51 |
Mid-adolescent neurocognitive development of ignoring and attending emotional stimuliVetter, Nora C., Pilhatsch, Maximilian, Weigelt, Sarah, Ripke, Stephan, Smolka, Michael N. 04 January 2016 (has links) (PDF)
Appropriate reactions toward emotional stimuli depend on the distribution of prefrontal attentional resources. In mid-adolescence, prefrontal top-down control systems are less engaged, while subcortical bottom-up emotional systems are more engaged. We used functional magnetic resonance imaging to follow the neural development of attentional distribution, i.e. attending versus ignoring emotional stimuli, in adolescence. 144 healthy adolescents were studied longitudinally at age 14 and 16 while performing a perceptual discrimination task. Participants viewed two pairs of stimuli – one emotional, one abstract – and reported on one pair whether the items were the same or different, while ignoring the other pair. Hence, two experimental conditions were created: "attending emotion/ignoring abstract" and "ignoring emotion/attending abstract". Emotional valence varied between negative, positive, and neutral. Across conditions, reaction times and error rates decreased and activation in the anterior cingulate and inferior frontal gyrus increased from age 14 to 16. In contrast, subcortical regions showed no developmental effect. Activation of the anterior insula increased across ages for attending positive and ignoring negative emotions. Results suggest an ongoing development of prefrontal top-down resources elicited by emotional attention from age 14 to 16 while activity of subcortical regions representing bottom-up processing remains stable.
|
52 |
Discovering relations between indirectly connected biomedical conceptsTsatsaronis, George, Weissenborn, Dirk, Schroeder, Michael 04 January 2016 (has links) (PDF)
BACKGROUND:
The complexity and scale of the knowledge in the biomedical domain has motivated research work towards mining heterogeneous data from both structured and unstructured knowledge bases. Towards this direction, it is necessary to combine facts in order to formulate hypotheses or draw conclusions about the domain concepts. This work addresses this problem by using indirect knowledge connecting two concepts in a knowledge graph to discover hidden relations between them. The graph represents concepts as vertices and relations as edges, stemming from structured (ontologies) and unstructured (textual) data. In this graph, path patterns, i.e. sequences of relations, are mined using distant supervision that potentially characterize a biomedical relation.
RESULTS:
It is possible to identify characteristic path patterns of biomedical relations from this representation using machine learning. For experimental evaluation two frequent biomedical relations, namely \"has target\", and \"may treat\", are chosen. Results suggest that relation discovery using indirect knowledge is possible, with an AUC that can reach up to 0.8, a result which is a great improvement compared to the random classification, and which shows that good predictions can be prioritized by following the suggested approach.
CONCLUSIONS:
Analysis of the results indicates that the models can successfully learn expressive path patterns for the examined relations. Furthermore, this work demonstrates that the constructed graph allows for the easy integration of heterogeneous information and discovery of indirect connections between biomedical concepts.
|
53 |
Development of Eimeria nieschulzi (Coccidia, Apicomplexa) Gamonts and Oocysts in Primary Fetal Rat CellsChen, Hong, Wiedmer, Stefanie, Hanig, Sacha, Entzeroth, Rolf, Kurth, Michael 22 January 2014 (has links) (PDF)
The in vitro production of gametocytes and oocysts of the apicomplexan parasite genus Eimeria is still a challenge in coccidiosis research. Until today, an in vitro development of gametocytes or oocysts had only been shown in some Eimeria species. For several mammalian Eimeria species, partial developments could be achieved in different cell types, but a development up to gametocytes or oocysts is still lacking. This study compares several permanent cell lines with primary fetal cells of the black rat (Rattus norvegicus) concerning the qualitative in vitro development of the rat parasite Eimeria nieschulzi. With the help of transgenic parasites, the developmental progress was documented. The selected Eimeria nieschulzi strain constitutively expresses the yellow fluorescent protein and a macrogamont specific upregulated red tandem dimer tomato. In the majority of all investigated host cells the development stopped at the second merozoite stage. In a mixed culture of cells derived from inner fetal organs the development of schizont generations I-IV, macrogamonts, and oocysts were observed in crypt-like organoid structures. Microgamonts and microgametes could not be observed and oocysts did not sporulate under air supply. By immunohistology, we could confirm that wild-type E. nieschulzi stages can be found in the crypts of the small intestine. The results of this study may be helpful for characterization of native host cells and for development of an in vitro cultivation system for Eimeria species.
