Silica Gel–Supported P-, Ge-, and Sb-Porphyrins for Visible Light Inactivation of Bacteria

This chapter describes the photocatalysis action of (dihydroxo)tetraphenyl¬porphyrinato complexes of high valent P (V), Ge (IV), and Sb (V) (P(tpp), Ge(tpp), and Sb(tpp)). These chromophores were fixed onto silica gel (SiO2) through Coulombic forces and hydrogen bonding between axial hydroxo ligands and silanol groups to produce M(tpp)/SiO2 (M = P, Ge, and Sb) composites. M(tpp)/SiO2 were applied to the photo-inactivation of Escherichia coli and Legionella pneumophila. Moreover, M(tpp)/SiO2 was subjected to practical experiments for the photoinactivation of L. pneumophila naturally occurring in a cooling tower and a public fountain. It is noteworthy that 80 g of Sb(tpp)/SiO2 catalyst, containing 40 mg of Sb(tpp) maintained a concentration of Legionella species below 100 CFU/100 mL for 120 days in 13 m3 of water in a fountain under sunlight exposure. The photoinactivation proceeded through the liberation of M(tpp) from SiO2, adsorption of M(tpp) inside bacteria, and generation of reactive oxygen species, such as singlet oxygen, under visible light irradiation, thus resulting in bacteria apoptosis. Based on these results, we developed water-soluble porphyrins by modification of P and Sb porphyrin axial ligands to alkyloxo, alkylethylenedioxy, and alkylpyridinium groups. These water-soluble porphyrins were applied to the photodynamic inactivation of E. coli and Saccharomyces cerevisiae

Photodynamic Inactivation of <em>Escherichia coli</em> with Cationic Porphyrin Sensitizers

The activity of singlet-oxygen sensitizers for photodynamic inactivation (PDI) of microorganisms and photodynamic therapy of tumor cells has been evaluated using Escherichia coli, Saccharomyces cerevisiae, and human cancer cell lines. In this chapter, drug resistance of E. coli was examined based on the PDI activity of a variety of RPy-P-porphyrin sensitizers with different number of ionic valence and different hydrophobic characters. The PDI activities toward E. coli were evaluated using the minimum effective concentrations ([P]) of the porphyrin sensitizers. It was found that the [P] value for E. coli was larger than that for S. cerevisiae. E. coli has drug-resistance toward hydrophobic and mono-cationic porphyrins. However, E. coli has weak drug-resistance toward the porphyrins with both polycationic character and hydrophobicity. Since the outer membrane mainly consists of lipopolysaccharides and phospholipids that are negatively charged, cationic porphyrins are able to adsorb to the outer leaflet. Then the cationic porphyrins with hydrophobic character can interact with not only the outer leaflet but also inner leaflet of the outer membrane and the plasma membrane. Thus, porphyrins may be incorporated inside E. coli cells via the self-promoted uptake pathway. Moreover, polycationic porphyrins can interact with DNA and proteins by strong binding affinities

Glycerol as a Superior Electron Source in Sacrificial H₂ Production over TiO₂ Photocatalyst

Biodiesel fuel (BDF) has gained much attention as a new sustainable energy alternative to petroleum-based fuels. BDF is produced by transesterification of vegetable oil or animal fats with methanol along with the co-production of glycerol. Indeed, transesterification of vegetable oil (136.5 g) with methanol (23.8 g) was performed under heating at 61°C for 2 h in the presence of NaOH (0.485 g) to produce methyl alkanoate (BDF) and glycerol in 83.7 and 73.3% yields, respectively. Although BDF was easily isolated by phase separation from the reaction mixture, glycerol and unreacted methanol remained as waste. In order to construct a clean BDF synthesis, the aqueous solution of glycerol and methanol was subjected to sacrificial H2 production over a Pt-loaded TiO2 catalyst under UV irradiation by high-pressure mercury lamp. H2 was produced in high yield. The combustion energy (ΔH) of the evolved H2 reached 100.7% of the total ΔH of glycerol and methanol. Thus, sacrificial agents such as glycerol and methanol with all of the carbon attached to oxygen atoms can continue to serve as an electron source until their sacrificial ability was exhausted. Sacrificial H2 production will provide a promising approach in the utilization of by-products derived from BDF synthesis

Symmetrically dimethylated histone H3R2 promotes global transcription during minor zygotic genome activation in mouse pronuclei

受精卵の発生に重要な因子を発見 --ヒストンのアルギニンジメチル化が重要--. 京都大学プレスリリース. 2021-05-13.Paternal genome reprogramming, such as protamine–histone exchange and global DNA demethylation, is crucial for the development of fertilised embryos. Previously, our study showed that one of histone arginine methylation, asymmetrically dimethylated histone H3R17 (H3R17me2a), is necessary for epigenetic reprogramming in the mouse paternal genome. However, roles of histone arginine methylation in reprogramming after fertilisation are still poorly understood. Here, we report that H3R2me2s promotes global transcription at the 1-cell stage, referred to as minor zygotic genome activation (ZGA). The inhibition of H3R2me2s by expressing a histone H3.3 mutant H3.3R2A prevented embryonic development from the 2-cell to 4-cell stages and significantly reduced global RNA synthesis and RNA polymerase II (Pol II) activity. Consistent with this result, the expression levels of MuERV-L as minor ZGA transcripts were decreased by forced expression of H3.3R2A. Furthermore, treatment with an inhibitor and co-injection of siRNA to PRMT5 and PRMT7 also resulted in the attenuation of transcriptional activities with reduction of H3R2me2s in the pronuclei of zygotes. Interestingly, impairment of H3K4 methylation by expression of H3.3K4M resulted in a decrease of H3R2me2s in male pronuclei. Our findings suggest that H3R2me2s together with H3K4 methylation is involved in global transcription during minor ZGA in mice

