Wissen auf losen Blättern im Kontext starrer Theorien

At the end of the nineteenth century, after twelve years of intensive research, the ophthalmologist Theodor Leber (1840–1917) established the chemotaxis of leukocytes as part of inflammation research. Although at the time his theory was smoothly enlisted into immunological research, up until now his name has been connected to chemotaxis only in the English-language literature. Leber was able to use his experimental system to develop a theory of the chemical attraction of the leukocytes during inflammation processes by the beginning of the 1880s, but his unconventional methodology—introducing chemically neutral contaminants in order to trigger inflammation in the eyes of rabbits—contradicted the basic bacteriological Denkstil (style of thought) of inflammation research at the time. Leber held fast to his research practice, which consisted of closely interlocking experimental and theoretical work. Only when an opening appeared in the bacteriological Denkstil was Leber able to transform his experimental observations, written on loose sheets of paper, into convincing evidence for his theory of inflammation. This micro-historical reconstruction of Leber’s experimental and written work, based on his original lab protocols, opens up the research practice of a scientist who was not recognized by the established microbiological inflammation research of the time. Moreover, persistent factors in the generation of knowledge are revealed by connecting this micro-historical reconstruction with a macro-history analysis. Indeed Leber developed his specific paper technology in order to mobilise and stabilise the scientific findings gained through experiment because of the persistence of the bacteriological Denkstil.     

Betulinic Acid in Complex with a Gamma-Cyclodextrin Derivative Decreases Proliferation and in Vivo Tumor Development of Non-Metastatic and Metastatic B164A5 Cells

Betulinic acid, a very promising anti-melanoma agent, has very low water solubility that causes low bioavailability. To overcome this inconvenience, a highly water-soluble cyclodextrin was used (octakis-[6-deoxy-6-(2-sulfanyl ethanesulfonic acid)]-γ-cyclodextrin). The complex was physico-chemically analyzed using differential scanning calorimetry (DSC), X-ray and scanning electron microscopy (SEM) methods and then in vitro tested for its antiproliferative activity by the MTT assay and by cell cycle analysis. Finally, the complex was tested in vivo using an animal model of murine melanoma developed in C57BL/6J mice, where it caused a reduction in tumor volume and weight. The study revealed the beneficial influence of betulinic acid inclusion into the cyclodextrin in terms of antiproliferative activity and in vivo tumor development.     

Interactions and Chemical Transformations of Coronene Inside and Outside Carbon Nanotubes

By exposing flat and curved carbon surfaces to coronene, a variety of van der Waals hybrid heterostructures are prepared, including coronene encapsulated in carbon nanotubes, and coronene and dicoronylene adsorbed on nanotubes or graphite via π–π interactions. The structure of the final product is determined by the temperature of the experiment and the curvature of the carbon surface. While at temperatures below and close to the sublimation point of coronene, nanotubes with suitable diameters are filled with single coronene molecules, at higher temperatures additional dimerization and oligomerization of coronene occurs on the surface of carbon nanotubes. The fact that dicoronylene and possible higher oligomers are formed at lower temperatures than expected for vapor‐phase polymerization indicates the active role of the carbon surface used primarily as template. Removal of adsorbed species from the nanotube surface is of utmost importance for reliable characterization of encapsulated molecules: it is demonstrated that the green fluorescence attributed previously to encapsulated coronene is instead caused by dicoronylene adsorbed on the surface which can be solubilized and removed using surfactants. After removing most of the adsorbed layer, a combination of Raman spectroscopy and transmission electron microscopy was employed to follow the transformation dynamics of coronene molecules inside nanotubes.     

Structural and electrochemical characterization of tin-containing graphite compounds used as anodes for Li-ion batteries

Two tin–graphite composites (“core-shell” structures) with different metal content (80 wt% and 20 wt%) as well as their structural and electrochemical characteristics are presented. Mitsubishi's synthetic carbon was used as starting material for the modification experiments. Chemical reduction was applied for the coating process, which was carried out under inert argon atmosphere. Although a homogeneous film of the nanoscale tin particles (∼60 nm) have been achieved, the electrochemical performance improvement strongly depends on the thickness of the “shell’ layer and the progressively increased active surface area together with the tin metal contents. The electrode with low metal concentration displayed both improved cycling performance and stable discharge capacity of 435 Ah kg⁻¹ compared with untreated graphite electrode. The tin-rich composite shows a higher medial discharge capacity (540 mAh g⁻¹) but increased capacity fading, while higher metal contents lead to bulk-coated film with disassociated and agglomerated tin nanoparticles as well as higher surface area and likely presence of oxide impurities.     

Variability of the plasma proteome in healthy people (report 1)

The last decade has seen intense development of proteomic technologies have opened new perspectives for rapid large-scale screening of biological samples in order to find biomarkers of various diseases or conditions. However, in order to adequately evaluate the possibility of using protein as a biomarker, it is necessary to know how much its concentration varies widely in healthy people. This project aims to explore the limits of the concentration of protein components of plasma in healthy people.     

Sorption of Pu and Np on chitin-containing materials from strongly alkaline solutions

Sorption of Pu and Np on chitin, chitosan, and chitin-containing materials from strongly alkaline (1–4 M NaOH) solutions was studied under the static and dynamic conditions in the presence of large amounts of NaNO₃. The Pu(IV) distribution coefficient (K _d) between the solutions with the NaOH concentration ranging from 1 to 4 M and different chitin-containing sorbents varies from 3000 to 6000 cm³ g^?1. The K _d of Np(V) with different sorbents decreases from 2000–4000 to 600–1200 cm³ g^?1 with increasing NaOH concentration.     

Polar Elastomers as Novel Materials for Electromechanical Actuator Applications

Dielectric elastomer actuators are stretchable capacitors capable of a musclelike actuation when charged. They will one day be used to replace malfunctioning muscles supposing the driving voltage can be reduced below 24 V. This focus here is on polar dielectric elastomers and their behavior under an electric field. Emphasis is placed on all the features that are correlated with the molecular structure, its synthetic realization, and its impact on properties. Regarding the polymer class, the focus, to some degree, is on polysiloxanes because of their attractively low glass transition temperatures. This enables introduction of highly polar groups to the backbone while maintaining soft elastic properties. The goal is to provide a few guidelines for future research in this emerging field that may be useful for those considering entering this fascinating endeavor. Because of the large number of materials available, a few restrictions in the selection have to be applied.