Photochromic materials via sol-gel process

Powders and thin films of photochromic glasses containing AgBr or AgCl microcrystals were synthesized via sol-gel process. Up to 10 wt%, of Ag⁺, bonded with suitable complexing agents, were introduced into the matrix system consisting of xSiO₂-(1 - x)Al₂O₃ (x = 0.7... 1). After drying and heat treatment the AgX microcrystals (X = Cl, Br) were characterized by X-ray diffraction and high-resolution TEM. The photochromic properties were measured using a diode array UV-VIS spectrometer

Sol-gel derived coatings with completely reversible photochromism

Besides the photochromic glasses based on silver halides especially the cuprous halide containing materials are of practical importance. Due to their high absorption coefficient the cuprous halides are particularly suited for the preparation of thin photochromic films. Using the sol-gel technique silicon alkoxide based coating solutions with continuously distributed photoactive components were prepared. From these sols single or multilayer coatings were produced by dipping. The precipitation of the cuprous halide microcrystals as carriers of the photochromic properties of the coatings proceeded during a subsequent heat treatment (temperature range of 100 to 800 °C). Thus it was possible for the first time to produee photochromic coatings with a pronounced darkening and with complete reversibility of the photochromic reactions at room temperature

Dynamic flux balance modeling to increase the production of high-value compounds in green microalgae

Background Photosynthetic organisms can be used for renewable and sustainable production of fuels and high-value compounds from natural resources. Costs for design and operation of large-scale algae cultivation systems can be reduced if data from laboratory scale cultivations are combined with detailed mathematical models to evaluate and optimize the process. Results In this work we present a flexible modeling formulation for accumulation of high-value storage molecules in microalgae that provides quantitative predictions under various light and nutrient conditions. The modeling approach is based on dynamic flux balance analysis (DFBA) and includes regulatory models to predict the accumulation of pigment molecules. The accuracy of the model predictions is validated through independent experimental data followed by a subsequent model-based fed-batch optimization. In our experimentally validated fed-batch optimization study we increase biomass and β-carotene density by factors of about 2.5 and 2.1, respectively. Conclusions The analysis shows that a model-based approach can be used to develop and significantly improve biotechnological processes for biofuels and pigments

Theory of branching morphogenesis by local interactions and global guidance

Branching morphogenesis governs the formation of many organs such as lung, kidney, and the neurovascular system. Many studies have explored system-specific molecular and cellular regulatory mechanisms, as well as self-organizing rules underlying branching morphogenesis. However, in addition to local cues, branched tissue growth can also be influenced by global guidance. Here, we develop a theoretical framework for a stochastic self-organized branching process in the presence of external cues. Combining analytical theory with numerical simulations, we predict differential signatures of global vs. local regulatory mechanisms on the branching pattern, such as angle distributions, domain size, and space-filling efficiency. We find that branch alignment follows a generic scaling law determined by the strength of global guidance, while local interactions influence the tissue density but not its overall territory. Finally, using zebrafish innervation as a model system, we test these key features of the model experimentally. Our work thus provides quantitative predictions to disentangle the role of different types of cues in shaping branched structures across scales

Breathomics profiling of metabolic pathways affected by major depression: Possibilities and limitations