|
54 |
Glycosaminoglycan Monosaccharide Blocks Analysis by Quantum Mechanics, Molecular Dynamics, and Nuclear Magnetic ResonanceSamsonov, Sergey A., Theisgen, Stephan, Riemer, Thomas, Huster, Daniel, Pisabarro, M. Teresa 09 July 2014 (has links) (PDF)
Glycosaminoglycans (GAGs) play an important role in many biological processes in the extracellular matrix. In a theoretical approach, structures of monosaccharide building blocks of natural GAGs and their sulfated derivatives were optimized by a B3LYP6311ppdd//B3LYP/ 6-31+G(d) method. The dependence of the observed conformational properties on the applied methodology is described. NMR chemical shifts and proton-proton spin-spin coupling constants were calculated using the GIAO approach and analyzed in terms of the method's accuracy and sensitivity towards the influence of sulfation, O1-methylation, conformations of sugar ring, and ω dihedral angle. The net sulfation of the monosaccharides was found to be correlated with the 1H chemical shifts in the methyl group of the N-acetylated saccharides both theoretically and experimentally. The ω dihedral angle conformation populations of free monosaccharides and monosaccharide blocks within polymeric GAG molecules were calculated by a molecular dynamics approach using the GLYCAM06 force field and compared with the available NMR and quantum mechanical data. Qualitative trends for the impact of sulfation and ring conformation on the chemical shifts and proton-proton spin-spin coupling constants were obtained and discussed in terms of the potential and limitations of the computational methodology used to be complementary to NMR experiments and to assist in experimental data assignment.
|
55 |
The role of psychosocial working conditions on burnout and its core component emotional exhaustion – a systematic reviewSeidler, Andreas, Thinschmidt, Marleen, Deckert, Stefanie, Then, Francisca, Hegewald, Janice, Nieuwenhuijsen, Karen, Riedel-Helle, Steffi G. 14 July 2014 (has links) (PDF)
Aims: To analyze the association between psychosocial working conditions and burnout and its core component emotional exhaustion, a systematic literature review was undertaken including cohort studies, case–control studies, and randomized controlled trials.
Methods: The literature search in Medline and PsycInfo was based on a defined search string and strict exclusion and inclusion criteria. Evaluation of the 5,599 initially identified search hits by two independent reviewers and a detailed quality assessment resulted in six methodologically adequate cohort studies considering the relationship between psychosocial working conditions and burnout (one study) as well as the burnout core component emotional exhaustion (five studies).
Results: The results of our systematic review point to a relationship between psychosocial working conditions and the development of emotional exhaustion/burnout. Particularly high job demands seem to play a role in the development of emotional exhaustion. However, strong intercorrelations between workplace factors, as a matter of principle, make the identification of a single psychosocial workplace factor (being associated with an especially high or low risk of burnout) difficult.
Conclusions: Multidimensional approaches including reduction of work demands, enhancement of decision latitude and improving the social climate might be promising for preventing burnout and emotional exhaustion. However, methodologically adequate intervention studies are urgently needed to prove the effectiveness of workplace interventions.
|
56 |
Participant adherence to the Internet-based prevention program StudentBodies™ for eating disorders — A reviewBeintner, Ina, Jacobi, Corinna, Taylor, C. Barr 14 July 2014 (has links) (PDF)
Study and treatment dropout and adherence represent particular challenges in studies on Internet-based interventions. However, systematic investigations of the relationship between study, intervention and patient characteristics, participation, and intervention outcomes in online-prevention are scarce. A review of participation in trials investigating a cognitive-behavioral, Internet-based, 8-week prevention program (StudentBodies™) for eating disorders, moderators of participation, and the impact of participation on the relationship of outcome moderators and outcomes was performed. Seven US and three German studies with a total of N = 1059 female participants were included. Two of the U.S. and one of the German trials explicitly addressed high risk samples in a selective prevention approach. Across studies, dropout rates ranged from 3% to 26%. The women who participated in the trials accessed on average between 49% and 83% of the assigned intervention content. None of the study characteristics (universal vs. selective prevention, incentives, country, participants' age) predicted adherence or study dropout. After adjusting for adherence, intervention outcomes (EDI Drive for Thinness and EDI Bulimia) were only moderated by participant's age, with smaller effects in one sample of adolescent girls. Adherence to StudentBodies™ proved to be high across a number of trials, settings and countries. These findings are promising, but it is likely that adherence will be distinctly lower in the general public than in research settings, and intervention effects will turn out smaller. However, the intervention is readily available at minimal cost per participant, and the public health impact may still be notable.
|
57 |
Comprehensive histological evaluation of bone implantsRentsch, Claudia, Schneiders, Wolfgang, Manthey, Suzanne, Rentsch, Barbe, Rammelt, Stefan 14 July 2014 (has links) (PDF)
To investigate and assess bone regeneration in sheep in combination with new implant materials classical histological staining methods as well as immunohistochemistry may provide additional information to standard radiographs or computer tomography. Available published data of bone defect regenerations in sheep often present none or sparely labeled histological images. Repeatedly, the exact location of the sample remains unclear, detail enlargements are missing and the labeling of different tissues or cells is absent. The aim of this article is to present an overview of sample preparation, staining methods and their benefits as well as a detailed histological description of bone regeneration in the sheep tibia. General histological staining methods like hematoxylin and eosin, Masson-Goldner trichrome, Movat’s pentachrome and alcian blue were used to define new bone formation within a sheep tibia critical size defect containing a polycaprolactone-co-lactide (PCL) scaffold implanted for 3 months (n = 4). Special attention was drawn to describe the bone healing patterns down to cell level. Additionally one histological quantification method and immunohistochemical staining methods are described.
