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271.
Olga Malinkiewicz Thais Grancha Agustin Molina‐Ontoria Alejandra Soriano Hicham Brine Henk J. Bolink 《Liver Transplantation》2013,3(4):472-477
Simple bilayer solar cells, using commercially available cationic cyanine dyes as donors and evaporated C60 layer as an acceptor are prepared. Cyanine dyes with absorption maxima of 578, 615 and 697 nm having either perchlorate or hexafluorophosphate counter‐ions are evaluated. The perchlorate dye leads to cells with S‐shape current‐voltage curves; only the dyes with the hexafluorophosphate counter‐ions lead to efficient solar cells. When the wide bandgap dyes are employed, S‐shape current‐voltage curves are obtained when the conductive polymer PEDOT:PSS is used as hole transport layer. Substitution of PEDOT:PSS with MoO3 leads to cells with more rectangular current–voltage curves and high fill factors. Additionally, the cells using the MoO3 layer for hole extraction lead to high open circuit voltages of 0.9 V. In the case that a low bandgap hexafluorophosphate dye is used with the HOMO above that of the PEDOT:PSS the cell performance is independent on the type of hole transport layer employed. Using this approach, bilayer solar cells are obtained with power efficiencies ranging from 1.8 to 2.9% depending on the particular dye employed. These are impressive numbers for bilayer solar cell that are partially solution processed in ambient conditions. 相似文献
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Yuwon Park Nam‐Soon Choi Sangjin Park Seung Hee Woo Soojin Sim Bo Yun Jang Seung M. Oh Soojin Park Jaephil Cho Kyu Tae Lee 《Liver Transplantation》2013,3(2):206-212
Remarkable improvements in the electrochemical performance of Si materials for Li‐ion batteries have been recently achieved, but the inherent volume change of Si still induces electrode expansion and external cell deformation. Here, the void structure in Si‐encapsulating hollow carbons is optimized in order to minimize the volume expansion of Si‐based anodes and improve electrochemical performance. When compared to chemical etching, the hollow structure is achieved via electroless etching is more advanced due to the improved electrical contact between carbon and Si. Despite the very thick electrodes (30 ~ 40 μm), this results in better cycle and rate performances including little capacity fading over 50 cycles and 1100 mA h g?1 at 2C rate. Also, an in situ dilatometer technique is used to perform a comprehensive study of electrode thickness change, and Si‐encapsulating hollow carbon mitigates the volume change of electrodes by adoption of void space, resulting in a small volume increase of 18% after full lithiation corresponding with a reversible capacity of about 2000 mA h g?1. 相似文献
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Ryunosuke Ohkawa Hann Low Nigora Mukhamedova Ying Fu Shao-Jui Lai Mai Sasaoka Ayuko Hara Azusa Yamazaki Takahiro Kameda Yuna Horiuchi Peter J. Meikle Gerard Pernes Graeme Lancaster Michael Ditiatkovski Paul Nestel Boris Vaisman Denis Sviridov Andrew Murphy Alan T. Remaley Dmitri Sviridov Minoru Tozuka 《Journal of lipid research》2020,61(12):1577
Lipoproteins play a key role in transport of cholesterol to and from tissues. Recent studies have also demonstrated that red blood cells (RBCs), which carry large quantities of free cholesterol in their membrane, play an important role in reverse cholesterol transport. However, the exact role of RBCs in systemic cholesterol metabolism is poorly understood. RBCs were incubated with autologous plasma or isolated lipoproteins resulting in a significant net amount of cholesterol moved from RBCs to HDL, while cholesterol from LDL moved in the opposite direction. Furthermore, the bi-directional cholesterol transport between RBCs and plasma lipoproteins was saturable and temperature-, energy-, and time-dependent, consistent with an active process. We did not find LDLR, ABCG1, or scavenger receptor class B type 1 in RBCs but found a substantial amount of ABCA1 mRNA and protein. However, specific cholesterol efflux from RBCs to isolated apoA-I was negligible, and ABCA1 silencing with siRNA or inhibition with vanadate and Probucol did not inhibit the efflux to apoA-I, HDL, or plasma. Cholesterol efflux from and cholesterol uptake by RBCs from Abca1+/+ and Abca1−/− mice were similar, arguing against the role of ABCA1 in cholesterol flux between RBCs and lipoproteins. Bioinformatics analysis identified ABCA7, ABCG5, lipoprotein lipase, and mitochondrial translocator protein as possible candidates that may mediate the cholesterol flux. Together, these results suggest that RBCs actively participate in cholesterol transport in the blood, but the role of cholesterol transporters in RBCs remains uncertain. 相似文献
277.
