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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

An Alkali Activated Binder for High Chemical Resistant Self-Leveling Mortar

Funke, Henrik L., Gelbrich, Sandra, Kroll, Lothar 13 October 2016 (has links) (PDF)
This paper reports the development of an Alkali Activated Binder (AAB) with an emphasis on the performance and the durability of the AAB-matrix. For the development of the matrix, the reactive components granulated slag and coal fly ash were used, which were alkali activated with a mixture of sodium hydroxide (2 - 10 mol/l) and aqueous sodium silicate solution (SiO2/Na2O molar ratio: 2.1) at ambient temperature. A sodium hydroxide concentration of 5.5 mol/l revealed the best compromise between setting time and mechanical strengths of the AAB. With this sodium hydroxide concentration, the compressive and the 3-point bending tensile strength of the hardened AAB were 53.4 and 5.5 MPa respectively after 14 days. As a result of the investigation of the acid resistance, the AAB-matrix showed a very high acid resistance in comparison to ordinary Portland cement concrete. In addition, the AAB had a high frost resistance, which had been validated by the capillary suction, internal damage and freeze thaw test with a relative dynamic E-Modulus of 93% and a total amount of scaled material of 30 g/m2 after 28 freeze-thaw cycles (exposure class: XF3).
82

Senior Dance Experience, Cognitive Performance, and Brain Volume in Older Women

Niemann, Claudia, Godde, Ben, Voelcker-Rehage, Claudia 13 October 2016 (has links) (PDF)
Physical activity is positively related to cognitive functioning and brain volume in older adults. Interestingly, different types of physical activity vary in their effects on cognition and on the brain. For example, dancing has become an interesting topic in aging research, as it is a popular leisure activity among older adults, involving cardiovascular and motor fitness dimensions that can be positively related to cognition. However, studies on brain structure are missing. In this study, we tested the association of long-term senior dance experience with cognitive performance and gray matter brain volume in older women aged 65 to 82 years. We compared nonprofessional senior dancers (n=28) with nonsedentary control group participants without any dancing experience (n=29), who were similar in age, education, IQ score, lifestyle and health factors, and fitness level. Differences neither in the four tested cognitive domains (executive control, perceptual speed, episodic memory, and long-term memory) nor in brain volume (VBM whole-brain analysis, region-of-interest analysis of the hippocampus) were observed. Results indicate that moderate dancing activity (1-2 times per week, on average) has no additional effects on gray matter volume and cognitive functioning when a certain lifestyle or physical activity and fitness level are reached.
83

Plantar sensory vibration thresholds are not influenced by body position

Germano, Andresa M.C., Schmidt, Daniel, Schlee, Günther, Milani, Thomas L. 25 October 2016 (has links) (PDF)
Monitoring skin sensitivity is studied to clarify its relationship on balance. Measuring skin sensitivity is performed when subjects are sitting or lying, whereas balance tests are measured during standing. However, afferent signal processing and subsequent efferent responses can be altered by different body positions. Therefore, this study investigated whether vibration perception thresholds (VPTs) are influenced by body positions. Sixty-six healthy subjects (41♀; 25♂) participated in this study. Five measurements of VPTs were performed at each of the three analyzed anatomical locations (heel, first metatarsal head, hallux) of the right plantar foot under two randomized conditions: during sitting and standing. The contact force applied to the probe was measured and controlled within the five trials. Contact forces between the probe and the foot were higher during standing. However, no differences in VPTs were found between conditions. This indicates that VPTs are not different during standing compared to sitting, contrary to our expectations. We conclude that higher forces did not induce increased receptor activity. Since no differences were found between thresholds, future clinical studies can implement plantar VPT tests during sitting in association with balance tests during standing.
84

Exercise-induced changes in basal ganglia volume and their relation to cognitive performance

