive scaffolds and signalling molecules. Objectives: As an initial step to create a new ex vivo TE model of cancer, we optimized protocols to obtain organ-specific acellular matrices and evaluated their potential as TE scaffolds for culture of normal and tumor cells. Methods and results: Effective decellularization of animals' kidneys, ureter, lungs, heart, and liver has been achieved by detergent-based processing. The obtained scaffolds demonstrated biocompatibility and growthsupporting potential in combination with normal (Vero, MDCK) and tumor cell lines (C26, B16). Acellular scaffolds and TE constructs have been characterized and compared with morphological methods. Conclusions: The proposed methodology allows creation of sustainable 3D tumor TE constructs to explore the role of organ-specific cell-matrix interaction in tumorigenesis.

  5. Teacher Scaffolding of Oral Language Production

    Science.gov (United States)

    George, May G.

    2011-01-01

    This research involved two observational studies. It explored the scaffolding processes as part of classroom pedagogy. The research shed light on the way a teacher's instructional methodology took shape in the classroom. The target event for this study was the time in which a novice learner was engaged publicly in uttering a sentence in Arabic in…

  6. Membrane supported scaffold architectures for tissue engineering

    NARCIS (Netherlands)

    Bettahalli Narasimha, M.S.

    2011-01-01

    Tissue engineering aims at restoring or regenerating a damaged tissue. Often the tissue recreation occurs by combining cells, derived from a patient biopsy, onto a 3D porous matrix, functioning as a scaffold. One of the current limitations of tissue engineering is the inability to provide sufficient

  7. Communication Scaffolds for Project Management in PBL

    Science.gov (United States)

    Sasaki, Shigeru; Arai, Masayuki; Takai, Kumiko; Ogawa, Mitsuhiro; Watanabe, Hiroyoshi

    2017-01-01

    In this study, the role-playing situation and the system requirement list are adopted into project-based learning classes to develop web applications. In the classes, the third-year undergraduate project managers communicate with the client of the project rolled by teachers on the Web bulletin board. These are expected to act as scaffolds to…

  8. Polylactic acid organogel as versatile scaffolding technique

    NARCIS (Netherlands)

    Punet, Xavier; Levato, Riccardo; Bataille, Isabelle; Letourneur, Didier; Engel, Elisabeth; Mateos-Timoneda, Miguel A

    2017-01-01

    Tissue engineering requires scaffolding techniques based on non-toxic processes that permits the fabrication of constructs with tailored properties. Here, a two-step methodology based on the gelation and precipitation of the poly(lactic) acid/ethyl lactate organogel system is presented. With this

  9. Comparison of TALEN scaffolds in Xenopus tropicalis

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    Keisuke Nakajima

    2013-11-01

    Transcription activator-like effector nucleases (TALENs are facile and potent tools used to modify a gene of interest for targeted gene knockout. TALENs consist of an N-terminal domain, a DNA-binding domain, and a C-terminal domain, which are derived from a transcription activator-like effector, and the non-specific nuclease domain of FokI. Using Xenopus tropicalis (X. tropicalis, we compared the toxicities and somatic mutation activities of four TALEN architectures in a side-by-side manner: a basic TALEN, a scaffold with the same truncated N- and C-terminal domains as GoldyTALEN, a scaffold with the truncated N- and C-terminal domains and an obligate heterodimeric nuclease domain, and a scaffold with the truncated N- and C-terminal domains and an obligate heterodimeric Sharkey nuclease domain. The strongest phenotype and targeted somatic gene mutation were induced by the injection of TALEN mRNAs containing the truncated N- and C-terminal domains and an obligate heterodimeric nuclease domain. The obligate heterodimeric TALENs exhibited reduced toxicity compared to the homodimeric TALENs, and the homodimeric GoldyTALEN-type scaffold showed both a high activity of somatic gene modification and high toxicity. The Sharkey mutation in the heterodimeric nuclease domain reduced the TALEN-mediated somatic mutagenesis.

  10. Enhancing Student Learning through Scaffolded Client Projects

    Science.gov (United States)

    Tomlinson, Elizabeth

    2017-01-01

    This article reports on the current status of client projects (CPs) in business communication courses, provides a scaffolded model for implementing CP, and assesses student learning in CPs. Using a longitudinal mixed method research design, survey data and qualitative materials from six semesters are presented. The instructor survey indicated need…

  11. Muscle fragments on a scaffold in rats

    DEFF Research Database (Denmark)

    Jangö, Hanna; Gräs, Søren; Christensen, Lise

    2015-01-01

    -PLGA scaffolds seeded with autologous MFF affected some histological and biomechanical properties of native tissue repair in an abdominal wall defect model in rats. The method thus appears to be a simple tissue engineering concept with potential relevance for native tissue repair of POP....

