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261.
Young Ki Lee Wonhee Hur Sung Won Lee Sung Woo Hong Sung Woo Kim Jung Eun Choi Seung Kew Yoon 《Experimental & molecular medicine》2014,46(2):e77
14-3-3ζ is related to many cancer survival cellular processes. In a previous study, we showed that silencing 14-3-3ζ decreases the resistance of hepatocellular carcinoma (HCC) to chemotherapy. In this study, we investigated whether silencing 14-3-3ζ affects the radioresistance of cancer stem-like cells (CSCs) in HCC. Knockdown of 14-3-3ζ decreased cell viability and the number of spheres by reducing radioresistance in CSCs after γ-irradiation (IR). Furthermore, the levels of pro-apoptotic proteins were upregulated in CSCs via silencing 14-3-3ζ after IR. These results suggest that 14-3-3ζ knockdown enhances radio-induced apoptosis by reducing radioresistance in liver CSCs. 相似文献
262.
Jacqueline E. Cloud Dr. Yonglong Wang Tara S. Yoder Lauren W. Taylor Prof. Yongan Yang 《Angewandte Chemie (International ed. in English)》2014,53(52):14527-14532
The synthesis of colloidal nanocrystals (NCs) of lithiated group 14 elements (Z=Si, Ge, and Sn) is reported, which are Li4.4Si, Li3.75Si, Li4.4Ge, and Li4.4Sn. LixZ compounds are highly reactive and cannot be synthesized by existing methods. The success relied on separating the surface protection from the crystal formation and using a unique passivating ligand. Bare LixZ crystals were first produced by milling elemental Li and Z in an argon‐filled jar. Then, under the assistance of additional milling, hexyllithium was added to passivate the freshly generated LixZ NCs. This ball‐milling‐assisted surface protection method may be generalized to similar systems, such as NaxZ and KxZ. Moreover, Li4.4Si and Li4.4Ge NCs were conformally encapsulated in carbon fibers, providing great opportunities for studying the potential of using LixZ to mitigate the volume‐fluctuation‐induced poor cyclability problem confronted by Z anodes in lithium‐ion batteries. 相似文献
263.
Shan Jin Manman Zhou Xi Kang Xiaowu Li Wenjun Du Xiao Wei Shuang Chen Dr. Shuxin Wang Prof. Manzhou Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):3919-3923
The high-dimensional (that is, three-dimensional (3D)) assembly of nanomaterials is an effective means of improving their properties; however, achieving this assembly at the atomic level remains challenging. Herein, we obtained a novel nanocluster, [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl (Dppp=1,3-bis(diphenylphosphino)propane) showing a 3D octameric assembly mode involving the kernel penetration of eight complete icosahedral Au@Ag10Au2 units for the first time. The atomically precise structure was determined by single-crystal X-ray diffraction, and further confirmed by thermogravimetric analysis, X-ray photoelectron spectroscopy, and electrospray ionization mass spectrometry measurements. Furthermore, ligand-induced transformation prompted the conversion of [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl, with complete octameric fusion into [Au8Ag55(Dppp)4(C6H11S)34][BPh4]2, with incomplete octameric fusion. These observations will hopefully facilitate further research on the assembly of M13 nanobuilding blocks. 相似文献
264.
265.
Shan Jin Manman Zhou Xi Kang Xiaowu Li Wenjun Du Xiao Wei Shuang Chen Shuxin Wang Manzhou Zhu 《Angewandte Chemie (International ed. in English)》2020,59(10):3891-3895
The high‐dimensional (that is, three‐dimensional (3D)) assembly of nanomaterials is an effective means of improving their properties; however, achieving this assembly at the atomic level remains challenging. Herein, we obtained a novel nanocluster, [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl (Dppp=1,3‐bis(diphenylphosphino)propane) showing a 3D octameric assembly mode involving the kernel penetration of eight complete icosahedral Au@Ag10Au2 units for the first time. The atomically precise structure was determined by single‐crystal X‐ray diffraction, and further confirmed by thermogravimetric analysis, X‐ray photoelectron spectroscopy, and electrospray ionization mass spectrometry measurements. Furthermore, ligand‐induced transformation prompted the conversion of [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl, with complete octameric fusion into [Au8Ag55(Dppp)4(C6H11S)34][BPh4]2, with incomplete octameric fusion. These observations will hopefully facilitate further research on the assembly of M13 nanobuilding blocks. 相似文献
266.
