187 research outputs found

    Chemical, Thermal, and Light-Driven Reduction of Graphene Oxide: Approach to Obtain Graphene and its Functional Hybrids

    Get PDF
    The alternative synthetic route of graphene (G) is presented. At first, graphite is oxidized to graphite oxide, which is dispersed in water to form graphene oxide (GO). GO can be reduced to rGO or G. GO being negatively charged can be used to obtain organic functionalized GO or hybrid of GO, reduction of which finally result in the formation of G-based hybrids. The reduction of GO or GO hybrid can be accomplished by light irradiation, thermal annealing, or by treating with reducing agents. The chemical changed from graphite to GO and GO to rGO can be monitored by surface analysis, microscopic investigation, and various spectroscopic methods

    Triphenyl{(E)-4-[4-(phenyldiazenyl)phenyl]-4H-1,2,4-triazol-1-yl}boron

    Get PDF
    In the title compound, C32H26BN5 or [(C14H11N5)B(C6H5)3], the B atom is approximately tetra­hedrally coordinated. The diazo unit is in a trans conformation, which is generally more stable than a cis one for aromatic azo compounds. The crystal structure features very weak C—H⋯π inter­actions. The dihedral angles between the central benzene ring and the terminal rings in the heterocycle are 62.64, 73.54 and 61.60°

    Dichlorido[1-(8-quinolylimino­meth­yl)-2-naphtholato]iron(III)

    Get PDF
    The FeIII ion in the title complex, [FeCl2(C20H13N2O)], has a distorted square-pyramidal coordination formed by one O atom and two N atoms from a tridentate 1-(8-quinolylimino­meth­yl)-2-naphtholate ligand and two Cl atoms. In the crystal structure, mol­ecules form a column structure along the a axis through π–π stacking inter­actions, with centroid–centroid distances of 3.657 (1) and 3.818 (2) Å. Weak C—H⋯Cl inter­actions are observed between the columns

    Bis(1H-imidazole-κN 3){2,2′-[propane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato-κ4 O,N,N′,O′}iron(III) perchlorate

    Get PDF
    The title compound, [Fe(C17H16N2O2)(C3H4N2)2]ClO4, consists of monomeric [Fe(salmen)(HIm)2]+ cations {salmen is the 2,2′-[propane-1,2-diylbis(nitrilo­methyl­idyne)]diphen­olate dianion and HIm is 1H-imiazole} and perchlorate anions. In the cation, the Fe3+ ion is octahedrally coordinated by two N atoms and two O atoms from a tetra­dentate salmen anion and two N atoms from two Him mol­ecules. These ligands are coordinated to the iron ion in a direction perpendicular to the [Fe(salmen)]+ coordination plane. The benzene ring planes in the salmen ligands are oriented nearly parallel to one another inter­molecularly [dihedral angle = 6.36 (3)°]. The dihedral angle between the mean planes through the imidazole rings in the cation is 76.9 (2)°. In the crystal, N—H⋯O inter­actions link the mol­ecules into a one-dimensional double chain running along [101] and C—H⋯O inter­actions link the double chains into a two-dimensional network, running parallel to the ac plane

    Programmable spin-state switching in a mixed-valence spin-crossover iron grid

    Get PDF
    Photo-switchable systems, such as discrete spin-crossover complexes and bulk iron–cobalt Prussian blue analogues, exhibit, at a given temperature, a bistability between low- and high-spin states, allowing the storage of binary data. Grouping different bistable chromophores in a molecular framework was postulated to generate a complex that could be site-selectively excited to access multiple electronic states under identical conditions. Here we report the synthesis and the thermal and light-induced phase transitions of a tetranucleariron(II) grid-like complex and its two-electron oxidized equivalent. The heterovalent grid is thermally inactive but the spin states of its constituent metal ions are selectively switched using different laser stimuli, allowing the molecule to exist in three discrete phases. Site-selective photo-excitation, herein enabling one molecule to process ternary data, may have major ramifications in the development of future molecular memory storage technologies

