Acute Effects of Butyrate on Induced Hyperpermeability and Tight Junction Protein Expression in Human Colonic Tissues

Intact intestinal barrier function is essential for maintaining intestinal homeostasis. A dysfunctional intestinal barrier can lead to local and systemic inflammation through translocation of luminal antigens and has been associated with a range of health disorders. Butyrate, a short-chain fatty acid derived from microbial fermentation of dietary fibers in the colon, has been described as an intestinal barrier-strengthening agent, although mainly by using in vitro and animal models. This study aimed to investigate butyrate’s ability to prevent intestinal hyperpermeability, induced by the mast cell degranulator Compound 48/80 (C48/80), in human colonic tissues. Colonic biopsies were collected from 16 healthy subjects and intestinal permeability was assessed by Ussing chamber experiments. Furthermore, the expression levels of tight junction-related proteins were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Pre-treatment with 5 mM butyrate or 25 mM butyrate did not protect the colonic tissue against induced paracellular or transcellular hyperpermeability, measured by FITC-dextran and horseradish peroxidase passage, respectively. Biopsies treated with 25 mM butyrate prior to stimulation with C48/80 showed a reduced expression of claudin 1. In conclusion, this translational ex vivo study did not demonstrate an acute protective effect of butyrate against a chemical insult to the intestinal barrier in healthy humans

Republik Korea

SIGLEBibliothek Weltwirtschaft Kiel C 137804 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A model of the stand-by electric battery based on the system Li/KCl-LiCl-RbCl-LiF/FeS2

Opracowano model nowej baterii rezerwowej aktywowanej termicznie opartej na układzie elektrochemicznym Li|KCl-LiCl-RbCl-LiF|FeS2 oraz mieszanine grzewczej Fe-KClO4. W badaniach stosowano dwuogniwową baterią termiczną, dla której wyznaczono wartość jej pojemności cieplnej oraz określono optymalną masę tabletki mieszaniny grzewczej. Ponadto określono wpływ niedogrzania lub przegrzania baterii na podstawowe parametry elektryczne oraz wyznaczono wartości temperatury poszczególnych jej elementów.The model of a new thermally activated stand-by battery based on the electrochemical chain Li/KCl-LiCl-RbCl-LiF/FeS2 and heating composition of Fe-KClO4 was developed. A thermal two-cell battery was used for tests and its thermal capacity and the optimal mass of the heating tablet was determined. Moreover the dependence of battery electric performance on overheating and not sufficient heating was presented in the paper. There are also included temperatures of battery’s particular components

AND TABAT Theory and Experimental Results of a New Diamond Surface-Emission Cathode nikolay n. efremow, jr. is an assistant staff member in the Submicrometer Technology group, where he fabricates and characterizes diamond emitters for flat-panel displays.

■ A new electron-emission mechanism combines the enhanced electric field of a triple junction at the intersection of metal and diamond interfaces in vacuum with the negative electron affinity (NEA) of the diamond surface. This new surface-emission mechanism is compared to two common cathode mechanisms—geometric electric-field enhancement and Schottky-diode electricfield enhancement with an NEA semiconductor. Unlike these two mechanisms, in which electrons tunnel from metal into vacuum or into the conduction band of an NEA semiconductor, in our mechanism electrons tunnel from metal into surface states at the interface of an NEA semiconductor and a vacuum. Once in these states, the electrons are accelerated to sufficient energies to be emitted from the surface into vacuum. New cathodes designed to maximize the surface-emission mechanism exhibit improved consistency and reduced operating voltage when compared to cathodes that use other mechanisms. Gated surface-emission cathodes emit measurable current densities greater than 10 –6 A m –2 at gate voltages of 3 to 4 V