Dr. Diego Carnevale Marcel Hollenstein Prof. Geoffrey Bodenhausen 《Chemphyschem》2020,21(10):1044-1051
The isotopic enrichment of nucleic acids with nitrogen-15 is often carried out by solid-phase synthesis of oligonucleotides using phosphoramidite precursors that are synthetically demanding and expensive. These synthetic challenges, combined with the overlap of chemical shifts, explain the lag of nitrogen-15 NMR studies of nucleic acids behind those of proteins. For the structural characterization of DNA and RNA-related systems, new NMR methods that exploit the naturally occurring 99.9 % abundant nitrogen-14 isotope are therefore highly desirable. In this study, we have investigated nitrogen-14 spectra of self-assembled quartets based on the nucleobase guanine in the solid state by means of magic-angle spinning NMR spectroscopy. The network of dipolar proton–nitrogen couplings between neighboring stacked purine units is probed by 2D spectra based on 1H→14N→1H double cross-polarization. Interplane dipolar contacts are identified between the stacked G quartets. The assignment is supported by density functional theory (DFT) calculations of the anisotropic chemical shifts and quadrupolar parameters. The experimental spectra are fully consistent with internuclear distances obtained in silico. Averaging of chemical shifts due to internal motions can be interpreted by semiempirical calculations. This method can easily be extended to synthetic G quartets based on nucleobase or nucleoside analogs and potentially to oligonucleotides. 相似文献
267.
Single atom catalysts (SACs) have attracted much attention in recent years. As an essential group in SACs, M−X−C (X=nonmetallic element) materials have been demonstrated to be efficient in many reactions. However, identifying the active sites on M−X−C, especially under working conditions, is still challenging, which is crucial for chemists to further understand the mechanism underlying the reaction and better design proper SACs for specific reactions. Herein, the types and characterization of M−X−C are comprehensively summarized and discussed in this review. In addition to the basic information above, the challenges and opportunities remaining in this field will be also proposed to present a perspective to the research on the next step. 相似文献
268.
Ryoma Masuda Yuuya Kawasaki Kazunobu Igawa Yoshiyuki Manabe Hiroshi Fujii Nobuo Kato Katsuhiko Tomooka Junko Ohkanda 《化学:亚洲杂志》2020,15(6):742-747
Mid‐sized molecules have emerged as an attractive chemical space and potentially provide a robust basis for the development of synthetic agents to control intracellular protein interactions. However, the limited cell permeability and chemical tractability of such agents remain to be addressed. We envisioned that target‐templated synthesis of such mid‐sized molecules might provide a solution. Here, we exploited a copper‐free Huisgen cycloaddition for template synthesis using a peptide fragment containing a 4,8‐diazacyclononyne (DACN) moiety and an azide‐containing fusicoccin derivative in the presence or absence of recombinant 14‐3‐3ζ protein in vitro. Time‐course changes in the yield of products demonstrated that the reaction was accelerated in the presence of 14‐3‐3 and one of the regioisomers was generated predominantly, supporting the template effect. 相似文献
269.
基于HL-2M装置对时序精度的要求,参考ITER的设计方案,设计了基于精确时间协议(PTP)的HL-2M分布式时间通讯网络,使HL-2M装置的时钟同步和事件触发的精度从微秒级提高到亚微秒级,最终优于100ns. 相似文献
270.
A short retrospection is given on the development of M?ssbauer spectroscopy and on the early period of its application to
heterogeneous catalysis in Hungary. Besides the historical view, we present results of recent studies of a latest application
on a nanosystem. Namely, catalytic centres in Fe-ZSM-5 are studied by in situ spectroscopy, the results are correlated with
parallel activity measurements in the decomposition of N2O. Changes in paramagnetic relaxation features are interpreted as the effects of Fe2+/Fe3+ interconversions. From the analysis, the dominance of the mononuclear species is suggested at lower temperature (620 K).
The dinuclear Fe(3+)
framework-O-Fe(2+)
extra-framework species play probably more expressed role at higher temperatures (∼ 770 K) in the decompositon of nitrous oxide. 相似文献