|
58 |
Positioning of term infants during delivery room routine handling – analysis of videosKonstantelos, Dimitrios, Gurth, Heidrun, Bergert, Renate, Ifflaender, Sascha, Rüdiger, Mario 07 July 2014 (has links) (PDF)
Background: Delivery room management (DR) of the newly born infant should be performed according to international guidelines, but no recommendations are available for an infant’s position immediately after birth. The present study was performed to answer the following questions: 1. How often is DR-management performed in term infants in side position? 2. Is routine DR-management possible in side position? 3. Is there any benefit of side position with respect to agitation or vital parameters? Methods: Cross-sectional study of video-recorded DR-management in term newborns delivered by C-section in 2012. Videos were analysed for infant’s position, administered interventions, vital parameters and agitation. Results: 187 videos were analysed. The Main Position (defined as position spent more than 70% of the time) was “supine” in 91, “side” in 63 and “not determinable” in 33 infants. “Supine” infants received significantly (p < 0.001) more often stimulation (12.5% of the total time) than “side” infants (3.9% of time). There were no differences between both groups with regard to suctioning; CPAP was exclusively (98%) administered in supine position. Newborns on side were less agitated than those on supine. There was a trend towards a better oxygenation in “side” positioned infants (p = 0.055) and significantly (p = 0.04) higher saturation values in “left-sided” infants than “right-sided” infants at 8th minute. “Side” positioned infants reached oxygen saturation values >90% earlier than “supine” positioned infants (p = 0.16). Conclusions: DR-management is feasible in the side position in term infants. Side position seems to be associated with reduced agitation and improved oxygenation. However, it remains unclear whether this represents a causal relationship or an association. The study supports the need for a randomized controlled trial.
|
59 |
Physical Properties of Polyamide-12 versus PMMA Denture Base MaterialWieckiewicz, Mieszko, Opitz, Volker, Richter, Gert, Böning, Klaus W. 07 July 2014 (has links) (PDF)
Objectives. Polyamide-12 (PA) is a flexible material suited for denture bases and clasping. This study investigated its potential aging effects with a focus on surface roughness, color stability, and elasticity. Methods. PA specimens (Valplast) of 40 × 10 × 2mm and equally measuring PMMA specimens (Palapress) as control were fabricated. Color changes after storage in air, water, coffee, and red wine (n = 10) were measured using the CIE L*a*b color specification. Elasticity after thermocycling (1000, 3000, and 7000 cycles, n = 15) was measured by three-point bending testing. Mean surface roughness (Ra) was determined after storage in the liquids mentioned above and thermocycling (n = 10). Results. Tukey’s HSD test (P < 0.05) revealed statistically significant color changes of PA in red wine (ΔE = 4.27 after 12 days, EΔE = 6.90 after 12 days) and coffee (ΔE = 3.93 after 36 days) but no color changes in PMMA. Elastic modulus of PA was 845MPa and not affected by thermocycling (Tukey’s HSD test, P > 0.81). Dry specimens showed significantly decreased elasticity (P < 0.001). Mean surface roughness (PA 0.20 μm, PMMA 0.28 μm) did not change significantly after thermocycling or storage (Mann-Whitney U-test, 0.16 < P < 0.65). Significance. PA exhibited a higher susceptibility to discoloration than PMMA. Neither surface roughness nor elasticity of PA was altered by artificial aging.
|
60 |
Phenotypic Variability in a Family with Aicardi-Goutières Syndrome Due to the Common A177T RNASEH2B MutationTüngler, Victoria, Schmidt, Franziska, Hieronimus, Steve, Reyes-Velasco, Claudio, Lee-Kirsch, Min Ae 09 July 2014 (has links) (PDF)
Aicardi-Goutières syndrome (AGS) is a rare inflammatory encephalopathy mimicking in utero acquired viral infection. Cardinal findings comprise leukodystrophy, basal ganglia calcifications and cerebral atrophy along with cerebrospinal fluid lymphocytosis and elevated interferon-α. In the majority of cases AGS is inherited as an autosomal recessive trait and caused by mutations in six genes including RNASEH2A, RNASEH2B, RNASEH2C, TREX1, SAMHD1 and ADAR1, all of which encode enzymes acting on nucleic acid species. Most patients present with first neurological signs in early infancy and experience severe global developmental delay. Here, we report on the unusual divergent phenotype of two siblings who both carry the most frequent AGS causing p.A177T (c.529G > A) RNASEH2B mutation in the homozygous state. While one sibling showed a typical AGS presentation with early onset and severe statomotor and mental impairment, the older sibling was intellectually completely normal. She was only diagnosed because of mild spasticity of the legs and serological signs of autoimmunity. These findings highlight the phenotypic variability of AGS and suggest that AGS may be underdiagnosed among children with mild cerebral palsy.
|
Page generated in 0.0773 seconds