Muramyl dipeptide causes mitochondrial dysfunction and intestinal inflammatory cytokine responses in rats.

INTRODUCTION: Intestinal flora and the translocation of its products, such as muramyl dipeptide (MDP), are common causes of sepsis. MDP is a common activator of the intracellular pattern recognition receptor NOD2, and MDP translocation can cause inflammatory damage to the small intestine and systemic inflammatory responses in rats. Therefore, this study investigated the effects of MDP on the intestinal mucosa and distant organs during sepsis and the role of the NOD2/AMPK/LC3 pathway in MDP-induced mitochondrial dysfunction in the intestinal epithelium. METHODS: Fifty male Sprague Dawley rats were randomly divided into five treatment groups: lipopolysaccharide (LPS) only, 1.5 and 15 mg/kg MDP + LPS, and 1.5 and 15 mg/kg MDP + short-peptide enteral nutrition (SPEN) + LPS. The total caloric intake was the same per group. The rats were euthanized 24 hours after establishing the model, and peripheral blood and small intestinal mucosal and lung tissues were collected. RESULTS: Compared to the LPS group, both MDP + LPS groups had aggravated inflammatory damage to the intestinal mucosal and lung tissues, increased IL-6 and MDP production, increased NOD2 expression, decreased AMPK and LC3 expression, increased mitochondrial reactive oxygen species production, and decreased mitochondrial membrane potential. Compared to the MDP + LPS groups, the MDP + SPEN+LPS groups had decreased IL-6 and MDP production, increased AMPK and LC3 protein expression, and protected mitochondrial and organ functions. CONCLUSIONS: MDP translocation reduced mitochondrial autophagy by regulating the NOD2/AMPK/LC3 pathway, causing mitochondrial dysfunction. SPEN protected against MDP-induced impairment of intestinal epithelial mitochondrial function during sepsis.

Delayed fluorescence in a solution-processable pure red molecular organic emitter based on dithienylbenzothiadiazole: a joint optical, electroluminescence, and magnetoelectroluminescence study.

The discovery of triplet excitons participating in the photoluminescent processes in a growing number of pure organic emitters represents an exciting impetus for a diversity of promising opto, bio, and optoelectronic applications. In this contribution, we have studied a small-molecule dithienylbenzothiadiazole-based red-emitting dye red-1b, which shows clearly delayed fluorescence under optical and electrical excitation. The OLED device that contained red-1b as a nondoped solution-processable emitter exhibited a moderately high utilization of exciton amounting to ≈31% and slow efficiency roll-off. Magnetoelectroluminescence measurements revealed the coexistence of reverse intersystem crossing from the lowest triplet state to singlet state (RISC, E-type triplet to singlet up-conversion) and triplet-triplet annihilation (TTA, P-type triplet to singlet up-conversion). Specifically, in low current-density regime, the moderately high exciton utilization is attributed to RISC (i.e., thermally activated delayed fluorescence, TADF), whereas in high current-density regime, TTA may contribute to suppressing efficiency roll-off. Furthermore, the results showed that red-1b may represent a new kind of organic red emitters that display delayed fluorescence in a way differing from the few red emitters investigated so far.

Small-molecule light-emitting electrochemical cells: evidence for in situ electrochemical doping and functional operation.

We demonstrate that non-ionic small molecules (SMs) can function as the doping and emissive compound in light-emitting electrochemical cells (LECs), and that high brightness and decent efficiency can be attained for such devices. It is plausible that the expansion of the LEC library, to include easy-to-purify and tunable non-ionic SM compounds, could represent a viable path towards improved LEC devices.

Alcohol-processable organic amorphous electrolytes as an effective electron-injection layer for organic light-emitting diodes.

A new series of monoammonium-based organic electrolytes with the tetrafluoroborate (BF(4)(-)) counteranion have been synthesized. Replacing the pendant ethyl groups in the fluorenyl unit with 4-ethoxyphenyl groups dramatically improves both solubility and morphological stability. The characterization of the alcohol-processable amorphous ionic compounds as an electron-injection layer in organic light-emitting diodes (OLEDs) reveals that the organic electrolyte that comprises a rigid linear-conjugated unit provides better device performance, with respect to its counterpart containing a branched bulky moiety. The capability of these compounds to facilitate electron injection from air-stable aluminum metal is preliminarily discussed on the basis of the investigations of the electron-only devices and photovoltaic experiments.