Plasmonic Gold Helices for the visible range fabricated by oxygen plasma purification of electron beam induced deposits

Electron beam induced deposition (EBID) currently provides the only direct writing technique for truly three-dimensional nanostructures with geometrical features below 50 nm. Unfortunately, the depositions from metal-organic precursors suffer from a substantial carbon content. This hinders many applications, especially in plasmonics where the metallic nature of the geometric surfaces is mandatory. To overcome this problem a post-deposition treatment with oxygen plasma at room temperature was investigated for the purification of gold containing EBID structures. Upon plasma treatment, the structures experience a shrinkage in diameter of about 18 nm but entirely keep their initial shape. The proposed purification step results in a core-shell structure with the core consisting of mainly unaffected EBID material and a gold shell of about 20 nm in thickness. These purified structures are plasmonically active in the visible wavelength range as shown by dark field optical microscopy on helical nanostructures. Most notably, electromagnetic modeling of the corresponding scattering spectra verified that the thickness and quality of the resulting gold shell ensures an optical response equal to that of pure gold nanostructures

Dose-dependent changes in real-life affective well-being in healthy community-based individuals with mild to moderate childhood trauma exposure

Background Childhood trauma exposures (CTEs) are frequent, well-established risk factor for the development of psychopathology. However, knowledge of the effects of CTEs in healthy individuals in a real life context, which is crucial for early detection and prevention of mental disorders, is incomplete. Here, we use ecological momentary assessment (EMA) to investigate CTE load-dependent changes in daily-life affective well-being and psychosocial risk profile in n = 351 healthy, clinically asymptomatic, adults from the community with mild to moderate CTE. Findings EMA revealed significant CTE dose-dependent decreases in real-life affective valence (p = 0.007), energetic arousal (p = 0.032) and calmness (p = 0.044). Psychosocial questionnaires revealed a broad CTE-related psychosocial risk profile with dose-dependent increases in mental health risk-associated features (e.g., trait anxiety, maladaptive coping, loneliness, daily hassles; p values < 0.003) and a corresponding decrease in factors protective for mental health (e.g., life satisfaction, adaptive coping, optimism, social support; p values < 0.021). These results were not influenced by age, sex, socioeconomic status or education. Conclusions Healthy community-based adults with mild to moderate CTE exhibit dose-dependent changes in well-being manifesting in decreases in affective valence, calmness and energy in real life settings, as well as a range of established psychosocial risk features associated with mental health risk. This indicates an approach to early detection, early intervention, and prevention of CTE-associated psychiatric disorders in this at-risk population, using ecological momentary interventions (EMI) in real life, which enhance established protective factors for mental health, such as green space exposure, or social support

Reduced Real-life Affective Well-being and Amygdala Habituation in Unmedicated Community Individuals at Risk for Depression and Anxiety

Background: Early identification of risk for depression and anxiety disorders is important for prevention, but real-life affective well-being and its biological underpinnings in the population remain understudied. Here, we combined methods from epidemiology, psychology, ecological momentary assessment, and functional magnetic resonance imaging to study real-life and neural affective functions in individuals with subclinical anxiety and depression from a population-based cohort of young adults. Methods: We examined psychological measures, real-life affective valence, functional magnetic resonance imaging amygdala habituation to negative affective stimuli, and the relevance of neural readouts for daily-life affective function in 132 non–help-seeking community individuals. We compared psychological and ecological momentary assessment measures of 61 unmedicated individuals at clinical risk for depression and anxiety (operationalized as subthreshold depression and anxiety symptoms or a former mood or anxiety disorder) with those of 48 nonrisk individuals and 23 persons with a mood or anxiety disorder. We studied risk-associated functional magnetic resonance imaging signals in subsamples with balanced sociodemographic and image quality parameters (26 nonrisk, 26 at-risk persons). Results: Compared with nonrisk persons, at-risk individuals showed significantly decreased real-life affective valence (p = .038), reduced amygdala habituation (familywise error–corrected p = .024, region of interest corrected), and an intermediate psychological risk profile. Amygdala habituation predicted real-life affective valence in control subjects but not in participants at risk (familywise error–corrected p = .005, region of interest corrected). Conclusions: Our data suggest real-life and neural markers for affective alterations in unmedicated community individuals at risk for depression and anxiety and highlight the significance of amygdala habituation measures for the momentary affective experience in real-world environments

Initial response to the COVID-19 pandemic on real-life well-being, social contact and roaming behavior in patients with schizophrenia, major depression and healthy controls: A longitudinal ecological momentary assessment study

The COVID-19 pandemic strongly impacted people\u27s daily lives. However, it remains unknown how the pandemic situation affects daily-life experiences of individuals with preexisting severe mental illnesses (SMI). In this real-life longitudinal study, the acute onset of the COVID-19 pandemic in Germany did not cause the already low everyday well-being of patients with schizophrenia (SZ) or major depression (MDD) to decrease further. On the contrary, healthy participants’ well-being, anxiety, social isolation, and mobility worsened, especially in healthy individuals at risk for mental disorder, but remained above the levels seen in patients. Despite being stressful for healthy individuals at risk for mental disorder, the COVID-19 pandemic had little additional influence on daily-life well-being in psychiatric patients with SMI. This highlights the need for preventive action and targeted support of this vulnerable population