Becker, Linda, Kutz, D. F., Voelcker-Rehage, Claudia 14 November 2016 (has links) (PDF)
Physical activity, especially cardiovascular fitness training, has been shown to enhance cognitive performance and to counteract age-related cognitive decline1-5. Furthermore, regular physical activity has been demonstrated to diminish age-related volume-shrinkage in several brain regions particularly in the prefrontal cortex and hippocampus6-10. In the same vein, physical activity and high levels of cardiovascular fitness seem to enhance neurocognition during childhood11-13. In this context, the basal ganglia and its components, the caudate nucleus, the putamen and the globus pallidus, are of special interest as animal research indicates that exercise also seems to influence the molecular architecture and the metabolic capacity of the basal ganglia14,15. Besides their fundamental role in motor execution16, the basal ganglia are also involved in many cognitive functions like mental flexibility17, task-switching ability18 and cognitive control19. Furthermore, age-related disorders like Parkinson’s disease are related to a decline in the dopamine circuits of the basal ganglia20,21. The striatum is the input nucleus of the basal ganglia and is composed of caudate nucleus and putamen. The pars interna of the globus pallidus is (together with the substantia nigra pars reticulata) the output region of the basal ganglia and conveys information from the striatum to the thalamus and back to the frontal areas22. The striatum, which is essential for cognitive flexibility and attentional control, shows an increase during childhood and adolescence23,24 and a particularly rapid and early age-related change9,25 in older adults. Furthermore, the described cognitive functions are essential for academic success of children and young adults. Thus, it is of particular interest to find appropriate interventions that could mitigate both the volume-shrinkage and the (presumably) related cognitive decline in older adults and/or that could support academic success in children. In this review, we will summarize research that investigated whether physical activity has the potential to be such an intervention. First, we will show that neuroplasticity in the basal ganglia is possible in principle. Second, we will report studies where the relationship between physical fitness level and volume of the basal ganglia and its relation to cognitive performance were investigated. Besides cross-sectional studies, we will report studies that investigated exercise-induced changes in the volume of the basal ganglia and related changes in cognitive performance after long-term fitness interventions.
85

Fingolimod in a patient with heart failure on the background of pulmonary arterial hypertension and coronary artery disease

Thomas, Katja, Schrötter, Hagen, Halank, Michael, Ziemssen, Tjalf 18 May 2015 (has links) (PDF)
Background: Fingolimod is the first oral immunomodulatory therapy approved for highly active relapsing remitting multiple sclerosis. Based on the distribution pattern of fingolimod interacting sphingosine-1-phosphat receptors in organism including immune system and cardiovascular system clinical monitoring of patients and evaluation of adverse events are recommended. Despite extensive data on cardiovascular safety, experience with fingolimod in patients with concomitant cardiological disease, especially within the pulmonary circulation, is rare. Case presentation: We report the case of a 46-year-old woman presented with relapsing remitting multiple sclerosis and severe idiopathic pulmonary arterial hypertension. Fingolimod was initiated because of disease activity of multiple sclerosis with two relapses and gadolinium-enhancing lesions in MRI. The patient demonstrated stable disease course of idiopathic pulmonary arterial hypertension when fingolimod was started. Fingolimod therapy did not alter or even worsen the pulmonary or cardiovascular conditions during first dose application as well as follow up of nine months. Conclusion: In this report, we present the first case of fingolimod treatment in a patient with highly active multiple sclerosis and severe idiopathic pulmonary arterial hypertension. We suggest an interdisciplinary approach with detailed cardiopulmonary monitoring for safety in such patients.
86

Antibody response to Mycoplasma pneumoniae: protection of host and influence on outbreaks?

Dumke, Roger, Jacobs, Enno 10 January 2017 (has links) (PDF)
In humans of all ages, the cell wall-less and genome-reduced species Mycoplasma pneumoniae can cause infections of the upper and lower respiratory tract. The well-documented occurrence of major peaks in the incidence of community-acquired pneumonia cases reported world-wide, the multifaceted clinical manifestations of infection and the increasing number of resistant strains provide reasons for ongoing interest in the pathogenesis of mycoplasmal disease. The results of recent studies have provided insights into the interaction of the limited virulence factors of the bacterium with its host. In addition, the availability of complete M. pneumoniae genomes from patient isolates and the development of proteomic methods for investigation of mycoplasmas have not only allowed characterization of sequence divergences between strains but have also shown the importance of proteins and protein parts for induction of the immune reaction after infection. This review focuses on selected aspects of the humoral host immune response as a factor that might influence the clinical course of infections, subsequent protection in cases of re-infections and changes of epidemiological pattern of infections. The characterization of antibodies directed to defined antigens and approaches to promote their induction in the respiratory mucosa are also preconditions for the development of a vaccine to protect risk populations from severe disease due to M. pneumoniae.
87