Multi-Region and Multi-Component Thermal Fluid Analysis of Hydrothermal Oxidative Decomposition Reactor

To elucidate the corrosion mechanism of a hydrothermal oxidation decomposition reactor for the treatment of polychlorinated biphenyls (PCBs), a coupled thermal fluid analysis of the heat transfer between two mixtures of fluids with different physical properties and the reactor body was executed using OpenFOAM. Based on the analysis results, we propose a method to evaluate the corrosion risk at the solid-liquid interface by focusing on three factors: (1) the corrosion temperature of reactor vessel, (2) the amount of fluid deposition that causes corrosion, and (3) the wall shear stress on the solid-liquid interface. Variation of corrosion risk with operating conditions of the reactor is discussed

Water-Solubilization of P(V) and Sb(V) Porphyrins and Their Photobiological Application

Porphyrins have been widely utilized as biochemical and biological functional chromophores which can operate under visible-light irradiation. Water-soluble porphyrins have been used as the drug for photodynamic therapy (PDT) and photodynamic inactivation (PDI). Although usual water-solubilization of porphyrins has been achieved by an introduction of an ionic group such as ammonium, pyridinium, sulfonate, phosphonium, or carboxyl to porphyrin ring, we proposed the preparation of water-soluble P and Sb porphyrins by modification of axial ligands. Alkyl (type A), ethylenedioxy (type E), pyridinium (type P), and glucosyl groups (type G) were introduced to axial ligands of Sb and P porphyrins to achieve water-solubilization of Sb porphyrin and P porphyrins. Here, we review their water-soluble P and Sb porphyrins from the standpoints of preparation, bioaffinity, and photosensitized inactivation

Java Birthmarks--Detecting the Software Theft--

To detect the theft of Java class files efficiently, we propose a concept of Java birthmarks, which are unique and native characteristics of every class file. For a pair of class files p and q, if q has the same birthmark as p's, q is suspected as a copy of p. Ideally, the birthmarks should satisfy the following properties: (a) preservation - the birthmarks should be preserved even if the original class file is tampered with, and (b) distinction - independent class files must be distinguished by completely different birthmarks. Taking (a) and (b) into account, we propose four types of birthmarks for Java class files. To show the effectiveness of the proposed birthmarks, we conduct three experiments. In the first experiment, we demonstrate that the proposed birthmarks are sufficiently robust against automatic program transformation (93.3876% of the birthmarks were preserved). The second experiment shows that the proposed birthmarks successfully distinguish non-copied files in a practical Java application (97.8005% of given class files were distinguished). In the third experiment, we exploit different Java compilers to confirm that the proposed Java birthmarks are core characteristics independent of compiler-specific issues

Thermal Fluid Coupled Analysis of Hydrothermal Destruction Reactor

Multi-regionally coupled analysis of thermal fluid flow and heat conduction of solid using OpenFOAM is carried out to clarify the behavior of hydrothermal oxidative destruction reactor of polychlorinated biphenyls (PCBs). Internal fluid of the reactor assumes a single-phase hot water without chemical reactions considering temperature dependence of thermophysical properties. Compressible Navier-Stokes equation with buoyancy force and energy equation with gravity term are alternately solved for the thermal fluid analysis. In order to consider conjugate heat transfer between the internal fluid and the reactor vessel, two-regionally coupled analysis of the fluid and vessel was executed by chtMultiRegionFoam solver in the OpenFOAM. To verify coupling effect, the multi-regionally coupled analyses results were compared with thermal fluid analysis of the internal fluid or heat conduction analysis of the vessel

Development of an e-Learning environment across all departments and a model class

金沢大学総合メディア基盤センターIn 2006, Kanazawa University (KU) adopted a policy that made it mandatory for all freshmen to have a laptop PC, and started a new class called Introduction to Information Technology as a compulsory first-year subject. We designed this class as a model for developing an e-Learning environment across all departments. We realized that educational systems and support environments are important for the success of e-Learning, so we added portal functions with the cooperation of the company which developed the LMS for us. In addition, we set up a wireless LAN infrastructure, and upgraded some lecture rooms for the Introduction to Information Processing courses. We started up a support room to assist teachers in developing their teaching materials, and opened a PC support room for students in the university hall, near the hub of student activity. In this paper, we will show the outline of the educational system, and report the largely positive student evaluations of the Introduction to Information Technology course and the educational system during its first two years. The number of classes that use the educational system tripled in 2007