Redoxchemische Varianten der Synthese von neuartigen Imino-Nitroxiden, Nitronyl-Nitroxiden und Nitronyl-Nitrosonium-Systemen.

1. C(2) functionalisation of nitronyl nitroxides with electrophiles 2. C(2) functionalisation of nitronyl nitroxides with nucleophiles 3. Nucleophilic substitution at the C(2) centre of the C(2)-Br nitronyl nitroxide 4. Reaction of the C(2)-I nitronyl nitrosonium system with nuceophiles 5. Reaction of the C(2)-Br nitronyl nitrosonium system with nucleophiles 6. Reactions of the C(2)-H nitronyl nitrosonium salt with nucleophiles a. Reactions of the C(2)-H nitronyl nitrosonium systems with protogenic nucleophiles 7. Reaction of the nitronyl nitrosonium systems C(2)-H, C(2)-Br and C(2)-I with electron rich nucleophiles. 8. Substitution of the onio substituent in the nitronyl nitroxide system 9. Synthesis of paramagnetic carbenes of the Arduengo/Wanzlick type 10. Synthesis of the metal complexes of nitronyl nitroxides 11. Synthesis of the metal complexes of imino nitroxides 12. General concept for the synthesis of electronic analogous of nitronyl nitroxides 13. Reaction of the C(2)-phynyl imino nitroxide with elektrophiles 14. Reaction of the C(2)-phynyl nitronyl nitroxide with iso pentyl nitrite 15. Reaction of the C(2)-(H) nitronyl nitroxide with iso pentyl nitrite1. C(2)-Funktionalisierung der Nitronyl-Nitroxide mit Elektrophilen 2. C(2)-Funktionalisierung der Nitronyl-Nitroxide mit Nukleophilen 3. Nukleophile Substitutionen am C(2)-Atom des C(2)-Br-Nitronyl-Nitroxids 4. Umsetzungen des C(2)-I-Nitronyl-Nitrosonium-Systems mit Nukleophilen 5. Umsetzung des C(2)-Br-Nitronyl-Nitrosonium-Systems mit Nukleophilen 6. Umsetzungen des C(2)-H-Nitronyl-Nitrosonium-Salzes mit Nukleophilen. a. Umsetzungen des C(2)-H-Nitronyl-Nitrosonium-Systems mit protogenen Nukleophilen. 7. Umsetzungen der Nitronyl-Nitrosonium-Systeme C(2)-H-, C(2)-Br- und C(2)- I- mit elektronenreichen Nukleophilen. 8. Austausch des Onio-Substituenten im System der Nitronyl-Nitroxide 9. Synthese paramagnetischer Carbene des Arduengo-Wanzlick Typs 10. Synthese von Metallkomplexen der Nitronyl-Nitroxide 11. Synthese von Metallkomplexen der Imino-Nitroxide 12. Allgemeines Konzept der Synthese von elektronischen Analoga der Nitronyl-Nitroxide 13. Umsetzung des C(2)-Phenyl-Imino-Nitroxids mit Elektrophilen 14. Umsetzung des C(2)-Phenyl-Nitronyl-Nitroxids mit Isopentylnitrit 15. Umsetzung des C(2)-H-Nitronyl-Nitroxids mit Isopentylnitri

Konzentrationsänderungen von Kalium in Gläsern während der Elektronenstrahlmikroanalyse

Die Intensitätsabnahme der charakteristischen Röntgenstrahlung mit der Zeit bei der Elektronenstrahlmikroanalyse wurde in Abhängigkeit von der Schichtdicke des aufgedampften leitenden Materials, vom Elektronenstrahldurchmesser, von der Elektronenstrahlleistung und von der Art des aufgedampften Materials untersucht. Aus den experimentellen Ergebnissen wurden Arbeitsbedingungen abgeleitet, die es gestatten, auch quantitative Mikroanalysen an Silicatgläsern durchzuführen. Die Vorgänge bei der Konzentrationsänderung der Alkalimetalle im angeregten Probenvolumen werden an Hand eines Modells gedeutet, das auch den Anstieg der Alkalimetallintensitäten mit einbezieht