Hayuki Sugimoto Yuichi Nakajima Ayaka Motoyama Erina Katagiri Takeshi Watanabe Kazushi Suzuki 《Biopolymers》2020,111(1):e23339
Chitin-binding protein 21 (CBP21) from Serratia marcescens is a lytic polysaccharide monooxygenase that contains a copper ion as a cofactor. We aimed to elucidate the unfolding mechanism of CBP21 and the effects of Cu2+ on its structural stability at pH 5.0. Thermal unfolding of both apo- and holoCBP21 was reversible. ApoCBP21 unfolded in a simple two-state transition manner. The peak temperature of the DSC curve, tp, for holoCBP21 (74.4°C) was about nine degrees higher than that for apoCBP21 (65.6°C). The value of tp in the presence of excess Cu2+ was around 75°C, indicating that Cu2+ does not dissociate from the protein molecule during unfolding. The unfolding mechanism of holoCBP21 was considered to be as follows: N∙Cu2+ ⇌ U∙Cu2+, where N and U represent the native and unfolded states, respectively. Urea-induced equilibrium unfolding analysis showed that holoCBP21 was stabilized by 35 kJ mol−1 in terms of the Gibbs energy change for unfolding (pH 5.0, 25°C), compared with apoCBP21. The increased stability of holoCBP21 was considered to result from the structural stabilization of the protein-Cu2+ complex itself. 相似文献
278.
Jianhua Ren Yuan Tian Ekram Hossain Joshua S. Ho Yadwinder S. Mann Yuntao Zhang Michael D. Browne Michael D. Connolly Ronald N. Zuckermann 《Biopolymers》2020,111(7):e23358
Peptoids belong to a class of sequence-controlled polymers comprising of N-alkylglycine. This study focuses on using tandem mass spectrometry techniques to characterize the fragmentation patterns of a set of singly and doubly protonated peptoids consisting of one basic residue placed at different positions. The singly protonated peptoids fragment by producing predominately high-abundant C-terminal ions called Y-ions and low-abundant N-terminal ions called B-ions. Computational studies suggest that the proton affinity (PA) of the C-terminal fragments is generally higher than that of the N-terminal fragments, and the PA of the former increases as the fragments are elongated. The B-ions are likely formed upon dissociating the proton-activated amide bonds via an oxazolone structure, and the Y-ions are produced subsequently by abstracting a proton from the newly formed B-ions, which is energetically favored. The doubly protonated peptoids prefer to fragment closest to either the N- or the C-terminus and produce corresponding B/Y-ion pairs. The basic residue seems to dictate the preferred fragmentation site, which may be the result of minimizing the repulsion between the two charges. Water and terminal neutral losses are a facile process accompanying the peptoid fragmentation in both charge states. The patterns appear to be highly influenced by the location of the basic residue. 相似文献
279.
Rui-Gang Zhang Chung-Yin Yip Ke-wu Pan Meng-yun Cai Wing-Hung Ko 《Journal of cellular physiology》2020,235(11):8387-8401
We investigated the regulation of Cl− secretion by adrenoceptors in polarized 16HBE14o- human bronchial epithelial cells. Treatment with the nonselective β adrenoceptor agonist isoprenaline stimulated an increase in short-circuit current (ISC), which was inhibited by the β adrenoceptor blocker propranolol. Treatment with procaterol, an agonist specific for the β2 adrenoceptor subtype, stimulated a similar increase in ISC, which was inhibited by the β2 adrenoceptor antagonist ICI 118551. Inhibitors of cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated Cl− channel (CaCC), but not K+ channel blockers, were able to inhibit the increase in ISC. “Trimultaneous” recording of ISC and intracellular cyclic adenosine monophosphate (cAMP) and Ca2+ levels in 16HBE14o- epithelia confirmed that the ISC induced by isoprenaline or procaterol involved both cAMP and Ca2+ signaling. Our results demonstrate that β2 adrenoceptors regulate Cl− secretion in the human airway epithelium by activating apical CFTRs and CaCCs via cAMP-dependent and intracellular Ca2+-dependent mechanisms, respectively. 相似文献
280.