High‐Quality Three‐Dimensional Nanoporous Graphene

We report three‐dimensional (3D) nanoporous graphene with preserved 2D electronic properties, tunable pore sizes, and high electron mobility for electronic applications. The complex 3D network comprised of interconnected graphene retains a 2D coherent electron system of massless Dirac fermions. The transport properties of the nanoporous graphene show a semiconducting behavior and strong pore‐size dependence, together with unique angular independence. The free‐standing, large‐scale nanoporous graphene with 2D electronic properties and high electron mobility holds great promise for practical applications in 3D electronic devices.     

An M12(L1)12(L2)12 Cantellated Tetrahedron: A Case Study on Mixed‐Ligand Self‐Assembly

In the self‐assembly of Pd^II ions and two different, but similarly shaped, ligands ( 1 and 2 ), neither random mixing nor self‐sorting of the two ligands into two unmixed structures was observed. Instead a mixed, yet sorted, Pd₁₂( 1 )₁₂( 2 )₁₂ cantellated tetrahedron (and its pseudoisomer) was selectively formed, thus revealing a fine example of intramolecular self‐sorting. A case study showed that a homothetic ratio of >2 is necessary to observe cantellated tetrahedra.     

Symmetry-itemized enumeration of RS-stereoisomers of allenes. I. The fixed-point matrix method of the USCI approach combined with the stereoisogram approach

After the RS-stereoisomeric group \(\mathbf{D}_{2d\widetilde{\sigma }\widehat{I}}\) of order 16 has been defined by starting point group \(\mathbf{D}_{2d}\) of order 8, the isomorphism between \(\mathbf{D}_{2d\widetilde{\sigma }\widehat{I}}\) and the point group \(\mathbf{D}_{4h}\) of order 16 is thoroughly discussed. The non-redundant set of subgroups (SSG) of \(\mathbf{D}_{2d\widetilde{\sigma }\widehat{I}}\) is obtained by referring to the non-redundant set of subgroups of \(\mathbf{D}_{4h}\) . The coset representation for characterizing the orbit of the four positions of an allene skeleton is clarified to be \(\mathbf{D}_{2d\widetilde{\sigma }\widehat{I}}(/\mathbf{C}_{s\widetilde{\sigma }\widehat{I}})\) , which is closely related to the \(\mathbf{D}_{4h}(/\mathbf{C}_{2v}^{\prime \prime \prime })\) . According to the unit-subduced-cycle-index (USCI) approach (Fujita, Symmetry and combinatorial enumeration of chemistry. Springer, Berlin 1991), the subduction of \(\mathbf{D}_{2d\widetilde{\sigma }\widehat{I}}(/\mathbf{C}_{s\widetilde{\sigma }\widehat{I}})\) is examined so as to generate unit subduced cycle indices with chirality fittingness (USCI-CFs). Then, the fixed-point matrix method of the USCI approach is applied to the USCI-CFs. Thereby, the numbers of quadruplets are calculated in an itemized fashion with respect to the subgroups of \(\mathbf{D}_{2d\widetilde{\sigma }\widehat{I}}\) . After the subgroups of \(\mathbf{D}_{2d\widetilde{\sigma }\widehat{I}}\) are categorized into types I–V, type-itemized enumeration of quadruplets is conducted to illustrate the versatility of the stereoisogram approach.     

Exploiting the Potential of Meroterpenoid Cyclases to Expand the Chemical Space of Fungal Meroterpenoids

Fungal meroterpenoids are a diverse group of hybrid natural products with impressive structural complexity and high potential as drug candidates. In this work, we evaluate the promiscuity of the early structure diversity-generating step in fungal meroterpenoid biosynthetic pathways: the multibond-forming polyene cyclizations catalyzed by the yet poorly understood family of fungal meroterpenoid cyclases. In total, 12 unnatural meroterpenoids were accessed chemoenzymatically using synthetic substrates. Their complex structures were determined by 2D NMR studies as well as crystalline-sponge-based X-ray diffraction analyses. The results obtained revealed a high degree of enzyme promiscuity and experimental results which together with quantum chemical calculations provided a deeper insight into the catalytic activity of this new family of non-canonical, terpene cyclases. The knowledge obtained paves the way to design and engineer artificial pathways towards second generation meroterpenoids with valuable bioactivities based on combinatorial biosynthetic strategies.     