  12. Biodegradable elastomeric scaffolds for soft tissue engineering

    NARCIS (Netherlands)

    Pêgo, A.P.; Poot, Andreas A.; Grijpma, Dirk W.; Feijen, Jan

    2003-01-01

    Elastomeric copolymers of 1,3-trimethylene carbonate (TMC) and ε-caprolactone (CL) and copolymers of TMC and D,L-lactide (DLLA) have been evaluated as candidate materials for the preparation of biodegradable scaffolds for soft tissue engineering. TMC-DLLA copolymers are amorphous and degrade more

  13. Synergistic intrafibrillar/extrafibrillar mineralization of collagen scaffolds based on a biomimetic strategy to promote the regeneration of bone defects

    Directory of Open Access Journals (Sweden)

    Wang Y

    2016-05-01

    Full Text Available Yao Wang,1 Ngo Van Manh,1,2 Haorong Wang,1 Xue Zhong,1 Xu Zhang,1 Changyi Li1 1School of Dentistry, Hospital of Stomatology, Tianjin Medical University, Tianjin, People’s Republic of China; 2Thaibinh University of Medicine and Pharmacy, Thaibinh, Vietnam Abstract: The mineralization of collagen scaffolds can improve their mechanical properties and biocompatibility, thereby providing an appropriate microenvironment for bone regeneration. The primary purpose of the present study is to fabricate a synergistically intra- and extrafibrillar mineralized collagen scaffold, which has many advantages in terms of biocompatibility, biomechanical properties, and further osteogenic potential. In this study, mineralized collagen scaffolds were fabricated using a traditional mineralization method (ie, immersed in simulated body fluid as a control group and using a biomimetic method based on the polymer-induced liquid precursor process as an experimental group. In the polymer-induced liquid precursor process, a negatively charged polymer, carboxymethyl chitosan (CMC, was used to stabilize amorphous calcium phosphate (ACP to form nanocomplexes of CMC/ACP. Collagen scaffolds mineralized based on the polymer-induced liquid precursor process were in gel form such that nanocomplexes of CMC/ACP can easily be drawn into the interstices of the collagen fibrils. Scanning electron microscopy and transmission electron microscopy were used to examine the porous micromorphology and synergistic mineralization pattern of the collagen scaffolds. Compared with simulated body fluid, nanocomplexes of CMC/ACP significantly increased the modulus of the collagen scaffolds. The results of in vitro experiments showed that the cell count and differentiated degrees in the experimental group were higher than those in the control group. Histological staining and micro-computed tomography showed that the amount of new bone regenerated in the experimental group was larger than that in the

  14. Biocomposite scaffolds based on electrospun poly(3-hydroxybutyrate) nanofibers and electrosprayed hydroxyapatite nanoparticles for bone tissue engineering applications

    International Nuclear Information System (INIS)

    Ramier, Julien; Bouderlique, Thibault; Stoilova, Olya; Manolova, Nevena; Rashkov, Iliya; Langlois, Valérie; Renard, Estelle; Albanese, Patricia; Grande, Daniel

    2014-01-01

    The electrospinning technique combined with the electrospraying process provides a straightforward and versatile approach for the fabrication of novel nanofibrous biocomposite scaffolds with structural, mechanical, and biological properties potentially suitable for bone tissue regeneration. In this comparative investigation, three types of poly(3-hydroxybutyrate) (PHB)-based scaffolds were engineered: (i) PHB mats by electrospinning of a PHB solution, (ii) mats of PHB/hydroxyapatite nanoparticle (nHA) blends by electrospinning of a mixed solution containing PHB and nHAs, and (iii) mats constituted of PHB nanofibers and nHAs by simultaneous electrospinning of a PHB solution and electrospraying of a nHA dispersion. Scaffolds based on PHB/nHA blends displayed improved mechanical properties compared to those of neat PHB mats, due to the incorporation of nHAs within the fibers. The electrospinning/electrospraying approach afforded biocomposite scaffolds with lower mechanical properties, due to their higher porosity, but they displayed slightly better biological properties. In the latter case, the bioceramic, i.e. nHAs, largely covered the fiber surface, thus allowing for a direct exposure to cells. The 21 day-monitoring through the use of MTS assays and SEM analyses demonstrated that human mesenchymal stromal cells (hMSCs) remained viable on PHB/nHA biocomposite scaffolds and proliferated continuously until reaching confluence. - Highlights: • Three different types of PHB-based scaffolds are engineered and thoroughly investigated. • The combination of electrospinning and electrospraying affords original nanofibrous biocomposite scaffolds. • PHB-based scaffolds show a strong capability of supporting viable cell development for 21 days

  15. Biocomposite scaffolds based on electrospun poly(3-hydroxybutyrate) nanofibers and electrosprayed hydroxyapatite nanoparticles for bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Ramier, Julien [Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS, Université Paris-Est Créteil, 2, rue Henri Dunant, 94320 Thiais (France); Bouderlique, Thibault [Laboratoire “Croissance, Réparation et Régénération Tissulaires”, EAC 7149 CNRS, Université Paris-Est Créteil, 61, avenue du Général de Gaulle, 94010 Créteil (France); Stoilova, Olya; Manolova, Nevena; Rashkov, Iliya [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St., bl. 103A, BG-1113 Sofia (Bulgaria); Langlois, Valérie; Renard, Estelle [Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS, Université Paris-Est Créteil, 2, rue Henri Dunant, 94320 Thiais (France); Albanese, Patricia [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St., bl. 103A, BG-1113 Sofia (Bulgaria); Grande, Daniel, E-m