分类： 生物学 >> 生物物理学 提交时间： 2016-05-11
Zhang, Jingjing
Yang, Zhenguo
Chen, Huapu
Wang, Sijie
Fan, Yiming
Zhang, Jingjing
Piontek, Anna
Qin, Zhihai
Piontek, Joerg
Ni, Chen
摘要： Claudins (Cldn) are the major components of tight junctions (TJs) sealing the paracellular cleft in tissue barriers of various organs. Zebrafish Cldnb, the homolog of mammalian Cldn4, is expressed at epithelial cell-cell contacts and is important for regulating epidermal permeability. The bacterial toxin Clostridium perfringens enterotoxin (CPE) has been shown to bind to a subset of mammalian Cldns. In this study, we used the Cldn-binding C-terminal domain of CPE (194-319 amino acids, cCPE(194-319)) to investigate its functional role in modulating zebrafish larval epidermal barriers. In vitro analyses show that cCPE(194-319) removed Cldn4 from epithelial cells and disrupted the monolayer tightness, which could be rescued by the removal of cCPE(194-319). Incubation of zebrafish larvae with cCPE(194-319) removed Cldnb specifically from the epidermal cell membrane. Dye diffusion analysis with 4-kDa fluorescent dextran indicated that the permeability of the epidermal barrier increased due to cCPE(194-319) incubation. Electron microscopic investigation revealed reversible loss of TJ integrity by Cldnb removal. Collectively, these results suggest that cCPE(194-319) could be used as a Cldnb modulator to transiently open the epidermal barrier in zebrafish. In addition, zebrafish might be used as an invivo system to investigate the capability of cCPE to enhance drug delivery across tissue barriers.
分类： 电子与通信技术 >> 电子技术 分类： 工程与技术科学 >> 仪器仪表技术 分类： 物理学 >> 交叉学科物理及相关领域的科学与技术 分类： 物理学 >> 凝聚态:电子结构、电、磁和光学性质 提交时间： 2024-05-06
摘要： In this work, we design and fabricate the transimpedance Amplifier (TIA) following the design mentioned in Ref. cite{Liang2024}. In the TIA, the preamplifier (Pre-Amp) is made of a junction field effect transistor (JFET) that can work at 77 K. The post-amplifier is made of an operational amplifier (OPA). Cascade Pre-Amp and Post-Amp to form the inverting-amplifier (Inv-Amp). The gain-bandwidth product of Inv-Amp with the gain about 50,000 is higher than 10 GHz. With a 1.13 Gohm feedback network, the gain of TIA is 1.13 Gohm and its bandwidth is about 97 kHz. The equivalent input noise voltage power spectral density of TIA is not more than 9 (nV)2/Hz at 10 kHz and 4 (nV)2/Hz at 50kHz, and its equivalent input noise current power spectral density is about 26 (fA)2/Hz at 10 kHz and 240(fA)2/Hz at 50 kHz. The measured transport performances and noise performances of TIA are consistent with the simulations and calculations, verifying the feasibility for the design of low-noise large-bandwidth TIA proposed in Ref. 1 . And, TIA with various performances that meet various needs can be designed according to the design methods in Ref. 1,2 . With the same gain, the bandwidth of the TIA in this work is much larger than the present TIA and its noises are much lower than those of present ones. The TIA in this work is perfect for the cryogenic STM working at 77 K (i.e. liquid nitrogen temperature).
提交时间： 2017-05-02
Qian, M [Qian, Min][ 1,2 ]
Zhang, R [Zhang, Ran][ 3,4 ]
Hao, JY [Hao, Jingyu][ 3,4 ]
Zhang, WJ [Zhang, Wenjun][ 5 ]
Zhang, Q [Zhang, Qin][ 3,4 ]
Wang, JP [Wang, Jianpu][ 1,2 ]
Tao, YT [Tao, Youtian][ 1,2 ]
Chen, SF [Chen, Shufen][ 3,4 ]
Fang, JF [Fang, Junfeng][ 5 ]
Huang, W [Huang, Wei][ 1,2,3,4 ]
摘要： Various low ratios of triplet iridium complexes [0, 0.5, 1, 1.5, 2.5, and 5 mol%] are conjugated to the backbone of the famous champion donor polymer PTB7. At the same conditions, the power conversion efficiency for polymer containing 1% of Ir increases b
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