Development of a Novel Catalytic Membrane Reactor for Heterogeneous Catalysis in Supercritical CO2

A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO2). The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO2 for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamaldehyde has been successfully carried out with 100% selectivity at 50 °C in 10 MPa (H2: 1 MPa, CO2: 9 MPa) with a flow rate of substrate ranging from 0.05 to 1.0 mL/min

Inner Structure of Cloud Cavity on a Foil Section

Collapsing stage of cloud cavity and resulting violent shock pressure have been investigated by many researchers, because the knowledge of cavitation erosion is of practical importance and the dynamics is one of the most challenging problems in the field of two-phase flow. When a researche Collapsing stage of cloud cavity and resulting violent shock pressure have been investigated by many researchers, because the knowledge of cavitation erosion is of practical importance and the dynamics is one of the most challenging problems in the field of two-phase flow. When a researcher intends to investigate the phenomenon numerically or experimentally, he or she must know the structure of the cloud cavity. The authors investigate cloud cavity, employing an off-axis laser holography system. This paper is a brief report concerning the inner structure of cloud cavity on a foil section

Synthesis of single and multi unit-wall MgB[sub 2] nanotubes by arc plasma in inert liquid via self-curling mechanism

Magnesium diboride (MgB2) is known as a promising superconductor due to its high transmission temperature. Similarly to single-wall carbon nanotube, unique characteristics would be seen if a nanotube structure of MgB2 having a unit-wall of Mg and B atomic bilayer is prepared. However, such MgB2 nanotubes have not ever been synthesized. In this article, formation mechanism of unit-wall MgB2 nanotube is elucidated by molecular mechanics calculation. From the viewpoint of energetic stability, the unit-wall will be curled up to form nanotube structure when MgB2 crystal is disassembled to an isolated unit-wall layer. An experiment using arc plasma in inert liquid was utilized to produce unit-wall MgB2 nanotubes. As a result, a single and multiunit-wall MgB2 nanotube was successfully synthesized. In this reaction field, the arc plasma may play a role to produce isolated MgB2 unit-wall fragment, and the cold cathode surface can contribute to preserve MgB2 nanotube structure

Rapid Suzuki-Miyaura Couplings with ppm Level of Palladium Catalyst in a High-Pressure and High-Temperature Water System

A microflow process was developed for Suzuki-Miyaura Couplings (SMCs) in high-pressure and high-temperature (HPHT) water with a small amount of ethanol. Using this approach, an efficient SMC between 4-methylphenylboronic acid and iodobenzene as a model reaction was demonstrated in water medium, in the presence of ppm order PdCl2/NaOH as a simple catalyst/base without any additional ligands, affording the desired products in good yields within <25 s of residence time. The strategy developed for SMCs also demonstrated an aspect of separation by quantitative tracing of 0.1 ppm contaminated Pd with the product, which might be attributed to the low catalyst amount along with the reaction conditions, as well as the immediate membrane separation applied in the sequence

Recent Progress in Homogeneous Catalytic Dehydrogenation of Formic Acid

Recently, there has been a strong demand for technologies that use hydrogen as an energy carrier, instead of fossil fuels. Hence, new and effective hydrogen storage technologies are attracting increasing attention. Formic acid (FA) is considered an effective liquid chemical for hydrogen storage because it is easier to handle than solid or gaseous materials. This review presents recent advances in research into the development of homogeneous catalysts, primarily focusing on hydrogen generation by FA dehydrogenation. Notably, this review will aid in the development of useful catalysts, thereby accelerating the transition to a hydrogen-based society

Functional Implications of the IL-6 Signaling Pathway in Keloid Pathogenesis

The molecular mechanism(s) behind keloid pathogenesis remains unclear. Previously by global gene expression analysis of keloid fibroblasts (KFs), we implicated the IL-6 signaling pathway in keloid pathogenesis. Here, we determine a functional role of IL-6 signaling in keloid scars. Primary cultures of KFs and surrounding nonlesional fibroblasts (NFs) were subjected to induction or inhibition of IL-6 or its specific receptor IL-6 receptor alpha (IL-6Rα) and detection of their effects on extracellular matrix gene expression. The levels of gp130 and several downstream targets in IL-6 signaling were also examined. IL-6 secretion was significantly higher in KFs than NFs. Addition of IL-6 peptide to NFs culture or inhibition of IL-6 or its receptor IL-6Rα by their corresponding antibodies in KFs culture revealed a dose-dependent increase or decrease in collagen type I alpha 2 and fibronectin 1 mRNAs, respectively. Induction of IL-6 by IL-1β peptide and stimulation by IL-6 peptide in NFs, or inhibition of IL-6 or IL-6Rα in KFs cultures demonstrated a dose-dependent increase or decease in procollagen I synthesis, respectively. The mRNA and protein expressions of gp130 and several downstream targets in IL-6 signaling (JAK1, STAT3, RAF1, and ELK1) were upregulated in KFs versus NFs. Our results indicate that IL-6 signaling may play an integral role in keloid pathogenesis and provide clues for development of IL-6 receptor blocking strategies for therapy or prophylaxis of keloid scars