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91.
92.
Md Ariful Islam Syeda Ridita Sharif HyunSook Lee Dae-Hyun Seog Il Soo Moon 《Experimental & molecular medicine》2015,47(8):e177
N-acetylglucosamine kinase (GlcNAc kinase or NAGK) is a ubiquitously expressed enzyme in mammalian cells. Recent studies have shown that NAGK has an essential structural, non-enzymatic role in the upregulation of dendritogenesis. In this study, we conducted yeast two-hybrid screening to search for NAGK-binding proteins and found a specific interaction between NAGK and dynein light-chain roadblock type 1 (DYNLRB1). Immunocytochemistry (ICC) on hippocampal neurons using antibodies against NAGK and DYNLRB1 or dynein heavy chain showed some colocalization, which was increased by treating the live cells with a crosslinker. A proximity ligation assay (PLA) of NAGK-dynein followed by tubulin ICC showed the localization of PLA signals on microtubule fibers at dendritic branch points. NAGK-dynein PLA combined with Golgi ICC showed the colocalization of PLA signals with somal Golgi facing the apical dendrite and with Golgi outposts in dendritic branch points and distensions. NAGK-Golgi PLA followed by tubulin or DYNLRB1 ICC showed that PLA signals colocalize with DYNLRB1 at dendritic branch points and at somal Golgi, indicating a tripartite interaction between NAGK, dynein and Golgi. Finally, the ectopic introduction of a small peptide derived from the C-terminal amino acids 74–96 of DYNLRB1 resulted in the stunting of hippocampal neuron dendrites in culture. Our data indicate that the NAGK-dynein-Golgi tripartite interaction at dendritic branch points functions to regulate dendritic growth and/or branching. 相似文献
93.
CongZhan Liu YiFei Zhang XuFang Li XueFeng Lu Zhi Chang ZhengWei Li AiMei Zhang YongJie Jin HuiMing Yu Zhao Zhang MinXue Fu YiBao Chen JianFeng Ji YuPeng Xu JingKang Deng RenCheng Shang GuoQing Liu FangJun Lu ShuangNan Zhang YongWei Dong TiPei Li Mei Wu YanGuo Li HuanYu Wang BoBing Wu YongJie Zhang Zhi Zhang ShaoLin Xiong Yuan Liu Shu Zhang HongWei Liu YiJung Yang Fan Zhang 《中国科学:物理学 力学 天文学(英文版)》2020,(4):20-34
The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments. 相似文献
94.
95.
Facile preparation of boronic acid‐functionalized magnetic nanoparticles with a high capacity and their use in the enrichment of cis‐diol‐containing compounds from plasma 下载免费PDF全文
Jin Du Maofang He Xiaomeng Wang Hua Fan Yinmao Wei 《Biomedical chromatography : BMC》2015,29(2):312-320
The use of bronate affinity adsorbents is a new separation method that appeared recently with great potential for specific extraction of cis‐diol‐containing compounds. In this work,a new strategy for the facile construction of boronic acid‐functionalized Fe3O4 magnetic nanoparticles (Fe3O4@FPBA MNPs) with a high capacity was described. The extraction capacity of the Fe3O4@FPBA MNPs was determined to be 66.0 ± 2.7 µmol/g for catechol and 80.6 ± 2.0 µmol/g for dopamine, being higher than that for the reported methods. The Fe3O4@FPBA MNPs were used to extract four cis‐diol drugs: caffeic acid isopropyl ester, caffic acid bornyl ester, isopropyl 3‐(3,4‐dihydroxyphenyl)‐2‐hydroxypropanoate and 3‐(3, 4‐dihydroxyphenyl)‐2‐hydroxylpropionic acid – from the spiked rabbit plasma, and the recoveries of four drugs were between 87.29 and104.37% with relative standard deviations ranging from 1.34 to 8.81%. Under the most favorable conditions, the solid‐phase extraction combined with HPLC‐UV for the analysis of four drugs in plasma could eliminate interferences from endogenous components of the biological fluids and exhibited sufficient precision and accuracy. These results showed that the prepared Fe3O4@FPBA MNPs were qualified for efficiently enriching and determining the trace cis‐diol substances from biological samples. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
96.
97.
A New Concept for Obtaining SnO2 Fiber‐in‐Tube Nanostructures with Superior Electrochemical Properties 下载免费PDF全文
Young Jun Hong Ji‐Wook Yoon Prof. Jong‐Heun Lee Prof. Yun Chan Kang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):371-376
Tin oxide (SnO2) nanotubes with a fiber‐in‐tube structure have been prepared by electrospinning and the mechanism of their formation has been investigated. Tin oxide‐carbon composite nanofibers with a filled structure were formed as an intermediate product, which were then transformed into SnO2 nanotubes with a fiber‐in‐tube structure during heat treatment at 500 °C. Nanofibers with a diameter of 85 nm were found to be located inside hollow nanotubes with an outer diameter of 260 nm. The prepared SnO2 nanotubes had well‐developed mesopores. The discharge capacities of the SnO2 nanotubes at the 2nd and 300th cycles at a current density of 1 A g?1 were measured as 720 and 640 mA h g?1, respectively, and the corresponding capacity retention measured from the 2nd cycle was 88 %. The discharge capacities of the SnO2 nanotubes at incrementally increased current densities of 0.5, 1.5, 3, and 5 A g?1 were 774, 711, 652, and 591 mA h g?1, respectively. The SnO2 nanotubes with a fiber‐in‐tube structure showed superior cycling and rate performances compared to those of SnO2 nanopowder. The unique structure of the SnO2 nanotubes with a fiber@void@tube configuration improves their electrochemical properties by reducing the diffusion length of the lithium ions, and also imparts greater stability during electrochemical cycling. 相似文献
98.
