World War I, international participation and reorganisation of the Japanese chemical community

What kind of "war" did Japanese chemists fight during World War I, and what impact did their experiences have on Japanese chemistry in its aftermath? By focusing on the role of Jōji Sakurai (1858-1939), this paper attempts to answer these questions by looking at the drastic changes in the international relationships of the Japanese chemical community caused by the war. It examines how the Japanese National Research Council was established in 1920 as part of the International Research Council, a product of the reconfiguration of international scientific powers triggered by World War I. This paper argues that Sakurai advocated the establishment of the National Research Council after the American model of wartime mobilisation of science, coordinated fractured Japanese chemical communities for international functions, and facilitated Japan's participation and increased influence in international scientific associations such as the International Union of Pure and Applied Chemistry, established in 1919.     

One-color reversible control of photochromic reactions in a diarylethene derivative: three-photon cyclization and two-photon cycloreversion by a near-infrared femtosecond laser pulse at 1.28 μm

One-color control of colorization/decolorization reactions of diarylethene molecules was attained by using nonresonant high-order multiphoton absorption processes with a near-infrared (NIR) femtosecond laser pulse at 1.28 μm with 35 fs full width at half-maximum (fwhm). The intensity of a rather weak laser pulse (<1 nJ/pulse) can induce the simultaneous three-photon absorption leading to the colorization, while much weaker intensity induces two-photon absorption resulting in the decolorization. The spatial patterning concomitant with higher-order multiphoton absorption processes was also demonstrated.     

Paramagnetic-diamagnetic phase transition accompanied by coordination bond formation-dissociation in the dithiolate complex Na[Ni(pdt)2]·2H2O

Bis(2,3-pyrazinedithiolate)nickel complex Na[Ni(pdt)(2)]·2H(2)O formed one-dimensional stacks of the Ni(pdt)(2) units and showed strong antiferromagnetic interactions along the stacking direction. A first-order phase transition between the paramagnetic and diamagnetic states, which was driven by dimerization of the Ni(pdt)(2) units, accompanied by coordination bond formation, was observed.     

Bond energy analysis revisited and designed toward a rigorous methodology

The present study theoretically revisits and numerically assesses two-body energy decomposition schemes including a newly proposed one. The new decomposition scheme is designed to make the equilibrium bond distance equivalent with the minimum point of bond energies. Although the other decomposition schemes generally predict the wrong order of the C-C bond strengths of C(2)H(2), C(2)H(4), and C(2)H(6), the new decomposition scheme is capable of reproducing the C-C bond strengths. Numerical assessment on a training set of molecules demonstrates that the present scheme exhibits a stronger correlation with bond dissociation energies than the other decomposition schemes do, which suggests that the new decomposition scheme is a reliable and powerful analysis methodology.     

Coupling of two diazotized 3‐aminothieno[3,4‐c]coumarins with aromatic amines

The coupling reactions of two diazotized 3‐aminothieno[3,4‐c]coumarins were investigated. Compounds 1a , 1b both react with sodium nitrite in concentrated sulphuric acid at 0–5°C to give the diazotized intermediates 2 and 3 , the latter resulting from the acid ‐catalyzed hydrolysis of the lactonic ring of 2 . The in situ formed diazonium salts react with aromatic amines ( 4 ) to afford a series of arylazothiophenes dyes in the form of their ammonium sulfate salts. With diazotized aniline, besides the normally expected phenylazothiophene 10 from the reaction with compound 1a , the corresponding product of acid hydrolysis 11 was also isolated. In at least one of the cases, the thienyl diazonium salt 2 undergoes a Gomberg–Bachmann arylation reaction with p‐nitroaniline to give the 2‐arylthiophene 9 . The direct hydrolysis of compounds 1a , 1b by concentrated sulphuric acid and subsequent oxidative dimerization of the primary product of acid hydrolysis led to compound 12 . J. Heterocyclic Chem., (2011).     

Structures and photovoltaic properties of copper oxides/fullerene solar cells

Copper oxide (CuO_x) thin films were produced by spin-coating and electrodeposition methods, and their microstructures and photovoltaic properties were investigated. Thin film solar cells based on the Cu₂O/C₆₀ and CuO/C₆₀ heterojunction or bulk heterojunction structures were fabricated on F-doped or In-doped SnO₂, which showed photovoltaic activity under air mass 1.5 simulated sunlight conditions. Microstructures of the CuO_x thin films were examined by X-ray diffraction and transmission electron microscopy, which indicated the presence of Cu₂O and CuO nanoparticles. The energy levels of the present solar cells were also discussed.     