Hochwärmeleitfähige Polymer-Compounds

Nach dem aktuellen Stand der Technik werden wärmeleitfähige thermoplastische Compounds vermehrt für Bauteile mit Entwärmungsaufgaben eingesetzt und haben somit metallische Bauteile zum Teil verdrängt. Einsatzbereiche finden sich in der Elektronik, Mechatronik aber auch in technischen Teilen in der Automobilindustrie, da bspw. die Verarbeitbarkeit im Spritzgießverfahren mehr Freiheiten bei der Formgebung ermöglicht. Weiterhin besitzen wärmeleitfähige Kunststoff-Compounds gegenüber metallischen Materialien eine wesentlich geringere Dichte und sie erlauben eine gezielte Einstellung der Materialeigenschaften durch die Variation der Füllstoffe und des Füllstoffanteils. Als Füllstoffe für wärmeleitfähige Kunststoffe haben sich organi-sche Füllstoffe (z.B. Graphit), metallische Füllstoffe (z.B. Kupfer) und keramische Füllstoffe (z.B. Bornitrid) durchgesetzt. Die Wärmeleitfähigkeitswerte von kommerziell erhältlichen Compounds liegen laut den Herstellerangaben zwischen 1 W/mK und 20 W/mK und somit um den Faktor 10 bis 100 über dem von ungefüllten Polymeren. Diese Werte konnten jedoch im Rahmen der hier vorgestellten Untersuchungen auf bis zu 30 W/mK gesteigert werden. Zum Erreichen solch hoher thermischen Leitfähigkeiten wurden bis zu 80 Gew.% an Füllstoffen in verschiedene Polymere eingebracht. Mittels einer Vielzahl an Versuchsreihen wurden neben der Wärmeleitfähigkeit auch der Einfluss auf die mechanischen Kennwerte sowie die Verarbeitbarkeit der Materialien im Extrusions- und Spritzgießprozess betrachtet. Durch den Spritzgießprozess kommt es bei gefüllten Compounds zur einer strömungsinduzierten Orientierung der Füllstoffpartikel im Bauteil. Mittels Raster-Elektronen- Mikroskop-Aufnahmen von verschiedenen Probekörpern konnte eine anisotrope Schichtstruktur nachgewiesen werden, die die Wärmeleitfähigkeit signifikant beeinflusst und eine Differenzierung der Wärmeleitfähigkeit in „through-plane“ und „in-plane“-Richtung erfordert

Explain yourself! Effects of Explanations in Human-Robot Interaction

Recent developments in explainable artificial intelligence promise the potential to transform human-robot interaction: Explanations of robot decisions could affect user perceptions, justify their reliability, and increase trust. However, the effects on human perceptions of robots that explain their decisions have not been studied thoroughly. To analyze the effect of explainable robots, we conduct a study in which two simulated robots play a competitive board game. While one robot explains its moves, the other robot only announces them. Providing explanations for its actions was not sufficient to change the perceived competence, intelligence, likeability or safety ratings of the robot. However, the results show that the robot that explains its moves is perceived as more lively and human-like. This study demonstrates the need for and potential of explainable human-robot interaction and the wider assessment of its effects as a novel research direction

The ␥-Aminobutyrate Permease GabP Serves as the Third Proline Transporter of Bacillus subtilis

b PutP and OpuE serve as proline transporters when this imino acid is used by Bacillus subtilis as a nutrient or as an osmostress protectant, respectively. The simultaneous inactivation of the PutP and OpuE systems still allows the utilization of proline as a nutrient. This growth phenotype pointed to the presence of a third proline transport system in B. subtilis. We took advantage of the sensitivity of a putP opuE double mutant to the toxic proline analog 3,4-dehydro-DL-proline (DHP) to identify this additional proline uptake system. DHP-resistant mutants were selected and found to be defective in the use of proline as a nutrient. Whole-genome resequencing of one of these strains provided the lead that the inactivation of the ␥-aminobutyrate (GABA) transporter GabP was responsible for these phenotypes. DNA sequencing of the gabP gene in 14 additionally analyzed DHPresistant strains confirmed this finding. Consistently, each of the DHP-resistant mutants was defective not only in the use of proline as a nutrient but also in the use of GABA as a nitrogen source. The same phenotype resulted from the targeted deletion of the gabP gene in a putP opuE mutant strain. Hence, the GabP carrier not only serves as an uptake system for GABA but also functions as the third proline transporter of B. subtilis. Uptake studies with radiolabeled GABA and proline confirmed this conclusion and provided information on the kinetic parameters of the GabP carrier for both of these substrates