BackgroundMajor depressive disorder (MDD) is one of the most common psychiatric disorders with multifactorial etiologies. Metabolomics has recently emerged as a particularly potential quantitative tool that provides a multi-parametric signature specific to several mechanisms underlying the heterogeneous pathophysiology of MDD. The main purpose of the present study was to investigate possibilities and limitations of breath-based metabolomics, breathomics patterns to discriminate MDD patients from healthy controls (HCs) and identify the altered metabolic pathways in MDD.MethodsBreath samples were collected in Tedlar bags at awakening, 30 and 60 min after awakening from 26 patients with MDD and 25 HCs. The non-targeted breathomics analysis was carried out by proton transfer reaction mass spectrometry. The univariate analysis was first performed by T-test to rank potential biomarkers. The metabolomic pathway analysis and hierarchical clustering analysis (HCA) were performed to group the significant metabolites involved in the same metabolic pathways or networks. Moreover, a support vector machine (SVM) predictive model was built to identify the potential metabolites in the altered pathways and clusters. The accuracy of the SVM model was evaluated by receiver operating characteristics (ROC) analysis.ResultsA total of 23 differential exhaled breath metabolites were significantly altered in patients with MDD compared with HCs and mapped in five significant metabolic pathways including aminoacyl-tRNA biosynthesis (p = 0.0055), branched chain amino acids valine, leucine and isoleucine biosynthesis (p = 0.0060), glycolysis and gluconeogenesis (p = 0.0067), nicotinate and nicotinamide metabolism (p = 0.0213) and pyruvate metabolism (p = 0.0440). Moreover, the SVM predictive model showed that butylamine (p = 0.0005, pFDR=0.0006), 3-methylpyridine (p = 0.0002, pFDR = 0.0012), endogenous aliphatic ethanol isotope (p = 0.0073, pFDR = 0.0174), valeric acid (p = 0.005, pFDR = 0.0162) and isoprene (p = 0.038, pFDR = 0.045) were potential metabolites within identified clusters with HCA and altered pathways, and discriminated between patients with MDD and non-depressed ones with high sensitivity (0.88), specificity (0.96) and area under curve of ROC (0.96).ConclusionAccording to the results of this study, the non-targeted breathomics analysis with high-throughput sensitive analytical technologies coupled to advanced computational tools approaches offer completely new insights into peripheral biochemical changes in MDD

Update and prognosis of <i>Dermacentor</i> distribution in Germany: Nationwide occurrence of <i>Dermacentor reticulatus</i>.

A considerable range expansion of Dermacentor reticulatus has been observed in several European countries, which is concerning in the light of its vector function for several pathogens, including Babesia canis and tick-borne encephalitis virus (TBEV). The present study provides an update on the distribution of Dermacentor ticks in Germany, using a citizen science approach. Ticks were collected by citizens from March 2020 to May 2021, and submitted along with information on the date and location of collection, potential hosts and details about the circumstances of discovery. In total, 3,292 Dermacentor specimens were received, of which 76.4% (2,515/3,292) were identified as D. reticulatus and 23.0% (758/3,292) as D. marginatus, while 0.6% (19/3,292) were too damaged for species-level identification. Dermacentor reticulatus was received from all federal states of Germany. Maxent species distribution models predicted suitable environmental conditions for D. reticulatus throughout Germany. Findings on the vegetation or on pastured animals without travel history confirmed the occurrence of this tick species as far north as the most northern German federal state Schleswig-Holstein. In contrast, the distribution of D. marginatus still appears to be limited to southwestern Germany, although the northward shift of the distribution limit observed in the preceding citizen science study, as compared with previous published distributions, was confirmed. This shift was also predicted by Maxent species distribution models, reflecting the broader distribution of the tick occurrence data contributed by citizens. Most D. reticulatus ticks were found on dogs (1,311/1,960, 66.9%), while D. marginatus was mainly discovered on hoofed animals (197/621, 31.7%) and humans (182/621, 29.3%). Human tick bites were reported in 0.7% (14/1,960) of host-assigned D. reticulatus and 3.4% (21/621) of host-assigned D. marginatus. Further studies to investigate an increasing endemisation of Babesia canis in Germany as well as the relevance of D. reticulatus for TBEV spread throughout the country, e.g., by traveling dogs, are urgently needed. In view of the activity of D. reticulatus during winter or the colder months, which complements that of Ixodes ricinus, a year-round tick protection of at least dogs is strongly recommended

Systematic Analysis of Carotenogenesis in Microalgae for Model-Based Process Design

Otto-von-Guericke-Universität Magdeburg, Fakultät für Verfahrens- und Systemtechnik, Dissertation, 2017von Dipl.-Ing. Melanie FachetLiteraturverzeichnis: Seite [145]-15