Redox Communication within Multinuclear Iron–Sulfur Complexes Related to Electronic Interplay in the Active Site of [FeFe]Hydrogenase 下载免费PDF全文
Kai‐Ti Chu Dr. Yu‐Chiao Liu Yi‐Lan Huang Dr. Gene‐Hsiang Lee Dr. Mei‐Chun Tseng Prof. Ming‐Hsi Chiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(18):6852-6861
The one‐electron oxidations of a Fe2 complex lead to the formation of a persistent metal‐stabilized thiyl radical Fe2 species, mixed‐valent Fe4, and Fe8 complexes. The unpaired spin in the Fe2 radical species delocalizes over the Fe2 and the aromatic dithiolate, mostly on the terminal sulfur. The subsequent dimerization of the singly oxidized Fe2 to the Fe4 retains the partial thiyl radical character. For an analogue with less steric hindrance, the π–π stacking interaction between the dithiolato aromatic rings induces generation of the Fe8, in which process electronic structures of the species are modulated through reducing the thiyl radical to the thiolate. Electronic reorganization repeats when the Fe8 is converted to Fe4. Electronic interplay in the complexes decreases the energy gap of frontier MOs and buffers electronic impacts upon redox events. Easier accessible redox potentials and increased stability of the species are facilitated. The results demonstrate that electronic versatility of the benzenedithiolate exerts pronounced influences on electronic and coordination structure of the metal complexes. 相似文献
99.
Solid‐state 31P NMR investigation on the status of guanine nucleotides in paclitaxel‐stabilized microtubules 下载免费PDF全文
Ga Hyang Lee Su Young Oh Kwon Joo Yeo Taslima Ferdous Meeyeon Cho Younkee Paik 《Magnetic resonance in chemistry : MRC》2015,53(5):330-336
Microtubule dynamics is a target for many chemotherapeutic drugs. In order to understand the biochemical effects of paclitaxel on the GTPase activity of tubulin, the status of guanine nucleotides in microtubules was investigated by 31P cross‐polarization magic angle spinning (CPMAS) NMR. Microtubules were freshly prepared in vitro in the presence of paclitaxel and then lyophilized in sucrose buffer for solid‐state NMR experiments. A 31P CPMAS NMR spectrum with the SNR of 25 was successfully acquired from the lyophilized microtubule sample. The broadness of the 31P spectral lines in the spectrum indicates that the molecular environments around the guanine nucleotides inside tubulin may not be as crystalline as reported by many diffraction studies. Deconvolution of the spectrum into four spectral components was carried out in comparison with the 31P NMR spectra obtained from five control samples. The spectral analysis suggested that about 13% of the nucleotides were present as GTP and 37% as GDP in the β‐tubulin (E‐site) of the microtubules. It was found that most of the GDPs were present as GDP‐Pi complex in the microtubules, which seems to be one of the effects of paclitaxel binding. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
100.
From single‐chain folding to polymer nanoparticles via intramolecular quadruple hydrogen‐bonding interaction 下载免费PDF全文
Fei Wang Hongting Pu Ming Jin Haiyan Pan Zhihong Chang Decheng Wan Jiang Du 《Journal of polymer science. Part A, Polymer chemistry》2015,53(15):1832-1840
Single‐chain folding via intramolecular noncovalent interaction is regarded as a facile mimicry of biomacromolecules. Single‐chain folding and intramolecular crosslinking is also an effective method to prepare polymer nanoparticles. In this study, poly(methyl methacrylate‐co?2‐ureido‐5‐deazapterines functionalized ethylene methacrylate) (P(MMA‐co‐EMA‐DeAP)) is synthesized via free radical polymerization. The single‐chain folding of P(MMA‐co‐EMA‐DeAP) and the formation of the nanoparticles in diluted solution (concentration <0.005 mg/mL) are achieved via supramolecular interaction and intramolecular collapsing during the disruption‐reformation process of the hydrogen bonding triggered by water. The size and the morphology of the nanoparticles are characterized by dynamic light scattering, transmission electron microscope, and atomic force microscope. The results show that the size of the nanoparticles depends on the molecular weight of the polymer and the loading of 2‐ureido‐5‐deazapterines functionalized ethylene methacrylate (EMA‐DeAP) on the polymer backbone. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1832–1840 相似文献