Die Entwicklung regionaler Netzwerke Sozialer Landwirtschaft in Bayern

This paper deals with the establishment and advancement of Social Farming networks in Bavaria. The scientific research of the thesis is based on literature research, the participation in network meetings and as a main point 14 guideline-based interviews. First of all the main motivations and aims of network participants will be described. Thereafter past, present and possible future steps of the three networks in Bavaria will be presented. The final discussion provides assistance, also to other networks, by presenting key success factors of the Bavarian networking activities

Entwicklung und Charakterisierung eines 3D-druckbaren und elektrisch leitfähigen Hydrogels für die Geweberegeneration

Biomaterials development for tissue regeneration increasingly evolves in the direction of more functional and stimuli response materials. Such materials should allow to monitor, influence, and to control tissue healing processes to a higher extent than conventional biomaterials. Hydrogels, which refer to water-swollen polymer networks, can mimic the natural extracellular matrix environment while offering the possibility to be rendered electrically conductive to increase their degree of functionality. However, engineering electroconductive and cytocompatible hydrogels that can be processed into complex shapes which mimic the in vivo tissue architecture still remains a key challenge in tissue engineering. In this doctoral thesis, a three-dimensionally (3D) printable, electroconductive, and cytocompatible hydrogel has been developed. The material is based on oxidized alginate, gelatin, and conjugated polypyrrole polymer. Possible routes to engineer such electroactive and 3D-printable hydrogel are reviewed, with the goal to identify a fabrication approach that achieves hierarchically ordered hydrogels with electrical functionality. The 3D-printability of an oxidized alginate gelatin hydrogel is optimized by investigating the modification of gelatin to improve its properties for bioprinting. A crosslinking route to study and adjust the degradation and mechanical properties of the hydrogel is explored. Enzymatic crosslinking of gelatin is mediated by microbial transglutaminase and combined with ionic crosslinking of alginate to result in a dual crosslinking approach of the oxidized alginate-gelatin system. In a final study, the optimized hydrogel is modified using electroconductive polypyrrole polymer to achieve an electrically functional hydrogel material. This study demonstrated that it is possible to create 3D-printable and electroconductive hydrogels with tuneable degradation and mechanical properties. The hydrogels facilitate cell adhesion and are cytocompatible toward multiple cell types, such as fibroblasts, endothelial cells, and mouse teratocarcinoma cells. 3D bioprinting allows to create hierarchically ordered oxidized alginate-gelatin structures with macro- and micro-porosity and a height of up to five millimeters, enabling thus the development of relatively complex scaffolds that mimic the multilayered architecture found in native tissues. In summary, the hydrogels developed and characterized in this thesis are of value for future research in tissue engineering exploring electrical or mechanical stimulation to influence cellular behavior. The materials may be applied as stimuli transmissive biomaterials in several approaches relevant for tissue engineering. In addition, the novel hydrogels are useful to investigate the effect of electrical conductivity as a biomaterial property to regulate cell response in an extracellular-matrix-like environment.Die Entwicklung von Biomaterialien für die Geweberegeneration entwickelt sich zunehmend in Richtung funktionellerer und stimuli-responsiver Materialien. Solche Materialien sollen es ermöglichen, Gewebeheilungsprozesse in höherem Maße zu überwachen, zu beeinflussen und zu kontrollieren als herkömmliche Biomaterialien. Hydrogele, die sich auf wassergequollene Polymernetzwerke beziehen, können die natürliche Umgebung der extrazellulären Matrix nachahmen und bieten gleichzeitig die Möglichkeit, elektrisch leitfähig gemacht zu werden, um ihre Funktionalität zu erhöhen. Die Entwicklung von elektrisch leitfähigen und zytokompatiblen Hydrogelen, die zu komplexen Formen verarbeitet werden können, welche in vivo Gewebearchitektur nachahmen, bleibt jedoch eine Schlüsselherausforderung im Tissue Engineering. In dieser Doktorarbeit wurde ein dreidimensional (3D) druckbares, elektrisch leitfähiges und zytokompatibles Hydrogel entwickelt. Das Material basiert auf oxidiertem Alginat, Gelatine und konjugiertem Polypyrrol Polymer. Mögliche Wege zur Entwicklung eines solchen elektroaktiven und 3D-druckbaren Hydrogels werden überprüft, mit dem Ziel, einen Herstellungsansatz zu identifizieren, der hierarchisch geordnete Hydrogele mit elektrischer Funktionalität erreicht. Die 3D Druckfähigkeit eines oxidierten Alginat-Gelatine-Hydrogels wird optimiert, indem die Modifizierung von Gelatine untersucht wird, um ihre Eigenschaften für den Biodruck zu verbessern. Ein Vernetzungsweg zur Einstellung des Abbaus und der mechanischen Eigenschaften des Hydrogels wird untersucht. Die enzymatische Vernetzung von Gelatine wird durch mikrobielle Transglutaminase vermittelt und mit der ionischen Vernetzung von Alginat kombiniert, um zu einem dualen Vernetzungsansatz des oxidierten Alginat-Gelatine-Systems zu führen. In einer abschließenden Studie wird das optimierte Hydrogel mit elektrisch leitfähigem Polypyrrol Polymer modifiziert, um ein elektrisch funktionelles HydrogelMaterial zu erhalten. Diese Studie zeigte, dass es möglich ist, 3D-druckbare und elektrisch leitfähige Hydrogele mit einstellbaren abbau- und mechanischen Eigenschaften herzustellen. Die Hydrogele ermöglichen die Zelladhäsion und sind zytokompatibel gegenüber mehreren Zelltypen, wie Fibroblasten, Endothelzellen und Maus-Teratokarzinomzellen. Der 3D-Biodruck ermöglicht es, hierarchisch geordnete oxidierte Alginat-GelatineStrukturen mit Makro- und Mikroporosität und einer Höhe von bis zu fünf Millimetern zu erzeugen, was die Entwicklung relativ komplexer Gerüste ermöglicht, die die vielschichtige Architektur nativer Gewebe nachahmen. Zusammenfassend sind die in dieser Dissertation entwickelten und charakterisierten Hydrogele von Wert für die zukünftige Forschung im Tissue Engineering, die elektrische oder mechanische Stimulation zur Beeinflussung des Zellverhaltens erforscht. Die Materialien können als stimulitransmissive Biomaterialien in verschiedenen Ansätzen verwendet werden, die für das Tissue Engineering relevant sind. Darüber hinaus sind die neuartigen Hydrogele nützlich, um die Wirkung der elektrischen Leitfähigkeit als Biomaterialeigenschaft zu untersuchen, um die Zellantwort in einer extrazellulären Matrix-ähnlichen Umgebung zu regulieren

