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1.
Psychosom Med ; 85(1): 79-88, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36516317

RESUMO

OBJECTIVE: Symptom perception in pathological illness anxiety (PIA) might be biased so that somatic signals are overreported. In the somatic signal detection task (SSDT), performance in detecting weak tactile stimuli gives information on overreporting or underreporting of stimuli. This task has not yet been applied in PIA. METHODS: Participants with PIA (n = 44) and healthy controls (n = 40) underwent two versions of the SSDT in randomized order. In the original version, tactile and auxiliary light-emitting diode (LED) stimuli were each presented in half of the trials. In the adapted version, illness or neutral words were presented alongside tactile stimuli. Participants also conducted a heartbeat mental tracking task. RESULTS: We found significantly higher sensitivity and a more liberal response bias in LED versus no-LED trials, but no significant differences between word types. An interaction effect showed a more pronounced increase of sensitivity from no LED to LED trials in participants with PIA when compared with the adapted SSDT and control group (F(1,76) = 5.34, p = .024, η2 = 0.066). Heartbeat perception scores did not differ between groups (BF01 of 3.63). CONCLUSIONS: The increase in sensitivity from no LED to LED trials in participants with PIA suggests stronger multisensory integration. Low sensitivity in the adapted SSDT indicates that attentional resources were exhausted by processing word stimuli. Word effects on response bias might have carried over to the original SSDT when the word version was presented first, compromising group effects regarding bias. TRIAL REGISTRATION: The study was preregistered on OSF (https://osf.io/sna5v/).


Assuntos
Percepção do Tato , Humanos , Ansiedade , Transtornos de Ansiedade , Atenção , Tato , Percepção do Tato/fisiologia
2.
Psychosom Med ; 85(9): 778-784, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37594228

RESUMO

OBJECTIVE: Biased interoception decoupled from physiology might be relevant in the etiology of pathological illness anxiety (PIA). Empirical evidence for interoceptive deviations in illness anxiety is scarce but potentially informative to optimize treatments. We hypothesized that persons with PIA differ fundamentally in the classification of bodily sensations from those without PIA. METHODS: In a respiratory categorization task, participants breathed into a pulmonary training device. Inspiration effort was varied by eight resistive loads. The lower/higher four loads were introduced as belonging to arbitrary categories "A"/"B," respectively. Participants memorized respiratory sensations in a first experimental block and were asked to label the resistances in a second block. We calculated the sensitivity of resistance classification according to category and response bias in terms of categorical misclassification. Data of 39 participants with PIA and 35 controls were compared with regard to sensitivity and response bias by group, resistive load, and their interaction in a multiple regression. RESULTS: With similar sensitivity, patients more often labeled loads above the categorical border erroneously as belonging to category A, thus underestimating their resistance ( ß = -0.06, p = .001; η2 = 0.02). CONCLUSIONS: Individuals with PIA showed a systematic "wait and see" approach. Altered respiroception in PIA might stem from biased perception during training phase, the recognition phase, biased memory, or a combination of these. Its exact characteristics remain unknown, and future research must address the challenge of developing reliable and valid paradigms accounting for the variability of interoceptive biases. REGISTRATION: This work was preregistered on OSF ( https://osf.io/9shcw ).


Assuntos
Interocepção , Humanos , Interocepção/fisiologia , Ansiedade , Transtornos de Ansiedade , Taxa Respiratória , Sensação
3.
Int J Mol Sci ; 24(12)2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37373482

