Bragg-Gitter für das Lichtmanagement in organischen Leuchtdioden

Diese Arbeit befasst sich mit dem Einsatz von Bragg-Gittern für das Lichtmanagement in organischen Leuchtdioden. Das Hauptaugenmerk liegt dabei auf der Auskopplung von geführten Wellenleitermoden in den organischen Schichten und der Anode der OLEDs. Die untersuchten Gitterstrukturen erlauben es zudem, die Abstrahlung über Microcavity-Effekte zu beeinflussen und Substratmoden gezielt auszukoppeln

Virtuelle Competence Center – Verteilte Kompetenzen vernetzen und nutzbar machen.

Aus der Zusammenfassung: "Produkt- und Prozessinnovationen sind im heutigen Wettbewerbsumfeld zunehmend schnelllebiger. Damit steigt der Aufwand für die Erhaltung und den Ausbau des vorhanden Kompetenz- bzw. Wissensvorsprungs. Insbesondere die kosteneffiziente Nutzung und Erschließung unternehmensweit oder firmenübergreifend verteilter Kompetenzen und Wissensressourcen wird entscheidend für den Markterfolg.

Squalane is in the midplane of the lipid bilayer: implications for its function as a proton permeability barrier

AbstractA recently proposed model for proton leakage across biological membranes [Prog. Lipid Res. 40 (2001) 299] suggested that hydrocarbons specifically in the center of the lipid bilayer inhibit proton leaks. Since cellular membranes maintain a proton electrochemical gradient as a principal energy transducer, proton leakage unproductively consumes cellular energy. Hydrocarbons in the bilayer are widespread in membranes that sustain such gradients. The alkaliphiles are unique in that they contain up to 40 mol% isoprenes in their membranes including 10–11 mol% squalene [J. Bacteriol. 168 (1986) 334]. Squalene is a polyisoprene hydrocarbon without polar groups. Localizing hydrocarbons in lipid bilayers has not been trivial. A myriad of physical methods including fluorescence spectroscopy, electron-spin resonance, nuclear magnetic resonance as well as X-ray and neutron diffraction have been used to explore this question with various degrees of success and often contradictory results. Seeking unambiguous evidence for the localization of squalene in membranes or lipid bilayers, we employed neutron diffraction. We incorporated 10 mol% perdeuterated or protonated squalane, an isosteric analogue of squalene, into stacked bilayers of dioleoyl phosphatidyl choline (DOPC) doped with dioleoyl phosphatidyl glycerol (DOPG) to simulate the negative charges found on natural membranes. The neutron diffraction data clearly show that the squalane lies predominantly in the bilayer center, parallel to the plane of the membrane

Neutron diffraction reveals sequence-specific membrane insertion of pre-fibrillar islet amyloid polypeptide and inhibition by rifampicin

AbstractHuman islet amyloid polypeptide (hIAPP) forms amyloid deposits in non-insulin-dependent diabetes mellitus (NIDDM). Pre-fibrillar hIAPP oligomers (in contrast to monomeric IAPP or mature fibrils) increase membrane permeability, suggesting an important role in the disease. In the first structural study of membrane-associated hIAPP, lamellar neutron diffraction shows that oligomeric hIAPP inserts into phospholipid bilayers, and extends across the membrane. Rifampicin, which inhibits hIAPP-induced membrane permeabilisation in functional studies, prevents membrane insertion. In contrast, rat IAPP (84% identical to hIAPP, but non-amyloidogenic) does not insert into bilayers. Our findings are consistent with the hypothesis that membrane-active pre-fibrillar hIAPP oligomers insert into beta cell membranes in NIDDM

Development of a process chain for multi-stage sheet metal forming of high-strength aluminium alloys

The high-strength aluminium alloys EN AW-6082 and -7075 are characterized by low density and high strength but also limited cold formability and pronounced springback behaviour in the ultra-high-strength T6 state. In order to exploit their lightweight design potential, temperature-supported process routes such as warm or hot forming are applied. Alternatively, there is the possibility of cold forming preconditioned semi-finished products at the expense of the initial material properties. Common to all variants are complex interrelationships due to linked plant periphery resulting from up- and downstream heat treatments. In addition, occurring heat transfers in temperature-supported process routes or strain hardening effects during cold forming lead to reduced formability. Especially for multi-stage forming processes, as they are required for complex components, the above-mentioned process routes reach their limits. The different requirements of the four single-stages (deep drawing, blanking, collar drawing and upsetting) for the production of a demonstrator geometry with adapted wall thicknesses make a new type of temperature control necessary. This paper shows that the combination of temperature-supported and multi-stage forming contributes to a significant increase in formability. The temperature-controlled forming tool used for this purpose enables an inline heating of the components during the process, so that an industrially feasible and economical overall process chain for the fabrication of the demonstrator geometry out of those alloys is convertible

Cost‐effectiveness of multi‐layered silicone foam dressings for prevention of sacral and heel pressure ulcers in high‐risk intensive care unit patients: An economic analysis of a randomised controlled trial

Pressure ulcer incidence is high in intensive care units. This causes a serious financial burden to healthcare systems. We evaluated the cost-effectiveness of multi-layered silicone foam dressings for prevention of sacral and heel pressure ulcers in addition to standard prevention in high-risk intensive care units patients. A randomised controlled trial to assess the efficacy of multi-layered silicone foam dressings to prevent the development of pressure ulcers on heels and sacrum among 422 intensive care unit patients was conducted. Direct costs for preventive dressings in the intervention group and costs for treatment of incident pressure ulcers in both groups were measured using a bottom-up approach. A cost-effectiveness analysis by calculating the incremental cost-effectiveness ratio using different assumptions was performed. Additional dressing and labour costs of €150.81 (€116.45 heels; €34.36 sacrum) per patient occurred in the intervention group. Treatment costs were €569.49 in the control group and €134.88 in the intervention group. The incremental cost-effectiveness ratio was €1945.30 per PU avoided (€8144.72 on heels; €701.54 sacrum) in the intervention group. We conclude that application of preventive dressings is cost-effective for the sacral area, but only marginal on heels for critically ill patients