Influence of ketamine on brain structure and function - investigations in healthy volunteers using pharmacological MRI

In den letzten Jahren hat sich Ketamin zunehmend als möglicher Prototyp einer neuen Klasse schnell wirksamer antidepressiver Substanzen erwiesen, welche nicht über monoaminerge Transmittersysteme, sondern durch Modulation des glutamatergen Systems wirken. Aufgrund der Relevanz, sowohl für Depression als auch für Schizophrenie, wurden sowohl präklinische als auch klinische Studien durchgeführt, um die neurobiologischen Korrelate von Ketamin zu untersuchen. Ergebnisse dieser Untersuchungen lassen auf eine Modulation struktureller und neurofunktioneller Parameter schließen. Ziel der Dissertation war es unter Anwendung von pharmakologischer Magnetresonanztomographie (MRT) zusätzliche Daten über kurzfristige Effekte von Ketamin auf die Hirnstruktur und -funktion zu erhalten. Zu diesem Zweck wurde eine doppel-blinde, randomisierte, plazebo-kontrollierte, crossover Studie durchgeführt um Ketamin-spezifische Veränderungen der grauen Substanz, der neuronalen Aktivierung und der funktionellen Konnektivität zu ermitteln. Jede Studienteilnehmerin/jeder Studienteilnehmer unterzog sich 2 MRT-Sitzungen mit einem zeitlichen Abstand von etwa 1 Woche. Dabei wurde je nach Randomisierung bei der ersten Sitzung Ketamin und bei der zweiten Placebo verabreicht oder umgekehrt. Es erfolgte die Infusion einer an das Körpergewicht angepassten Dosis von Ketamin bzw. Plazebo mittels eines MR-kompatiblen automatischen Infusionssystems während eines 55-minuten langen Ruhescans; unmittelbar vor und nach Infusion wurden strukturelle T1-gewichte MRT-Bilder angefertigt. In der ersten Studie konnten wir eine signifikante Veränderung der Thalamus-Funktion durch Ketamingabe im Vergleich zu Placebo zeigen, genauer beschrieben eine Verstärkung der funktionellen Konnektivität des somatosensorischen und temporalen Kortex zum Thalamus, sowie des Netzwerk-Knoten des Thalamus. In der zweiten Studie zeigte sich eine Steigerung der neuronalen Aktivierung im mittleren zingulären Kortex, der Insula beidseits und dem Thalamus unter Ketamingabe im Vergleich zu Plazebo. Im Gegensatz dazu führte die Ketamingabe im Bereich des subgenualen Teils und Area subcallosa des anterioren zingulären Kortex, dem orbitofrontalen Kortex, sowie dem Gyrus rectus zu einer signifikanten Abnahme der Aktivierung. In der dritten Studie konnten wir keine unmittelbare Veränderung des Signals der grauen Substanz durch Ketamingabe nachweisen. Interessanterweise zeigte sich sowohl in der Ketamin-, als auch der Plazebobedingung eine signifikante Reduktion des T1-Signals im Vergleich vor und nach Infusion welches möglicherweise auf die Beeinflussung des MRT Signals durch substanzunabhängige, unspezifische Faktoren zurückzuführen ist. Zusammenfassend zeigte sich in der durchgeführten Studie ein substantieller Effekt von Ketamin auf funktioneller Aktivierungs- und Netzwerkebene. Die Hirnareale, in denen diese Veränderungen auftraten, wurden sowohl mit Depression als auch mit Schizophrenie in Verbindung gebracht. Daher liefern die vorliegenden Daten weitere Informationen zu den neurobiologischen Korrelaten der antidepressiven Wirkung von Ketamin und zeigen, dass die kurzfristigen Effekte von Ketamin auf neurofunktioneller Ebene zum Teil jenen gleichen, welche für Schizophrenie beschrieben wurden.In the last years ketamine has emerged as a prototype of a new class of rapid antidepressant agents, acting not via the monoaminergic transmitter systems but via modulation of the glutamatergic system and the NMDA receptor. Thus, intense scientific effort has been put in the characterization of its clinical and neurobiological properties. Previous studies have shown a significant impact of ketamine on a microstructural and a neurofunctional level in animals and humans. It was therefore the aim of the thesis to provide new insights into short-term effects of ketamine using pharmacological Magnetic Resonance Imaging (MRI). A double-blind, randomized, placebo-controlled, crossover study was performed to determine the effects of ketamine on grey matter signal, neuronal activation and functional connectivity. Each participant underwent 2 MRI sessions with an interval of approximately 1 week, receiving ketamine at the first session and placebo at the second or vice versa, according to randomization. Infusion of a body-weight adjusted dosage of ketamine and placebo was performed using a MRI-compatible fully-automated infusion system during a 55-min resting-state functional MRI scan, structural T1-weighted scans were carried out before and after infusion. In the first study we could show a significant impact of ketamine on thalamus function, more precisely increased cortico-thalamic connectivity of the somatosensory and temporal cortex and the thalamus hub network. In the second study we showed increases of neural activation in the midcingulate cortex, the dorsal part of the anterior cingulate cortex, the insula bilaterally, and the thalamus in the ketamine condition compared to placebo. Additionally, we found a significant decrease of activation in a cluster within the subgenual/subcallosal part of the anterior cingulate cortex, the orbitofrontal cortex and the gyrus rectus. In the third study we could not show short-term changes of ketamine on grey matter volume. However, significant decrease of grey matter signal both in the placebo and the ketamine condition over time were found, possibly due to drug-unspecific confounders of the T1-signal. Overall this study paints the picture of a strong impact of ketamine on a functional activation and network level. The implicated brain regions are relevant both for antidepressant treatment and schizophrenia. These results add further information about possible mechanisms underlying the antidepressant effects of ketamine and also shows that ketamine-induced neurofunctional changes partly resemble those reported in schizophrenia, adding evidence to the “ketamine model of schizophrenia”.submitted by Anna HöflichAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersMedizinische Universität Wien, Dissertation, 2017OeBB(VLID)257145