Adsorption and photodegradation properties of anionic dyes by layered double hydroxides

The adsorption and photodegradation behavior of methyl orange (MO) and fast green (FG) over ZnAl- and MgAl-based layered double hydroxide (LDH) adsorbents have been examined. ZnAl-LDHs were prepared with Zn/Al ratios of 2 to 4 by co-precipitation at pH 8. The ZnAl-LDHs and a commercial MgAl-LDH with a Mg/Al ratio of 3 were evaluated for their ability to adsorb MO and FG and for the photodegradation behavior of these dyes under UV irradiation. Structure analysis of the LDH-dyes-adsorbed complexes revealed that the adsorption produced two types of structures, an intercalation complex for MO and a surface-adsorbed complex for FG. The maximum adsorption of MO on the LDHs was significantly higher (more than tenfold) than FG. Results indicated the adsorption isotherms for the retention of both dyes by ZnAl- and MgAl-LDHs could be fitted to a Freundlich equation, showing a higher affinity for dyes on MgAl-LDH compared to those on ZnAl-LDH. The catalytic degradation ability of dye-LDH complex solid films on a quartz plate was superior to pure dye films under UV irradiation. The FG non-intercalated LDH complexes showed much faster photodegradation under UV irradiation than the MO-intercalated LDH complexes, which pointed to the important role of the LDH materials containing sensitized dyes in enhancing the generation of labile hydroxyl ions from the hydrophilic LDH surface.     

Approximations for nonlinear mappings by the hybrid method in Hilbert spaces

The hybrid method in mathematical programming was introduced by Haugazeau (1968) [1] and he proved a strong convergence theorem for finding a common element of finite nonempty closed convex subsets of a real Hilbert space. Later, Bauschke and Combettes (2001) [2] proposed some condition for a family of mappings (the so-called coherent condition) and established interesting results by the hybrid method. The authors (Nakajo et al., 2009) [10] extended Bauschke and Combettes’s results. In this paper, we introduce a condition weaker than the coherent condition and prove strong convergence theorems which generalize the results of Nakajo et al. (2009) [10]. And we get strong convergence theorems for a family of asymptotically κ-strict pseudo-contractions, a family of Lipschitz and pseudo-contractive mappings and a one-parameter uniformly Lipschitz semigroup of pseudo-contractive mappings.     

Polarization-independent refractive index tuning using gold nanoparticle-stabilized blue phase liquid crystals

Polarization-independent refractive index (RI) modulation can be achieved in blue phase (BP) liquid crystals (LCs) by applying an electric field parallel to the direction of light transmission. One of the problems limiting the achievable tuning range is the field-induced phase transition to the cholesteric phase, which is birefringent and chiral. Here we report the RI modulation capabilities of gold nanoparticle-doped BPs I and II, and we show that field-induced BP-cholesteric transition is suppressed in nanoparticle-doped BP II. Because the LC remains optically isotropic even at high applied voltages, a larger RI tuning range can be achieved.     

Intracellular protein labeling with prodrug-like probes using a mutant β-lactamase tag

Intracellular protein labeling with small molecular probes that do not require a washing step for the removal of excess probe is greatly desired for real-time investigation of protein dynamics in living cells. Successful labeling of proteins on the cell membrane has been performed using mutant β-lactamase tag (BL-tag) technology. In the present study, intracellular protein labeling with novel cell membrane permeable probes based on β-lactam prodrugs is described. The prodrug-based probes quickly permeated the plasma membranes of living mammalian cells, and efficiently labeled intracellular proteins at low probe concentrations. Because these cell-permeable probes were activated only inside cells, simultaneous discriminative labeling of intracellular and cell surface BL-tag fusion proteins was attained by using cell-permeable and impermeable probes. Thus, this technology enables adequate discrimination of the location of proteins labeled with the same protein tag, in conjunction with different color probes, by dual-color fluorescence. Moreover, the combination of BL-tag technology and the prodrug-based probes enabled the labeling of target proteins without requiring a washing step, owing to the efficient entry of probes into cells and the fast covalent labeling achieved with BL-tag technology after bioactivation. This prodrug-based probe design strategy for BL-tags provides a simple experimental procedure with application to cellular studies with the additional advantage of reduced stress to living cells.