Spectral methods for growth curve clustering

Central European Journal of Operations Research - The growth curve clustering problem is analyzed and its connection with the spectral relaxation method is described. For a given set of growth...     

Electron tomography of Nafion ionomer coated on Pt/carbon black in high utilization electrode for PEFCs

To confirm the superiority of newly developed electrocatalyst layer (ECL) for polymer electrolyte fuel cells, three-dimensional dispersion states of Nafion ionomer in Pt/carbon black agglomerates were analyzed by electron tomography based on multiple TEM images taken at different tilt angles. Uniform distribution of the ionomer has been first observed, proving the high catalyst utilization in the new ECL distinctive from that of the conventional one.     

Metal filament growth in electrically conductive polymers for nonvolatile memory application

Solution processable polymers that can reproducibly form metal filament by applying voltage are investigated for nonvolatile memory application. Up to present, the understanding of materials enabling to make the metal filament has not been well-documented and the vacuum deposition methods were dominantly used in device fabrication. After screening various polymers, we found that only the polymers having two functionalities, the presence of strongly coordinating heteroatom (S or N) with metal ions and the electrical conductivity, showed the reproducible filament formation behavior. Among the polymers screened, the regiorandom poly(3-hexylthiophene) showed the best switching endurance over 30,000 write-read-erase-read cycles without any switching failure.     

Conformations and electronic structures of axially coordinated fullerene-porphyrin-fullerene triad (C60CHCOO)2-Sn(IV) porphyrin

The conformational (cis and trans) stability and electronic structures of (C(60)CHCOO)(2)-Sn(IV) porphyrin, recently synthesized as a novel fullerene-porphyrin-fullerene triad linked by metal axial coordination, have been studied by ab initio calculations. The cis conformer was found to be slightly more stable than the trans by 1.38 kcal/mol in the neutral compound. Upon the addition of an electron to the triad, the relative stability of the cis conformer was found to be higher (3.29 kcal/mol) than that in the neutral one. From the investigation of frontier molecular orbitals, for the cis conformer, it was found that the electrons are localized in HOMO of the porphyrin, while the electrons are localized in LUMO of the syn-fullerene. For the trans conformer, it was found that the electrons are localized in HOMO of the porphyrin, while the electrons are localized in LUMO of one of the two fullerene moieties, and the electrons are localized in LUMO2 of the other fullerene moiety, but the LUMO and LUMO2 have the same orbital energy. Thus, the PET may take place unidirectionally in the cis conformer from the porphyrin to the syn-fullerene, while it is bidirectional from the porphyrin to both of the fullerene moieties.     

Gel-Electrophoresis and Subsequent Optical Emission 15N Analysis to Identify 15N-Labelled Protein Fractions

Abstract

A combined procedure to detect of ¹⁵N/¹⁴N isotope ratios by emission spectrometric analysis after starch gel-electrophoresis was developed. ¹⁵N-labelled proteins of human serum were used to optimise this method. Electrophorised gel slices with protein fractions were directly digested for subsequent isotope analysis. This method is proposed for use in routine analysis for clinical application.     

KRIBB11 Induces Apoptosis in A172 Glioblastoma Cells via MULE-Dependent Degradation of MCL-1

KRIBB11, an HSF1 inhibitor, was shown to sensitize various types of cancer cells to treatment with several anticancer drugs. However, the exclusive effects of KRIBB11 in preventing the growth of glioblastoma cells and the related mechanisms have not been elucidated yet. Herein, we aimed to examine the potential of KRIBB11 as an anticancer agent for glioblastoma. Using MTT and colony formation assays and Western blotting for c-PARP, we demonstrated that KRIBB11 substantially inhibits the growth of A172 glioma cells by inducing apoptosis. At the molecular level, KRIBB11 decreased anti-apoptotic protein MCL-1 levels, which was attributable to the increase in MULE ubiquitin ligase levels. However, the constitutive activity of HSF1 in A172 cells was not influenced by the exclusive treatment with KRIBB11. Additionally, based on cycloheximide chase assay, we found that KRIBB11 markedly retarded the degradation of MULE. In conclusion, stabilization of MULE upon KRIBB11 treatment is apparently an essential step for degradation of MCL-1 and the subsequent induction of apoptosis in A172 cells. Our results have expanded the knowledge on molecular pathways controlled by KRIBB11 and could be potentially effective for developing an inhibitory therapeutic strategy for glioblastoma.     

Polar oxide substrates for graphene growth: A first-principles investigation of graphene on MgO(111)

Given the recent excitement over the truly two-dimensional carbon “super” material – graphene, there is now much effort and focus on the various possibilities of engineering the band gap of graphene for its device applications. One possible and promising route will be to grow graphene directly on some non-metallic substrates. In this paper, we address the atomic and electronic structure of various graphene structures on the polar MgO(111) using first-principles density-functional theory (DFT) calculations. We find that graphene generally interacts strongly with the O-terminated polar oxide surface, forming strong chemical bonds, inferred from both energetics and detailed density-of-states analysis. We compare our theoretical findings with available experimental results, offering a possible direction for future band gap engineering of graphene on such oxide substrates.