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51.
All‐Nanomat Lithium‐Ion Batteries: A New Cell Architecture Platform for Ultrahigh Energy Density and Mechanical Flexibility 下载免费PDF全文
Ju‐Myung Kim Jeong A. Kim Seung‐Hyeok Kim In Sung Uhm Sung Joong Kang Guntae Kim Sun‐Young Lee Sun‐Hwa Yeon Sang‐Young Lee 《Liver Transplantation》2017,7(22)
The ongoing surge in demand for high‐energy/flexible rechargeable batteries relentlessly drives technological innovations in cell architecture as well as electrochemically active materials. Here, a new class of all‐nanomat lithium‐ion batteries (LIBs) based on 1D building element‐interweaved heteronanomat skeletons is demonstrated. Among various electrode materials, silicon (Si, for anode) and overlithiated layered oxide (OLO, for cathode) materials are chosen as model systems to explore feasibility of this new cell architecture and achieve unprecedented cell capacity. Nanomat electrodes, which are completely different from conventional slurry‐cast electrodes, are fabricated through concurrent electrospinning (for polymeric nanofibers) and electrospraying (for electrode materials/carbon nanotubes (CNTs)). Si (or rambutan‐shaped OLO/CNT composite) powders are compactly embedded in the spatially interweaved polymeric nanofiber/CNT heteromat skeletons that play a crucial role in constructing 3D‐bicontinuous ion/electron transport pathways and allow for removal of metallic foil current collectors. The nanomat Si anodes and nanomat OLO cathodes are assembled with nanomat Al2O3 separators, leading to the fabrication of all‐nanomat LIB full cells. Driven by the aforementioned structural/chemical uniqueness, the all‐nanomat full cell shows exceptional improvement in electrochemical performance (notably, cell‐based gravimetric energy density = 479 W h kgCell?1) and also mechanical deformability, which lie far beyond those achievable with conventional LIB technologies. 相似文献
52.
Epidermal growth factor (EGF) has been considered a potential regulator of meiotic and cytoplasmic maturation in mammalian oocytes, but inconsistencies exist between earlier studies, probably due to differences in the culture conditions used. Using a serum- and hormone-free in vitro maturation (IVM) medium, this study investigated the specific contribution of EGF on IVM of porcine (Sus scrofa) oocytes and its interactive effects with follicle-stimulating hormone (FSH), porcine follicular fluid (pFF), cumulus cells, and serum. It was noteworthy that EGF functionally mimicked the action of FSH and could completely replace FSH for nuclear maturation (83.2 ± 4.4% vs. 55.9 ± 5.2%; mean ± SEM), whereas EGF had a synergistic effect with FSH on cytoplasmic maturation of porcine oocytes (P < 0.05). Specific inhibition of EGF receptor (EGFR) by tyrphostin AG 1478 inhibited both EGF- and FSH-induced meiotic resumption (17.9 ± 5.2% and 18.2 ± 4.4%, respectively), thereby suggesting that EGFR signaling pathway was essential for oocyte reentry into the meiotic cell cycle. Furthermore, it is possible that FSH action occurs via the EGFR signaling pathway to induce meiotic maturation, although alternate pathways could not be excluded. There were also individual or combined effects of cumulus cells, FSH, serum, and pFF with EGF on IVM of porcine oocytes (P < 0.05). Although FSH had a synergistic effect with EGF on cytoplasmic maturation, pFF masked the effects of EGF on both nuclear and cytoplasmic maturation of porcine oocytes (P < 0.05). Moreover, the presence of cumulus cells was essential for EGF action. In conclusion, a defined system was used to better examine the effects of EGF. We inferred that EGF functionally mimics FSH for nuclear maturation of porcine oocytes, and its exogenous supplementation into IVM medium can optimize the beneficial effects of FSH on cytoplasmic maturation of oocytes to obtain enhanced embryo development in vitro. 相似文献
53.
Goring DR Banks P Fallis L Baszczynski CL Beversdorf WD Rothstein SJ 《The Plant journal : for cell and molecular biology》1992,2(6):999-1003
We have previously described a developmentally regulated mRNA in maize that accumulates in mature embryos and is involved in a variety of stress responses in the plant. The sequence of the encoded 16 kDa protein (MA16) predicts that it is an RNA-binding protein, since it possesses a ribonucleoprotein consensus sequence-type RNA-binding domain (CS-RBD). To assess the predicted RNA binding property of the protein and as a starting point to characterize its function we have used ribohomopolymer-binding assays. Here we show that the MA16-encoded protein binds preferentially to uridine- and guanosine-rich RNAs. In light of these results a likely role for this protein in RNA metabolism during late embryogenesis and in the stress response is discussed. 相似文献
54.