RESUMO

Advances in spine surgery enable technically safe interventions in older patients with disabling spine disease, yet postoperative delirium (POD) poses a serious risk for postoperative recovery. This study investigates biomarkers of pro-neuroinflammatory states that may help objectively define the pre-operative risk for POD. This study enrolled patients aged ≥60 scheduled for elective spine surgery under general anesthesia. Biomarkers for a pro-neuroinflammatory state included S100 calcium-binding protein ß (S100ß), brain-derived neurotrophic factor (BDNF), Gasdermin D, and the soluble ectodomain of the triggering receptor expressed on myeloid cells 2 (sTREM2). Postoperative changes of Interleukin-6 (IL-6), Interleukin-1ß (IL-1ß), and C-reactive protein (CRP) were assessed as markers of systemic inflammation preoperatively, intraoperatively, and early postoperatively (up to 48 h). Patients with POD (n = 19, 75.7 ± 5.8 years) had higher pre-operative levels of sTREM2 (128.2 ± 69.4 pg/mL vs. 97.2 ± 52.0 pg/mL, p = 0.049) and Gasdermin D (2.9 ± 1.6 pg/mL vs. 2.1 ± 1.4 pg/mL, p = 0.29) than those without POD (n = 25, 75.6 ± 5.1 years). STREM2 was additionally a predictor for POD (OR = 1.01/(pg/mL) [1.00-1.03], p = 0.05), moderated by IL-6 (Wald-χ2 = 4.06, p = 0.04). Patients with POD additionally showed a significant increase in IL-6, IL-1ß, and S100ß levels on the first postoperative day. This study identified higher levels of sTREM2 and Gasdermin D as potential markers of a pro-neuroinflammatory state that predisposes to the development of POD. Future studies should confirm these results in a larger cohort and determine their potential as an objective biomarker to inform delirium prevention strategies.


Assuntos
Delírio , Delírio do Despertar , Humanos , Idoso , Interleucina-6/metabolismo , Delírio/diagnóstico , Delírio/etiologia , Gasderminas , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Biomarcadores/metabolismo
4.
Psychosom Med ; 83(1): 94-100, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33141791

RESUMO

OBJECTIVE: According to the predictive processing theory of somatic symptom generation, body sensations are determined by somatosensory input and central nervous predictions about this input. We examined how expectations shape predictions and consequently bodily perceptions in a task eliciting illusory sensations as laboratory analogue of medically unexplained symptoms. METHODS: Using the framework of signal detection theory, the influence of sham Wi-Fi on response bias (c) and somatosensory sensitivity (d') for tactile stimuli was examined using the somatic signal detection task (SSDT). A healthy student sample (n = 83) completed the SSDT twice (sham Wi-Fi on/off) in a randomized order after watching a film that promoted adverse health effects of electromagnetic fields. RESULTS: When expecting a Wi-Fi signal to be present, participants showed a significantly more liberal response bias c (p = .010, ηp2 = 0.08) for tactile stimuli in the SSDT as evidence of a higher propensity to experience somatosensory illusions. No significant alteration of somatosensory sensitivity d' (p = .76, ηp2 < 0.002) was observed. CONCLUSIONS: Negative expectations about the harmfulness of electromagnetic fields may foster the occurrence of illusory symptom perceptions via alterations in the somatosensory decision criterion. The findings are in line with central tenets of the predictive processing account of somatic symptom generation. This account proposes a decoupling of percept and somatosensory input so that perception becomes increasingly dependent on predictions. This biased perception is regarded as a risk factor for somatic symptom disorders.


Assuntos
Ilusões , Sintomas Inexplicáveis , Percepção do Tato , Campos Eletromagnéticos , Humanos , Tato
5.
Psychopathology ; 54(3): 144-149, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33951648

RESUMO

INTRODUCTION: People suffering from fibromyalgia syndrome report various difficulties in emotional processing, possibly resulting from changes in bodily perception (interoception). In our study, we investigated the relationships between interoceptive sensibility (IS) and two disease-relevant emotional components (alexithymia and emotion regulation) in fibromyalgia sufferers compared to healthy individuals. METHODS: Fifty-five fibromyalgia sufferers and 55 healthy individuals, matched with regard to age and gender, participated in our cross-sectional study. All participants completed the following self-report measures: the Multidimensional Assessment of Interoceptive Awareness, the Toronto Alexithymia Scale, and the Emotion Regulation Skills Questionnaire. Depression and anxiety scores served as confounding variables. RESULTS: Fibromyalgia sufferers reported a stronger tendency to note as well as to avoid (unpleasant) body sensations. IS and psychopathology each explained about thirty percent of the variance in emotion regulation in fibromyalgia sufferers. Alexithymia was related to IS and emotion regulation in controls but not in fibromyalgia sufferers. CONCLUSION: Disturbances in interoception could be seen as the starting point of emotional difficulties in people with fibromyalgia. Following the fear-avoidance-model, experiential avoidance may restrict patients' ability to adaptively regulate emotional states, possibly initiating a vicious cycle of psychological distress and pain.