Randomized controlled trials - a matter of design

Spieth, Peter Markus, Kubasch, Anne Sophie, Penzlin, Ana Isabel, Illigens, Ben Min-Woo, Barlinn, Kristian, Siepmann, Timo 06 January 2017 (has links) (PDF)
Randomized controlled trials (RCTs) are the hallmark of evidence-based medicine and form the basis for translating research data into clinical practice. This review summarizes commonly applied designs and quality indicators of RCTs to provide guidance in interpreting and critically evaluating clinical research data. It further reflects on the principle of equipoise and its practical applicability to clinical science with an emphasis on critical care and neurological research. We performed a review of educational material, review articles, methodological studies, and published clinical trials using the databases MEDLINE, PubMed, and ClinicalTrials.gov. The most relevant recommendations regarding design, conduction, and reporting of RCTs may include the following: 1) clinically relevant end points should be defined a priori, and an unbiased analysis and report of the study results should be warranted, 2) both significant and nonsignificant results should be objectively reported and published, 3) structured study design and performance as indicated in the Consolidated Standards of Reporting Trials statement should be employed as well as registration in a public trial database, 4) potential conflicts of interest and funding sources should be disclaimed in study report or publication, and 5) in the comparison of experimental treatment with standard care, preplanned interim analyses during an ongoing RCT can aid in maintaining clinical equipoise by assessing benefit, harm, or futility, thus allowing decision on continuation or termination of the trial.
88

High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability

Krause, Andreas, Dörfler, Susanne, Piwko, Markus, Wisser, Florian M., Jaumann, Tony, Ahrens, Eike, Giebeler, Lars, Althues, Holger, Schädlich, Stefan, Grothe, Julia, Jeffery, Andrea, Grube, Matthias, Brückner, Jan, Martin, Jan, Eckert, Jürgen, Kaskel, Stefan, Mikolajick, Thomas, Weber, Walter M. 25 January 2017 (has links) (PDF)
We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging.
89

Large-scale gene expression profiling data of bone marrow stromal cells from osteoarthritic donors

Stiehler, Maik, Rauh, Juliane, Bünger, Cody, Jacobi, Angela, Vater, Corina, Schildberg, Theresa, Liebers, Cornelia, Günther, Klaus-Peter, Bretschneider, Henriette 27 January 2017 (has links) (PDF)
This data article contains data related to the research article entitled, "in vitro characterization of bone marrow stromal cells from osteoarthritic donors" [1]. Osteoarthritis (OA) represents the main indication for total joint arthroplasty and is one of the most frequent degenerative joint disorders. However, the exact etiology of OA remains unknown. Bone marrow stromal cells (BMSCs) can be easily isolated from bone marrow aspirates and provide an excellent source of progenitor cells. The data shows the identification of pivotal genes and pathways involved in osteoarthritis by comparing gene expression patterns of BMSCs from osteoarthritic versus healthy donors using an array-based approach.
90

Microdialysis Sampling from Wound Fluids Enables Quantitative Assessment of Cytokines, Proteins, and Metabolites Reveals Bone Defect-Specific Molecular Profiles

Förster, Yvonne, Schmidt, Johannes R., Wissenbach, Dirk K., Pfeiffer, Susanne E. M., Baumann, Sven, Hofbauer, Lorenz C., von Bergen, Martin, Kalkhof, Stefan, Rammelt, Stefan 27 January 2017 (has links) (PDF)
Bone healing involves a variety of different cell types and biological processes. Although certain key molecules have been identified, the molecular interactions of the healing progress are not completely understood. Moreover, a clinical routine for predicting the quality of bone healing after a fracture in an early phase is missing. This is mainly due to a lack of techniques to comprehensively screen for cytokines, growth factors and metabolites at their local site of action. Since all soluble molecules of interest are present in the fracture hematoma, its in-depth assessment could reveal potential markers for the monitoring of bone healing. Here, we describe an approach for sampling and quantification of cytokines and metabolites by using microdialysis, combined with solid phase extractions of proteins from wound fluids. By using a control group with an isolated soft tissue wound, we could reveal several bone defect-specific molecular features. In bone defect dialysates the neutrophil chemoattractants CXCL1, CXCL2 and CXCL3 were quantified with either a higher or earlier response compared to dialysate from soft tissue wound. Moreover, by analyzing downstream adaptions of the cells on protein level and focusing on early immune response, several proteins involved in the immune cell migration and activity could be identified to be specific for the bone defect group, e.g. immune modulators, proteases and their corresponding inhibitors. Additionally, the metabolite screening revealed different profiles between the bone defect group and the control group. In summary, we identified potential biomarkers to indicate imbalanced healing progress on all levels of analysis.

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