55.
Hayley M Bennett Hoi Ping Mok Effrossyni Gkrania-Klotsas Isheng J Tsai Eleanor J Stanley Nagui M Antoun Avril Coghlan Bhavana Harsha Alessandra Traini Diogo M Ribeiro Sascha Steinbiss Sebastian B Lucas Kieren SJ Allinson Stephen J Price Thomas S Santarius Andrew J Carmichael Peter L Chiodini Nancy Holroyd Andrew F Dean Matthew Berriman 《Genome biology》2014,15(11)
56.
Purified inulinase (inulase, 2,1-β-d-fructan fructanohydrolase, EC 3.2.1.7) of Kluyveromyces fragilis has been immobilized on 2-aminoethyl-cellulose by treatment with 2% glutaraldehyde in 0.05 m phosphate buffer, pH 7.0, for 2 h at room temperature. The immobilized enzyme preparation had 39.3 units inulinase activity per gram dried matrix, with 53.4% recovery yield of activity, and showed good operational stability in the presence of substrate, inulin or the tuber extract of Jerusalem artichoke. Optimum pH and temperature were 5.5 and 45°C, respectively. In a batch reactor, the conversion was 90% () and 34 mg d-fructose per ml was produced from the artichoke tuber extract by the immobilized inulinase in 20 h. In column reactor packed with 28 ml immobilized enzyme, the following conditions were found to be optimal: height/diameter ratio of column, 10.3; space time, 3.8 h; temperature, 40°C. Operation under these conditions gave 90% conversion of a 7% inulin solution and the productivity was 102 mmol l?1 h?1. 相似文献
57.
The excitatory neurotransmitter, glutamate, generates a characteristic burst-pause type of firing in midbrain dopamine neurons in association with the reward behavior, but the cellular mechanism by which glutamate generates these bursts is unknown. Here, we show that the bursts in spontaneously firing dopamine neurons can be generated by the combinative actions of the brief stimulatory and the subsequent Ca(2+)-dependent inhibitory signals in response to glutamate stimulation. The two Ca(2+)-dependent firing-extinction signals are activated by different glutamate receptors. Although the activation of metabotropic glutamate receptors rapidly stopped the enhanced firing through the Ca(2+) release from intracellular stores, the activation of NMDA and AMPA/kainate receptors abolished the firing immediately after termination of the stimulation due to the Ca(2+) accumulation in the cell. These two Ca(2+)-dependent inhibitory mechanisms appear to participate in the generation of characteristic bursts in dopamine neurons by controlling the maximum firing number of single bursts and the duration of post-firing pauses. 相似文献
58.
59.
Barley aleurone cells contain two types of vacuoles. Characterization Of lytic organelles by use of fluorescent probes 总被引:10,自引:1,他引:9 下载免费PDF全文
Light microscopy was used to study the structure and function of vacuoles in living protoplasts of barley (Hordeum vulgare cv Himalaya) aleurone. Light microscopy showed that aleurone protoplasts contain two distinct types of vacuole: the protein storage vacuole and a lysosome-like organelle, which we have called the secondary vacuole. Fluorescence microscopy using pH-sensitive fluorescent probes and a fluorogenic substrate for cysteine proteases showed that both protein storage vacuoles and secondary vacuoles are acidic, lytic organelles. Ratio imaging showed that the pH of secondary vacuoles was lower in aleurone protoplasts incubated in gibberellic acid than in those incubated in abscisic acid. Uptake of fluorescent probes into intact, isolated protein storage vacuoles and secondary vacuoles required ATP and occurred via at least two types of vanadate-sensitive, ATP-dependent tonoplast transporters. One transporter catalyzed the accumulation of glutathione-conjugated probes, and another transported probes not conjugated to glutathione. 相似文献
60.
Tai-Boong Uhm Si-Myung Byun Young-Ju Kwon Sang-Bae Han Kwan-Sung Ryu 《Biotechnology letters》1987,9(4):287-290
Summary The three fractions of inulase differing in isoelectric pH were isolated from a strain ofAspergillus
niger by isoelectric focussing and characterized in their temperature stability. These fractions had distinguishable thermal stability. Among them, one fraction (pI 5.2) having main activity showed a high thermal stability comparable to that of the Novozyme 230 (Novo A/S, Denmark) at 60°C. 相似文献