Assuntos
Sintomas Afetivos/psicologia , Regulação Emocional/fisiologia , Emoções/fisiologia , Fibromialgia/psicologia , Interocepção/fisiologia , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Nano Lett ; 19(11): 8207-8215, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31565946

RESUMO

Protein-surface interactions play a pivotal role in processes as diverse as biomineralization, biofouling, and the cellular response to medical implants. In biomineralization processes, biomacromolecules control mineral deposition and architecture via complex and often unknown mechanisms. For studying these mechanisms, the formation of magnetite nanoparticles in magnetotactic bacteria has become an excellent model system. Most interestingly, nanoparticle morphologies have been discovered that defy crystallographic rules (e.g., in the species Desulfamplus magnetovallimortis strain BW-1). In certain conditions, this strain mineralizes bullet-shaped magnetite nanoparticles, which exhibit defined (111) crystal faces and are elongated along the [100] direction. We hypothesize that surface-specific protein interactions break the nanoparticle symmetry, inhibiting the growth of certain crystal faces and thereby favoring the growth of others. Screening the genome of BW-1, we identified Mad10 (Magnetosome-associated deep-branching) as a potential magnetite-binding protein. Using atomic force microscope (AFM)-based single-molecule force spectroscopy, we show that a Mad10-derived peptide, which represents the most conserved region of Mad10, binds strongly to (100)- and (111)-oriented single-crystalline magnetite thin films. The peptide-magnetite interaction is thus material- but not crystal-face-specific. It is characterized by broad rupture force distributions that do not depend on the retraction speed of the AFM cantilever. To account for these experimental findings, we introduce a three-state model that incorporates fast rebinding. The model suggests that the peptide-surface interaction is strong in the absence of load, which is a direct result of this fast rebinding process. Overall, our study sheds light on the kinetic nature of peptide-surface interactions and introduces a new magnetite-binding peptide with potential use as a functional coating for magnetite nanoparticles in biotechnological and biomedical applications.


Assuntos
Proteínas de Bactérias/metabolismo , Deltaproteobacteria/metabolismo , Óxido Ferroso-Férrico/metabolismo , Magnetossomos/metabolismo , Peptídeos/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Biomineralização , Deltaproteobacteria/química , Deltaproteobacteria/ultraestrutura , Óxido Ferroso-Férrico/química , Magnetossomos/química , Magnetossomos/ultraestrutura , Peptídeos/química
7.
J Psychosom Res ; 181: 111655, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38609776

RESUMO

OBJECTIVE: (Cardiac) interoception was long considered a key mechanism behind symptom perception in persistent somatic symptoms (PSS). In this study, we aimed to extend earlier findings to clarify this potential interoceptive mechanisms of PSS. METHODS: A cross-sectional sample of 251 participants (23.1% with self-reported functional somatic syndrome) completed a laboratory study with two cardioceptive accuracy tasks (Schandry task and a new cardiac signal detection task) and multiple questionnaires. Somatic symptom distress and associated constructs were assessed with the PHQ-15, as well as with a novel multidimensional questionnaire measure (HiTOP-SF1) derived from the somatoform spectrum of the Hierarchical Taxonomy of Psychopathology (HiTOP). Correlations (frequentist and Bayesian) and structural equation modelling (SEM) helped further investigate the interplay between these variables. RESULTS: There were no significant correlations between measures of interoception and somatic symptom distress. Self-report and behavioral cardioceptive accuracy measures did not correlate significantly. No significant covariances emerged between diagnostic tools and cardioceptive accuracy; Bayesian analyses supported the lack of association between interoception and symptom perception. CONCLUSIONS: Cardiac interoception (specifically cardioceptive accuracy) unlikely represents a key mechanism in PSS etiology. We recommend investigating other factors in PSS.


