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Trachtenberg A.J.,Massachusetts | Susa M.,Tohoku UniversitySendai | Bahammam L.,King Abdulaziz University
Anatomical Record | Year: 2016

Apical periodontitis (periapical lesions) is an infection-induced chronic inflammation in the jaw, ultimately resulting in the destruction of apical periodontal tissue. Toll-like receptors (TLRs) are prominent in the initial recognition of pathogens. Our previous study showed that TLR4 signaling is proinflammatory in periapical lesions induced by a polymicrobial endodontic infection. In contrast, the functional role of TLR2 in regulation of periapical tissue destruction is still not fully understood. Using TLR2 deficient (KO), TLR2/TLR4 double deficient (dKO), and wild-type (WT) mice, we demonstrate that TLR2 KO mice are highly responsive to polymicrobial infection-induced periapical lesion caused by over activation of TLR4 signal transduction pathway that resulted in elevation of NF-kB (nuclear factor kappa B) and proinflammatory cytokine production. The altered TLR4 signaling is caused by TLR2 deficiency-dependent elevation of CD14 (cluster of differentiation 14), which is a co-receptor of TLR4. Indeed, neutralization of CD14 strikingly suppresses TLR2 deficiency-dependent inflammation and tissue destruction in vitro and in vivo. Our findings suggest that a network of TLR2, TLR4, and CD14 is a key factor in regulation of polymicrobial dentoalveolar infection and subsequent tissue destruction. © 2016 Wiley Periodicals, Inc. Source

Williams M.C.,Tohoku UniversitySendai | Winkler W.,Tohoku UniversitySendai | Winkler W.,University of Hamburg | Suzuki A.,Tohoku UniversitySendai | Miyamoto A.,Tohoku UniversitySendai
EFC 2011 - Proceedings of the 4th European Fuel Cell Piero Lunghi Conference and Exhibition | Year: 2011

There are five useful concepts in understanding fuel cell performance. Thermal and exergetic efficiencies, power, area specific resistance (ASR), and degradation. The later two must be developed for different fuel cell operating modes. The concepts of exergetic efficiency and entropy production are related to ASR and degradation. It is shown that exergetic efficiency is a time-dependent function useful in describing the thermal efficiency of a fuel cell and the change in thermal efficiency of a degrading fuel cell. Source

Guo Y.,Tohoku UniversitySendai | Miyamoto K.-I.,Tohoku UniversitySendai | Wagner T.,FH Aachen | Schoning M.J.,FH Aachen | And 2 more authors.
Physica Status Solidi (A) Applications and Materials Science | Year: 2014

The light-addressable potentiometric sensor (LAPS) is a semiconductor-based potentiometric sensor using a light probe with an ability of detecting the concentration of biochemical species in a spatially resolved manner. As an important biomedical sensor, research has been conducted to improve its performance, for instance, to realize high-speed measurement. In this work, the idea of facilitating the device-level simulation, instead of using an equivalent-circuit model, is presented for detailed analysis and optimization of the performance of the LAPS. Both carrier distribution and photocurrent response have been simulated to provide new insight into both amplitude-mode and phase-mode operations of the LAPS. Various device parameters can be examined to effectively design and optimize the LAPS structures and setups for enhanced performance. Distribution of minority carriers inside a Si-based LAPS structure under illumination with different wavelengths. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Kadota I.,Okayama University | Sato Y.,Tohoku UniversitySendai | Fujita N.,Okayama University | Takamura H.,Okayama University | Yamamoto Y.,Tohoku UniversitySendai
Tetrahedron | Year: 2015

Abstract Convergent synthesis of the EFGH ring segment of ciguatoxin CTX3C was investigated by using the intramolecular allylation of an α-chloroacetoxy ether and/or O,S-acetal, and subsequent ring-closing metathesis. A new method for the preparation of γ-alkoxyallylstannane is also described. © 2015 Elsevier Ltd. Source

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