How the social robot Sophia is mediated by a YouTube video

In robotics, a field of research still populated by prototypes, much of the research is made through videos and pictures of robots. We study how the highly human-like robot Sophia is perceived through a YouTube video. Often researchers take for granted in their experiments that people perceive humanoids as such. With this study we wanted to understand to what extent a convenience sample of university students perceive Sophia’s human-likeness; second, we investigated which mental capabilities and emotions they attribute to her; and third, we explored the possible uses of Sophia they imagine. Our findings suggest that the morphological human-likeness of Sophia, through the video, is not salient in the Sophia’s representations of these participants. Only some mental functions are attributed to Sophia and no emotions. Finally, uses of Sophia turned out to be connected to the gender stereotypes that characterize stereotyped women’s professions and occupations but not completely

Circuit Mechanisms of Reward, Anhedonia, and Depression

Pleasure and motivation are important factors for goal-directed behavior and well-being in both animals and humans. Intact hedonic capacity requires an undisturbed interplay between a number of different brain regions and transmitter systems. Concordantly, dysfunction of networks encoding for reward have been shown in depression and other psychiatric disorders. The development of technological possibilities to investigate connectivity on a functional level in humans and to directly influence networks in animals using optogenetics among other techniques has provided new important insights in this field of research. In this review, we aim to provide an overview on the neurobiological substrates of anhedonia on a network level. For this purpose, definition of anhedonia and the involved reward components are described first, then current data on reward networks in healthy individuals and in depressed patients are summarized, and the roles of different neurotransmitter systems involved in reward processing are specified. Based on this information, the impact of different therapeutic approaches on reward processing is described with a particular focus on deep brain stimulation (DBS) as a possibility for a direct modulation of human brain structures in vivo. Overall, results of current studies emphasize the importance of anhedonia in psychiatric disorders and the relevance of targeting this phenotype for a successful psychiatric treatment. However, more data incorporating these results for the refinement of methodological approaches are needed to be able to develop individually tailored therapeutic concepts based on both clinical and neurobiological profiles of patients.(VLID)458401

Increased neural habituation in the amygdala and orbitofrontal cortex in social anxiety disorder revealed by FMRI.

A characterizing symptom of social anxiety disorder (SAD) is increased emotional reactivity towards potential social threat in combination with impaired emotion and stress regulation. While several neuroimaging studies have linked SAD with hyperreactivity in limbic brain regions when exposed to emotional faces, little is known about habituation in both the amygdala and neocortical regulation areas. 15 untreated SAD patients and 15 age- and gender-matched healthy controls underwent functional magnetic resonance imaging during repeated blocks of facial emotion ([Formula: see text]) and object discrimination tasks ([Formula: see text]). Emotion processing networks were defined by a task-related contrast ([Formula: see text]). Linear regression was employed for assessing habituation effects in these regions. In both groups, the employed paradigm robustly activated the emotion processing and regulation network, including the amygdalae and orbitofrontal cortex (OFC). Statistically significant habituation effects were found in the amygdalae, OFC, and pulvinar thalamus of SAD patients. No such habituation was found in healthy controls. Concurrent habituation in the medial OFC and the amygdalae of SAD patients as shown in this study suggests intact functional integrity and successful short-term down-regulation of neural activation in brain areas responsible for emotion processing. Initial hyperactivation may be explained by an insufficient habituation to new stimuli during the first seconds of exposure. In addition, our results highlight the relevance of the orbitofrontal cortex in social anxiety disorders

Disrupted Effective Connectivity Between the Amygdala and Orbitofrontal Cortex in Social Anxiety Disorder During Emotion Discrimination Revealed by Dynamic Causal Modeling for fMRI

Photograph of daffodils in Woodward Park