Assuntos
Interocepção , Sintomas Inexplicáveis , Humanos , Feminino , Masculino , Interocepção/fisiologia , Adulto , Estudos Transversais , Pessoa de Meia-Idade , Transtornos Somatoformes/diagnóstico , Transtornos Somatoformes/psicologia , Inquéritos e Questionários , Teorema de Bayes , Autorrelato , Adulto Jovem
8.
Comput Struct Biotechnol J ; 25: 105-126, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38974014

RESUMO

The adoption of innovative advanced materials holds vast potential, contingent upon addressing safety and sustainability concerns. The European Commission advocates the integration of Safe and Sustainable by Design (SSbD) principles early in the innovation process to streamline market introduction and mitigate costs. Within this framework, encompassing ecological, social, and economic factors is paramount. The NanoSafety Cluster (NSC) delineates key safety and sustainability areas, pinpointing unresolved issues and research gaps to steer the development of safe(r) materials. Leveraging FAIR data management and integration, alongside the alignment of regulatory aspects, fosters informed decision-making and innovation. Integrating circularity and sustainability mandates clear guidance, ensuring responsible innovation at every stage. Collaboration among stakeholders, anticipation of regulatory demands, and a commitment to sustainability are pivotal for translating SSbD into tangible advancements. Harmonizing standards and test guidelines, along with regulatory preparedness through an exchange platform, is imperative for governance and market readiness. By adhering to these principles, the effective and sustainable deployment of innovative materials can be realized, propelling positive transformation and societal acceptance.

9.
Brain ; 135(Pt 4): 1128-40, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22434215

RESUMO

Patients with Parkinson's disease suffer from significant motor impairments and accompanying cognitive and affective dysfunction due to progressive disturbances of basal ganglia-cortical gating loops. Parkinson's disease has a long presymptomatic stage, which indicates a substantial capacity of the human brain to compensate for dopaminergic nerve degeneration before clinical manifestation of the disease. Neuroimaging studies provide evidence that increased motor-related cortical activity can compensate for progressive dopaminergic nerve degeneration in carriers of a single mutant Parkin or PINK1 gene, who show a mild but significant reduction of dopamine metabolism in the basal ganglia in the complete absence of clinical motor signs. However, it is currently unknown whether similar compensatory mechanisms are effective in non-motor basal ganglia-cortical gating loops. Here, we ask whether asymptomatic Parkin mutation carriers show altered patterns of brain activity during processing of facial gestures, and whether this might compensate for latent facial emotion recognition deficits. Current theories in social neuroscience assume that execution and perception of facial gestures are linked by a special class of visuomotor neurons ('mirror neurons') in the ventrolateral premotor cortex/pars opercularis of the inferior frontal gyrus (Brodmann area 44/6). We hypothesized that asymptomatic Parkin mutation carriers would show increased activity in this area during processing of affective facial gestures, replicating the compensatory motor effects that have previously been observed in these individuals. Additionally, Parkin mutation carriers might show altered activity in other basal ganglia-cortical gating loops. Eight asymptomatic heterozygous Parkin mutation carriers and eight matched controls underwent functional magnetic resonance imaging and a subsequent facial emotion recognition task. As predicted, Parkin mutation carriers showed significantly stronger activity in the right ventrolateral premotor cortex during execution and perception of affective facial gestures than healthy controls. Furthermore, Parkin mutation carriers showed a slightly reduced ability to recognize facial emotions that was least severe in individuals who showed the strongest increase of ventrolateral premotor activity. In addition, Parkin mutation carriers showed a significantly weaker than normal increase of activity in the left lateral orbitofrontal cortex (inferior frontal gyrus pars orbitalis, Brodmann area 47), which was unrelated to facial emotion recognition ability. These findings are consistent with the hypothesis that compensatory activity in the ventrolateral premotor cortex during processing of affective facial gestures can reduce impairments in facial emotion recognition in subclinical Parkin mutation carriers. A breakdown of this compensatory mechanism might lead to the impairment of facial expressivity and facial emotion recognition observed in manifest Parkinson's disease.