Unc5B Interacts with FLRT3 and Rnd1 to Modulate Cell Adhesion in Xenopus Embryos

The FLRT family of transmembrane proteins has been implicated in the regulation of FGF signalling, neurite outgrowth, homotypic cell sorting and cadherin-mediated adhesion. In an expression screen we identified the Netrin receptors Unc5B and Unc5D as high-affinity FLRT3 interactors. Upon overexpression, Unc5B phenocopies FLRT3 and both proteins synergize in inducing cell deadhesion in Xenopus embryos. Morpholino knock-downs of Unc5B and FLRT3 synergistically affect Xenopus development and induce morphogenetic defects. The small GTPase Rnd1, which transmits FLRT3 deadhesion activity, physically and functionally interacts with Unc5B, and mediates its effect on cell adhesion. The results suggest that FLRT3, Unc5B and Rnd1 proteins interact to modulate cell adhesion in early Xenopus development

Effects of obstructive sleep apnea and its treatment over the erectile function: a systematic review

Erectile dysfunction (ED) is considered a condition with a broad range of etiologies. Obstructive sleep apnea (OSA) syndrome is one of the lesser studied risk factors for ED. We intend to summarize the current evidence on the relationship between OSA and sexual impairment, focusing on the results in terms of erectile function of the different therapies offered to OSA patients. A systematic review was conducted, selecting articles related to the physiology of OSA and ED, and to the treatments of OSA syndrome and their reported outcomes in erectile and sexual function. Higher prevalences of ED in the OSA groups have been published. However, whether this effect on the erectile function occurs in the entire range of OSA severities remains unclear. Several hypotheses were proposed to explain the physiology of this association. Continuous Positive Airway Pressure as a treatment for OSA patients with ED has achieved a significative improvement in the sexual parameters in most of the studies. Phosphodiesterase type 5 inhibitors (iPDE5) on demand are useful as a treatment for ED in this subgroup of patients, with high satisfaction rates. The surgical treatment for the OSA evidenced benefits over the erectile function, and the effect on the sexual satisfaction of the therapy using Mandibular Advancement Devices is still undefined

Cell Discovery / Cancer cell specific inhibition of Wnt/-catenin signaling by forced intracellular acidification

Use of the diabetes type II drug Metformin is associated with a moderately lowered risk of cancer incidence in numerous tumor entities. Studying the molecular changes associated with the tumor-suppressive action of Metformin we found that the oncogene SOX4, which is upregulated in solid tumors and associated with poor prognosis, was induced by Wnt/-catenin signaling and blocked by Metformin. Wnt signaling inhibition by Metformin was surprisingly specific for cancer cells. Unraveling the underlying specificity, we identified Metformin and other Mitochondrial Complex I (MCI) inhibitors as inducers of intracellular acidification in cancer cells. We demonstrated that acidification triggers the unfolded protein response to induce the global transcriptional repressor DDIT3, known to block Wnt signaling. Moreover, our results suggest that intracellular acidification universally inhibits Wnt signaling. Based on these findings, we combined MCI inhibitors with H+ ionophores, to escalate cancer cells into intracellular hyper-acidification and ATP depletion. This treatment lowered intracellular pH both in vitro and in a mouse xenograft tumor model, depleted cellular ATP, blocked Wnt signaling, downregulated SOX4, and strongly decreased stemness and viability of cancer cells. Importantly, the inhibition of Wnt signaling occurred downstream of -catenin, encouraging applications in treatment of cancers caused by APC and -catenin mutations.(VLID)270614