Cells of the synovium in rheumatoid arthritis. Synovial fibroblasts

For some time synovial fibroblasts have been regarded simply as innocent synovial cells, mainly responsible for synovial homeostasis. During the past decade, however, a body of evidence has accumulated illustrating that rheumatoid arthritis synovial fibroblasts (RASFs) are active drivers of joint destruction in rheumatoid arthritis. Details regarding the intracellular signalling cascades that result in long-term activation and synthesis of proinflammatory molecules and matrix-degrading enzymes by RASFs have been analyzed. Molecular, cellular and animal studies have identified various interactions with other synovial and inflammatory cells. This expanded knowledge of the distinct role played by RASFs in the pathophysiology of rheumatoid arthritis has moved these fascinating cells to the fore, and work to identify targeted therapies to inhibit their joint destructive potential is underway

HowDirty: an R package to evaluate molecular contaminants in LC-MS experiments

Contaminants derived from consumables, reagents, and sample handling often negatively affect LC-MS data acquisition. In proteomics experiments, they can markedly reduce identification performance, reproducibility, and quantitative robustness. Here, we introduce a data analysis workflow combining MS1 feature extraction in Skyline with HowDirty, an R-markdown-based tool, that automatically generates an interactive report on the molecular contaminant level in LC-MS data sets. To facilitate the interpretation of the results, the HTML report is self-contained and self-explanatory, including plots that can be easily interpreted. The R package HowDirty is available from https://github.com/DavidGZ1/HowDirty. To demonstrate a showcase scenario for the application of HowDirty, we assessed the impact of ultrafiltration units from different providers on sample purity after filter-assisted sample preparation (FASP) digestion. This allowed us to select the filter units with the lowest contamination risk. Notably, the filter units with the lowest contaminant levels showed higher reproducibility regarding the number of peptides and proteins identified. Overall, HowDirty enables the efficient evaluation of sample quality covering a wide range of common contaminant groups that typically impair LC-MS analyses, facilitating corrective or preventive actions to minimize instrument downtime

Towards c=0 Flows

We discuss some implications of the gravitational dressing of the renormalization group for conformal field theories perturbed by relevant operators. The renormalization group flows are defined with respect to the dilatation operator associated with the $J_0^{(0)}$ mode of the $SL(2,R)$ affine algebra. We discuss the possibility of passing under the $c=25$ barrier along renormalization group flows in some models.Comment: LaTex file, 11 pages, QMW Preprint, QMW 94-2