Assuntos
Face , Expressão Facial , Mutação/genética , Doença de Parkinson/genética , Doença de Parkinson/fisiopatologia , Ubiquitina-Proteína Ligases/genética , Adulto , Alelos , Análise de Variância , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Estudos de Casos e Controles , Função Executiva , Saúde da Família , Feminino , Fluordesoxiglucose F18/farmacocinética , Lateralidade Funcional/genética , Humanos , Processamento de Imagem Assistida por Computador , Levodopa/farmacocinética , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Oxigênio , Doença de Parkinson/diagnóstico por imagem , Reconhecimento Visual de Modelos , Estimulação Luminosa , Tomografia por Emissão de Pósitrons , Reconhecimento Psicológico/fisiologia , Autorrelato , Índice de Gravidade de Doença
10.
PLoS One ; 17(8): e0271717, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35980959

RESUMO

Somatic symptom disorder, illness anxiety disorder, and functional syndromes are characterized by burdensome preoccupation with somatic symptoms. Etiological models propose either increased interoceptive accuracy through hypervigilance to the body, or decreased and biased interoception through top-down predictions about sensory events. This systematic review and meta-analysis summarizes findings of 68 studies examining interoceptive accuracy and 8 studies examining response biases in clinical or non-clinical groups. Analyses yielded a medium population effect size for decreased interoceptive accuracy in functional syndromes, but no observable effect in somatic symptom disorder and illness anxiety disorder. The overall effect size was highly heterogeneous. Regarding response bias, there was a small significant effect in somatic symptom disorder and illness anxiety disorder. Our findings strengthen the notion of top-down factors that result in biased rather than accurate perception of body signals in somatic symptom disorder and illness anxiety disorder.


Assuntos
Interocepção , Sintomas Inexplicáveis , Ansiedade , Transtornos de Ansiedade , Viés , Humanos , Hipocondríase , Interocepção/fisiologia , Síndrome
11.
Clin Psychol Eur ; 4(4): e5615, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36762347

RESUMO

Background and Objectives: Comorbidity between major depressive disorder (MDD) and alcohol use disorder (AUD) is highly prevalent but reasons for this association are unclear. Rumination may activate metacognitive beliefs that contribute to the development and maintenance of rumination and depression. Negative metacognitions can further lead to other dysfunctional coping strategies (i.e., consumption of alcohol). We examined whether alcohol reduces (state) metacognitions, rumination and other disorder-specific processes in a group of individuals suffering from MDD. Method: In an experiment with three randomized conditions we investigated whether the consumption of alcohol, placebo or no alcohol (orange juice) affects (meta-)cognitions, depressive symptoms and / or psychophysiological variables while participants ruminate. Results: Voluntary rumination increased self-reported sadness, tension and rumination, tensed facial muscles and increased heart rate, but did not affect (state) metacognitions and heart rate variability. The consumption of alcohol did not influence rumination, metacognitions, depressive or psychophysiological measures. Limitations: We recruited a depressed population but excluded pathological alcohol use due to ethical considerations. Conclusions: We found no evidence that alcohol consumption affects rumination, metacognitions and other disorder-specific processes in MDD. However, rumination had a negative effect on various depression-specific processes, although it did not activate (negative state) metacognitions.