    Spin-crossover behaviors in solvated cobalt(II) compounds

    Get PDF
    Two solvated cobalt(ii) terpyridine complexes, [Co(MeO-terpy)2](BF4)2·H2O (1·H2O) and [Co(MeO-terpy)2](BF4)2·acetone (1·acetone) were prepared. Annealing each of these complexes resulted in the formation of two desolvated species, 1 and 1′, respectively. 1·H2O and 1 exhibited two-step and gradual SCO. The compound 1·acetone has high-spin at all temperatures and 1′ undergoes a reverse spin transition due to a phase change

    Overexpression of the JmjC histone demethylase KDM5B in human carcinogenesis: involvement in the proliferation of cancer cells through the E2F/RB pathway.

    Get PDF
    BACKGROUND: Although an increasing number of histone demethylases have been identified and biochemically characterized, their biological functions largely remain uncharacterized, particularly in the context of human diseases such as cancer. We investigated the role of KDM5B, a JmjC histone demethylase, in human carcinogenesis. Quantitative RT-PCR and microarray analyses were used to examine the expression profiles of histone demethylases in clinical tissue samples. We also examined the functional effects of KDM5B on the growth of cancer cell lines treated with small interfering RNAs (siRNAs). Downstream genes and signal cascades induced by KDM5B expression were identified from Affymetrix Gene Chip experiments, and validated by real-time PCR and reporter assays. Cell cycle-dependent characteristics of KDM5B were identified by immunofluorescence and FACS. RESULTS: Quantitative RT-PCR analysis confirmed that expression levels of KDM5B are significantly higher in human bladder cancer tissues than in their corresponding non-neoplastic bladder tissues (P < 0.0001). The expression profile analysis of clinical tissues also revealed up-regulation of KDM5B in various kinds of malignancies. Transfection of KDM5B-specific siRNA into various bladder and lung cancer cell lines significantly suppressed the proliferation of cancer cells and increased the number of cells in sub-G1 phase. Microarray expression analysis indicated that E2F1 and E2F2 are downstream genes in the KDM5B pathway. CONCLUSIONS: Inhibition of KDM5B may affect apoptosis and reduce growth of cancer cells. Further studies will explore the pan-cancer therapeutic potential of KDM5B inhibition.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Minichromosome Maintenance Protein 7 is a potential therapeutic target in human cancer and a novel prognostic marker of non-small cell lung cancer.

    Get PDF
    BACKGROUND: The research emphasis in anti-cancer drug discovery has always been to search for a drug with the greatest antitumor potential but fewest side effects. This can only be achieved if the drug used is against a specific target located in the tumor cells. In this study, we evaluated Minichromosome Maintenance Protein 7 (MCM7) as a novel therapeutic target in cancer. RESULTS: Immunohistochemical analysis showed that MCM7 was positively stained in 196 of 331 non-small cell lung cancer (NSCLC), 21 of 29 bladder tumor and 25 of 70 liver tumor cases whereas no significant staining was observed in various normal tissues. We also found an elevated expression of MCM7 to be associated with poor prognosis for patients with NSCLC (P = 0.0055). qRT-PCR revealed a higher expression of MCM7 in clinical bladder cancer tissues than in corresponding non-neoplastic tissues (P < 0.0001), and we confirmed that a wide range of cancers also overexpressed MCM7 by cDNA microarray analysis. Suppression of MCM7 using specific siRNAs inhibited incorporation of BrdU in lung and bladder cancer cells overexpressing MCM7, and suppressed the growth of those cells more efficiently than that of normal cell strains expressing lower levels of MCM7. CONCLUSIONS: Since MCM7 expression was generally low in a number of normal tissues we examined, MCM7 has the characteristics of an ideal candidate for molecular targeted cancer therapy in various tumors and also as a good prognostic biomarker for NSCLC patients.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
    corecore