3D Printing of Piezoelectric Barium Titanate-Hydroxyapatite Scaffolds with Interconnected Porosity for Bone Tissue Engineering

The prevalence of large bone defects is still a major problem in surgical clinics. It is, thus, not a surprise that bone-related research, especially in the field of bone tissue engineering, is a major issue in medical research. Researchers worldwide are searching for the missing link in engineering bone graft materials that mimic bones, and foster osteogenesis and bone remodeling. One approach is the combination of additive manufacturing technology with smart and additionally electrically active biomaterials. In this study, we performed a three-dimensional (3D) printing process to fabricate piezoelectric, porous barium titanate (BaTiO3) and hydroxyapatite (HA) composite scaffolds. The printed scaffolds indicate good cytocompatibility and cell attachment as well as bone mimicking piezoelectric properties with a piezoelectric constant of 3 pC/N. This work represents a promising first approach to creating an implant material with improved bone regenerating potential, in combination with an interconnected porous network and a microporosity, known to enhance bone growth and vascularization

The impact of slice-reduced computed tomography on histogram-based densitometry assessment of lung fibrosis in patients with systemic sclerosis

Background To evaluate usability of slice-reduced sequential computed tomography (CT) compared to standard high-resolution CT (HRCT) in patients with systemic sclerosis (SSc) for qualitative and quantitative assessment of interstitial lung disease (ILD) with respect to (I) detection of lung parenchymal abnormalities, (II) qualitative and semiquantitative visual assessment, (III) quantification of ILD by histograms and (IV) accuracy for the 20%-cut off discrimination. Methods From standard chest HRCT of 60 SSc patients sequential 9-slice-computed tomography (reduced HRCT) was retrospectively reconstructed. ILD was assessed by visual scoring and quantitative histogram parameters. Results from standard and reduced HRCT were compared using non-parametric tests and analysed by univariate linear regression analyses. Results With respect to the detection of parenchymal abnormalities, only the detection of intrapulmonary bronchiectasis was significantly lower in reduced HRCT compared to standard HRCT (P=0.039). No differences were found comparing visual scores for fibrosis severity and extension from standard and reduced HRCT (P=0.051-0.073). All scores correlated significantly (P<0.001) to histogram parameters derived from both, standard and reduced HRCT. Significant higher values of kurtosis and skewness for reduced HRCT were found (both P<0.001). In contrast to standard HRCT histogram parameters from reduced HRCT showed significant discrimination at cut-off 20% fibrosis (sensitivity 88% kurtosis and skewness; specificity 81% kurtosis and 86% skewness; cut-off kurtosis ≤26, cut-off skewness ≤4; both P<0.001). Conclusions Reduced HRCT is a robust method to assess lung fibrosis in SSc with minimal radiation dose with no difference in scoring assessment of lung fibrosis severity and extension in comparison to standard HRCT. In contrast to standard HRCT histogram parameters derived from the approach of reduced HRCT could discriminate at a threshold of 20% lung fibrosis with high sensitivity and specificity. Hence it might be used to detect early disease progression of lung fibrosis in context of monitoring and treatment of SSc patients

Miniaturized differential scanning calorimeter with an integrated mass sensing system: first steps

In this paper, the first steps towards integrating a mass sensing system into an existing miniaturized ceramic DSC (differential scanning calorimetry) chip are presented. A vibration setup is developed based on the mass-dependent change in frequency of the DSC chip as an oscillating cantilever. A simulation model reveals that the resolution of the measurement can be improved by reducing the chip thickness. In this study, different measurement methods (acoustic, optical, and piezoresistive) are investigated. Three complete measurement systems are set up and evaluated with regard to their integration in the DSC chip. All presented measurement methods show promising results and already allow mass measurements with a resolution of 100 µg.</p

The RMS Charge Radius of the Proton and Zemach Moments

On the basis of recent precise measurements of the electric form factor of the proton, the Zemach moments, needed as input parameters for the determination of the proton rms radius from the measurement of the Lamb shift in muonic hydrogen, are calculated. It turns out that the new moments give an uncertainty as large as the presently stated error of the recent Lamb shift measurement of Pohl et al.. De Rujula's idea of a large Zemach moment in order to reconcile the five standard deviation discrepancy between the muonic Lamb shift determination and the result of electronic experiments is shown to be in clear contradiction with experiment. Alternative explanations are touched upon.Comment: 6 pages, 4 figures, final version includes discussion of systematic and numerical error