12.
Physiol Behav ; 254: 113904, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35820627

RESUMO

Emotion theories emphasize the relevance of (predicted) bodily changes for the construction of one's own emotions and an extensive overlap of brain regions involved during emotion intensity perception and somatosensory processing. The ability to accurately perceive bodily changes and its impact on the perception of emotion intensity has been studied for at least 40 years. The results of previous studies were summarized in a meta-analysis to examine how closely interoceptive accuracy and emotion intensity are related. After a systematic literature search, 4036 studies were screened for eligibility. Only studies assessing adults from general population samples were considered. Samples recruited to examine mental disorders or neurological conditions were excluded. Thirty studies with a quantifiable measure for the relation of interoceptive accuracy and emotion intensity perception were included in the meta-analysis. Interoceptive accuracy was significantly related with emotion intensity perception, when emotions were experimentally induced (k= 22, r= 0.15). However, the relationship was only found when IAPS images (k= 9, r= 0.33) or facial expressions (k= 3, r= 0.24) were used for emotion induction. No significant relation was found in studies without emotion induction (k= 19, r = -0.007). There was considerable bias, varying dependent on bias assessment method, study protocol and examined risk of bias dimension. We discuss the impact of differences in study protocols, review the operationalization of interoceptive accuracy critically and derive directions for future research.


Assuntos
Interocepção , Adulto , Emoções , Expressão Facial , Frequência Cardíaca , Humanos
13.
Psychol Assess ; 33(8): 705-715, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33829843

RESUMO

Interoception is essential for the maintenance of physical and mental health. Paradigms assessing cardioceptive accuracy do not separate sensitivity from bias or are very demanding. We present the piloting (study 1; N = 60) and psychometric evaluation and validation (study 2; N = 84) of a novel task for the assessment of cardiac interoceptive perception following the principles of signal detection theory. By disentangling sensitivity and response bias, we demonstrate that the previously used interoceptive accuracy score of the heartbeat mental tracking task represents an amalgam of sensitivity and response bias. The new task demonstrated adequate test-retest reliabilities for sensitivity (d') and response bias (c). Sensitivity was inversely related (ß = -.36) to somatic symptom distress after statistically controlling for response bias. The novel cardiovascular signal detection task is easy to implement, feasible, and promising in terms of unraveling the role of (cardiac) interoceptive perception in psychopathology. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Frequência Cardíaca , Interocepção , Distúrbios Somatossensoriais , Humanos , Projetos Piloto , Psicometria , Reprodutibilidade dos Testes , Distúrbios Somatossensoriais/diagnóstico , Distúrbios Somatossensoriais/psicologia
14.
Biol Psychol ; 165: 108166, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34389438

RESUMO

Interoception may play an important role for emotion regulation and stress, thereby affecting mental health in children and adults. Yet, little is known on interoception in preschool children. Therefore, we investigated interoceptive accuracy using the adapted Jumping Jack Paradigm (JJP) and its relationship with emotion regulation and stress. In Study I, 40 preschoolers completed the JJP and an emotion regulation task, demonstrating a positive relationship between interoceptive accuracy and emotion regulation at trend level (R² = 0.231, p = .023; ß = .278, p = .073). In Study II, 31 preschoolers completed the adapted JJP before and after an acute laboratory stress test. Higher total cortisol output following acute stress induction was associated with reduced interoceptive accuracy (r = -0.670, p = .017). Extending earlier findings in adults and school-children, the relationship of interoceptive accuracy with emotion regulation and stress highlights the importance to investigate interoception in early childhood.


Assuntos
Regulação Emocional , Interocepção , Adaptação Fisiológica , Adulto , Conscientização , Criança , Pré-Escolar , Frequência Cardíaca , Humanos , Resolução de Problemas
15.
Nanoscale ; 13(48): 20396-20400, 2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34860229

RESUMO

Magnetite-binding proteins are in high demand for the functionalization of magnetic nanoparticles. Binding analysis of six previously uncharacterized proteins from the magnetotactic Deltaproteobacterium Desulfamplus magnetovallimortis BW-1 identified two new magnetite-binding proteins (Mad10, Mad11). These proteins can be utilized as affinity tags for the immobilization of recombinant fusion proteins to magnetite.