Bucillamine Inhibits UVB-Induced MAPK Activation and Apoptosis in Human HaCaT Keratinocytes and SKH-1 Hairless Mouse Skin

Ultraviolet B (UVB) radiation is known as a culprit in skin carcinogenesis. We have previously reported that bucillamine (N-[2-mercapto-2-methylpropionyl]-L-cysteine), a cysteine derivative with antioxidant and anti-inflammatory capacity, protects against UVB-induced p53 activation and inflammatory responses in mouse skin. Since MAPK signaling pathways regulate p53 expression and activation, here we determined bucillamine effect on UVB-mediated MAPK activation in vitro using human skin keratinocyte cell line HaCaT and in vivo using SKH-1 hairless mouse skin. A single low dose of UVB (30 mJ cm⁻²) resulted in increased JNK/MAPK phosphorylation and caspase-3 cleavage in HaCaT cells. However, JNK activation and casaspe-3 cleavage were inhibited by pretreatment of HaCaT cells with physiological doses of bucillamine (25 and 100 µm ). Consistent with these results, bucillamine pretreatment in mice (20 mg kg⁻¹) inhibited JNK/MAPK and ERK/MAPK activation in skin epidermal cells at 6–12 and 24 h, respectively, after UVB exposure. Moreover, bucillamine attenuated UVB-induced Ki-67-positive cells and cleaved caspase-3-positive cells in mouse skin. These findings demonstrate that bucillamine inhibits UVB-induced MAPK signaling, cell proliferation and apoptosis. Together with our previous report, we provide evidence that bucillamine has a photoprotective effect against UV exposure.     

In Vitro and In Silico Study of Analogs of Plant Product Plastoquinone to Be Effective in Colorectal Cancer Treatment

Plants have paved the way for the attainment of molecules with a wide-range of biological activities. However, plant products occasionally show low biological activities and/or poor pharmacokinetic properties. In that case, development of their derivatives as drugs from the plant world has been actively performed. As plant products, plastoquinones (PQs) have been of high importance in anticancer drug design and discovery; we have previously evaluated and reported the potential cytotoxic effects of a series of PQ analogs. Among these analogs, PQ2, PQ3 and PQ10 were selected for National Cancer Institute (NCI) for in vitro screening of anticancer activity against a wide range of cancer cell lines. The apparent superior anticancer potency of PQ2 on the HCT-116 colorectal cancer cell line than that of PQ3 and PQ10 compared to other tested cell lines has encouraged us to perform further mechanistic studies to enlighten the mode of anti-colorectal cancer action of PQ2. For this purpose, its apoptotic effects on the HCT-116 cell line, DNA binding capacity and several crucial pharmacokinetic properties were investigated. Initially, MTT assay was conducted for PQ2 at different concentrations against HCT-116 cells. Results indicated that PQ2 exhibited significant cytotoxicity in HCT-116 cells with an IC₅₀ value of 4.97 ± 1.93 μM compared to cisplatin (IC₅₀ = 26.65 ± 7.85 μM). Moreover, apoptotic effects of PQ2 on HCT-116 cells were investigated by the annexin V/ethidium homodimer III staining method and PQ2 significantly induced apoptosis in HCT-116 cells compared to cisplatin. Based on the potent DNA cleavage capacity of PQ2, molecular docking studies were conducted in the minor groove of the double helix of DNA and PQ2 presented a key hydrogen bonding through its methoxy moiety. Overall, both in vitro and in silico studies indicated that effective, orally bioavailable drug-like PQ2 attracted attention for colorectal cancer treatment. The most important point to emerge from this study is that appropriate derivatization of a plant product leads to unique biologically active compounds.     

Three-dimensional visualization of columnar vortices in rotating Rayleigh–Bénard convection

Journal of Visualization -  To enrich the three-dimensional experimental details of vortex structures in rotating Rayleigh–Bénard convection, we established a technique...     

Development and application of high strength ternary boride base cermets

Reaction boronizing sintering is a novel strategy to form a ternary boride coexisting with a metal matrix in a cermet during liquid phase sintering. This new sintering technique has successfully developed world first ternary boride base cermets with excellent mechanical properties such as Mo₂FeB₂, Mo₂NiB₂ and WCoB base ones.In these cermets Mo₂FeB₂ and Mo₂NiB₂ base ones consist of a tetragonal M₃B₂ (M: metal)-type complex boride as a hard phase and a transition metal base matrix. The cermets have already been applied to wear resistant applications such as injection molding machine parts, can making tools, and hot copper extruding dies, etc.This paper focuses on the characteristics, effects of the additional elements on the mechanical properties and structure, and practical applications of the ternary boride base cermets.     

Waveform control for magnetic testers using a quasi-Newton method

A nonlinear iterative learning algorithm is proposed to make a voltage waveform in the secondary coil sinusoidal in this paper. The algorithm employs a globally convergent Jacobian-free quasi-Newton type solver that has a BFGS-like structure. This method functions well, and it is demonstrated using typical soft magnetic materials.