Synthesis of 4-heterocyclyl-hexahydro-8-methoxyfuro[3,2-c]quinolines by Lewis acid catalyzed [4 + 2]cycloaddition reaction

Synthesis of 2-substituted quinoline derivatives by Lewis acid catalyzed [4 + 2]cycloaddition was investigated.     

Regulation of macrophage-specific gene expression by degenerated lipoproteins

The effect of aggregated low-density lipoprotein (agLDL) on cell viability and macrophage-specific gene expression using human peripheral blood monocytes in culture was investigated. AgLDL suppressed activation-induced cell death of phorbol ester-treated macrophages. The inhibition of apoptosis was accompanied by downregulation of apoptosis-promoting proteases, including interleukin-1beta-converting enzyme (ICE) and CPP32 and upregulation of anti-apoptotic cytokine (interleukin-1beta (IL-1beta)). In contrast, macrophage-colony stimulating factor (M-CSF) enhanced cell death of lipid-bearing macrophages, suggesting that the anti-atherogenic action of M-CSF is at least in part mediated through apoptotic elimination of macrophages. Then, we attempted to isolate the genes specifically induced by agLDL in macrophages using a subtraction-based cloning strategy. One of the genes isolated, termed LIG (LDL-inducible gene), encodes a human homolog of E2 ubiquitin-conjugating enzyme. Ubiquitination of multiple intracellular proteins was observed in agLDL-treated macrophages, which coincided with upregulation of LIG. These results suggest that LIG acts as a direct mediator of foam cell formation through polyubiquitination and subsequent degradation of cellular proteins with apoptosis-inducing properties. The regulation of apoptosis by macrophage-specific gene expression may contribute to foam cell formation and atherosclerosis.     

Investigation on specific adsorption of hydrogen on lithium-doped mesoporous silica

This paper reports the synthesis, structure, and hydrogen adsorption property of Li-doped mesoporous silica (MPS) with a 2D hexagonal structure. The Li-doping is achieved by impregnation of the cylindrical mesopores with an ethanol solution of lithium chloride followed by heat treatment. Detailed characterization by solid-state NMR, TG-MS, and FT-IR suggests that, during the heat treatment, lithium chloride reacts with surface ethoxy groups (≡Si-OEt) to form ≡SiOLi groups, while ethyl chloride is released into the gas phase. The hydrogen uptake at 77 K and 1 atm increases from 0.68 wt% for the undoped MPS to 0.81 wt% for Li-doped MPS (Li-MPS). The isosteric heat of adsorption is 4.8 kJ mol⁻¹, which is consistent with the quantum chemistry calculation result (5.12 kJ mol⁻¹). The specific hydrogen adsorption on Li-MPS would be explained by the frontier orbital interaction between HOMO of hydrogen molecules and LUMO of ≡SiOLi. These findings provide an important insight into the development of hydrogen storage materials with specific adsorption sites.     

A forced gas-cooled single-disk window using silicon nitride composite for high power CW millimeter waves

Silicon nitride composite as a candidate of a window material for high power CW (Continuous Wave) millimeter-waves was high power tested especially with a surface cooling by impinging gas nitrogen jets on the single-disk surface. Gas-cooling dramatically suppressed the temperature of the window disk even with gas flow rate of around 100 l/min. With gas cooling of 465l/min., 130kW CW power of HE₁₁ mode could be transmitted through the silicon nitride window with a diameter of 88.9mm. The peak window temperature was completely saturated on 123.6 °C. Without gas-cooling it did not saturate and reached 323 °C during 30 seconds pulse. A possibility of 1MW CW single disk Brewster windows with a forced gas-cooling is discussed, resulting in convinced prospects of the windows with realistic size and thickness.     

Variational inequalities for a system of elliptic–parabolic equations

We create a general framework for mathematical study of variational inequalities for a system of elliptic–parabolic equations. In this paper, we establish a solvability theorem concerning the existence of solutions for the vector-valued elliptic–parabolic variational inequality with time-dependent constraint. Moreover, we give some applications of the system, for example, time-dependent boundary obstacle problem and time-dependent interior obstacle problem.     

Optimal Control Problems for Elliptic–Parabolic Variational Inequalities with Time-Dependent Constraints

In this paper, we study optimal control problems for quasi-linear elliptic–parabolic variational inequalities with time-dependent constraints. We prove the existence of an optimal control that minimizes the nonlinear cost functional. Moreover, we apply our general results to some model problems. In particular, we show the necessary condition of optimal pair for a problem of partial differential equation (PDE) with a non-homogeneous Dirichlet boundary condition.     

Adsorption and dissociation of molecular hydrogen on Pt/CeO2 catalyst in the hydrogen spillover process: A quantum chemical molecular dynamics study

Ultra accelerated quantum chemical molecular dynamics method (UA-QCMD) was used to study the dynamics of the hydrogen spillover process on Pt/CeO₂ catalyst surface for the first time. The direct observation of dissociative adsorption of hydrogen on Pt/CeO₂ catalyst surface as well as the diffusion of dissociative hydrogen from the Pt/CeO₂ catalyst surface was simulated. The diffusion of the hydrogen atom in the gas phase explains the high reactivity observed in the hydrogen spillover process. Chemical changes, change of adsorption states and structural changes were investigated. It was observed that parallel adsorption of hydrogen facilitates the dissociative adsorption leading to hydrogen desorption. Impact with perpendicular adsorption of hydrogen causes the molecular adsorption on the surface, which decelerates the hydrogen spillover. The present study also indicates that the CeO₂ support has strong interaction with Pt catalyst, which may cause an increase in Pt activity as well as enhancement of the metal catalyst dispersions and hence increasing the rate of hydrogen spillover reaction.     

Two-qubit gate of combined single-spin rotation and interdot spin exchange in a double quantum dot

A crucial requirement for quantum-information processing is the realization of multiple-qubit quantum gates. Here, we demonstrate an electron spin-based all-electrical two-qubit gate consisting of single-spin rotations and interdot spin exchange in a double quantum dot. A partially entangled output state is obtained by the application of the two-qubit gate to an initial, uncorrelated state. We find that the degree of entanglement is controllable by the exchange operation time. The approach represents a key step towards the realization of universal multiple-qubit gates.     

Enantioselective Lewis acid-catalyzed Mukaiyama-Michael reactions of acyclic enones. Catalysis by allo-threonine-derived oxazaborolidinones

allo-Threonine-derived O-aroyl-B-phenyl-N-tosyl-1,3,2-oxazaborolidin-5-ones 1g,n catalyze the asymmetric Mukaiyama-Michael reaction of acyclic enones with a trimethylsilyl ketene S,O-acetal in high enantioselectivity. A range of alkenyl methyl ketones is successfully employed as Michael acceptors affording ee values of 85-90% by using 10 mol % of the catalyst. The use of 2,6-diisopropylphenol and tert-butyl methyl ether as additives is found to be essential to achieve high enantioselectivity in these reactions. The effects of the additives are discussed in terms of the retardation of an Si(+)-catalyzed racemic pathway, which seriously deteriorates the enantioselectivity of asymmetric Mukaiyama-Michael reactions. A working model for asymmetric induction is proposed based on correlation between catalyst structures and enantioselectivities.     

Redox-photosensitized chain monomerization of cis-syn-dimer of dimethylthymine; unusual effect of molecular oxygen

$\text{cis}$,$\text{syn}$-Dimer of dimethylthymine was monomerized by means of a chain reaction upon the selective photoexcitation of phenanthrene in aerated acetonitrile in the presence of $\text{p}$-dicyanobenzene. It was found that the dimer forms a CT-complex with O₂.