Assuntos
Deltaproteobacteria , Nanopartículas de Magnetita , Magnetossomos , Magnetospirillum , Proteínas de Bactérias/metabolismo , Proteínas de Transporte , Deltaproteobacteria/metabolismo , Óxido Ferroso-Férrico/metabolismo , Magnetossomos/metabolismo , Magnetospirillum/metabolismo
16.
J Mech Behav Biomed Mater ; 111: 103991, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32823075

RESUMO

Chitons are herbivorous invertebrates that use rows of ultrahard magnetite-based teeth connected to a flexible belt (radula) to rasp away algal deposits growing on and within rocky outcrops along coastlines around the world. Each tooth is attached to the radula by an organic structure (stylus) that provides mechanical support during feeding. However, the underlying structures within the stylus, and their subsequent function within the chiton have yet to be investigated. Here, we investigate the macrostructural architecture, the regional material and elemental distribution and subsequent nano-mechanical properties of the stylus from the Northern Pacific dwelling Cryptochiton stelleri. Using a combination of µ-CT imaging, optical and electron microscopy, as well as elemental analysis, we reveal that the stylus is a highly contoured tube, mainly composed of alpha-chitin fibers, with a complex density distribution. Nanoindentation reveals regiospecific and graded mechanical properties that can be correlated with both the elemental composition and material distribution. Finite element modeling shows that the unique macroscale architecture, material distribution and elemental gradients have been optimized to preserve the structural stability of this flexible, yet robust functionally-graded fiber-reinforced composite tube, providing effective function during rasping. Understanding these complex fiber-based structures offers promising blueprints for lightweight, multifunctional and integrated materials.


Assuntos
Poliplacóforos , Dente , Animais , Óxido Ferroso-Férrico , Microscopia Eletrônica
17.
J Behav Ther Exp Psychiatry ; 63: 12-20, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30557753

RESUMO

BACKGROUND AND OBJECTIVES: Deviations in interoception might contribute to the development and maintenance of mental disorders. The improvement of interoceptive accuracy (IA) is desirable but assessment and training methods remain controversial. For instance, it was assumed that performance increases in heartbeat counting paradigms after cardiac feedback were due to an improvement of knowledge with regard to heart rate rather than due to an actual improvement in IA. METHODS: Here, we examined effects of contingent cardiac feedback training, non-contingent cardiac feedback, mindfulness practice, and a waiting period with external attentional focus on IA. 100 healthy participants underwent a mental tracking paradigm before and after 20 min of training or waiting. RESULTS: Results revealed a significant increase of IA in the contingent feedback condition (d = 1.21, p ≤ .001) and no significant changes after non-contingent feedback, mindfulness practice or waiting (d ≤ 0.37; p ≥ .06). Furthermore, IA increase was significantly higher after the contingent feedback training compared to all other conditions, including non-contingent feedback. LIMITATIONS: Future studies need to replicate these findings in clinical samples and examine time dependent effects. CONCLUSIONS: The results provide evidence for the trainability of heartbeat perception. IA improvements may reduce the symptom burden in people suffering from mental disorders and psychophysiological conditions that have been linked to lower interoceptive accuracy such as depression, somatic symptom disorder, chronic pain, and functional somatic syndromes. Consequently, exploration of biofeedback training procedures shall be continued with the aim of identifying relevant mediators of beneficial effects and future implementation in clinical practice.


Assuntos
Biorretroalimentação Psicológica/métodos , Voluntários Saudáveis/psicologia , Interocepção , Atenção Plena , Pulso Arterial/psicologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
18.
Inform Health Soc Care ; 43(4): 427-442, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29045164

RESUMO

The concept of electronic health (eHealth) literacy evolved from the social and information sciences and describes competencies necessary to use electronic health services. As it is a rather new topic, and as there is no current overview of the state of the art in research, it is not possible to identify research gaps. Therefore, the objective of this viewpoint article is to increase knowledge on the current state of the art of research in eHealth literacy and to identify gaps in scientific research which should be focused on by the research community in the future. The article provides a current viewpoint of the concept of eHealth literacy and related research. Gaps can be found in terms of a missing "gold standard" regarding both the definition and the measurement of eHealth literacy. Furthermore, there is a need for identifying the implications on eHealth developers, which evolve from the measurement of eHealth literacy in eHealth users. Finally, a stronger inclusion of health professionals, both in the evolving concept and in the measurement of eHealth literacy, is needed in the future.


Assuntos
Letramento em Saúde/métodos , Pesquisa/organização & administração , Telemedicina/métodos , Alfabetização Digital , Humanos , Alfabetização , Projetos de Pesquisa , Terminologia como Assunto
19.
Neuropsychologia ; 100: 26-34, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28392302

RESUMO

Self-evaluation affects one's own mental state, social interactions and everyday life. Mood, in turn, has an impact on self-evaluation. However, the influence of mood on self-evaluation at the neural level has barely been examined. In this fMRI study, the interaction of mood and self-perception was investigated in 20 healthy participants. Happy, sad and neutral music was presented while participants were instructed to immerse themselves in the mood of the music and to rate how well presented traits characterized themselves. In a lexical control condition, subjects had to count a specific letter in the word. Behavioral data reflected successful mood induction. While self-ascription of positive traits was unaffected by mood, self-ascription of negative characteristics was decreased by negative affect. A positive correlation was found between self-worth scores and the difference in the amount of self-ascribed positive versus negative traits during negative mood induction. At the neural level, amygdalo-hippocampal, superior and middle temporal structures were differently involved in self-evaluation (vs. lexical processing) depending on the mood. While activation of the amygdalo-hippocampal complex was found during sad in comparison to both happy and neutral mood, superior/middle temporal gyrus (STG/MTG) activation was only found when contrasting sad vs. neutral mood. Further, a correlation analysis with self-worth ratings revealed a positive relation to STG activation during self-ascription of trait adjectives in sad compared to neutral mood. Our results underscore the importance of the current emotional state for self-evaluation and identify some neural correlates of this effect. Our findings in healthy research participants suggest a compensatory mechanism during sad mood induction to maintain a positive self-image, which is supported by activation of limbic and fronto-temporal cortex. Studies in clinically depressed populations could reveal whether this compensatory mechanism is aberrant.


Assuntos
Afeto/fisiologia , Mapeamento Encefálico , Encéfalo/fisiologia , Emoções/fisiologia , Música , Autoimagem , Estimulação Acústica , Adulto , Análise de Variância , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue , Escalas de Graduação Psiquiátrica , Autoavaliação (Psicologia) , Adulto Jovem
20.
Front Neurol ; 8: 682, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29326646

RESUMO

BACKGROUND: Affective dysfunctions are common in patients with Parkinson's disease, but the underlying neurobiological deviations have rarely been examined. Parkinson's disease is characterized by a loss of dopamine neurons in the substantia nigra resulting in impairment of motor and non-motor basal ganglia-cortical loops. Concerning emotional deficits, some studies provide evidence for altered brain processing in limbic- and lateral-orbitofrontal gating loops. In a second line of evidence, human premotor and inferior parietal homologs of mirror neuron areas were involved in processing and understanding of emotional facial expressions. We examined deviations in brain activation during processing of facial expressions in patients and related these to emotion recognition accuracy. METHODS: 13 patients and 13 healthy controls underwent an emotion recognition task and a functional magnetic resonance imaging (fMRI) measurement. In the Emotion Hexagon test, participants were presented with blends of two emotions and had to indicate which emotion best described the presented picture. Blended pictures with three levels of difficulty were included. During fMRI scanning, participants observed video clips depicting emotional, non-emotional, and neutral facial expressions or were asked to produce these facial expressions themselves. RESULTS: Patients performed slightly worse in the emotion recognition task, but only when judging the most ambiguous facial expressions. Both groups activated inferior frontal and anterior inferior parietal homologs of mirror neuron areas during observation and execution of the emotional facial expressions. During observation, responses in the pars opercularis of the right inferior frontal gyrus, in the bilateral inferior parietal lobule and in the bilateral supplementary motor cortex were decreased in patients. Furthermore, in patients, activation of the right anterior inferior parietal lobule was positively related to accuracy in the emotion recognition task. CONCLUSION: Our data provide evidence for a contribution of human homologs of monkey mirror areas to the emotion recognition deficit in Parkinson's disease.

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