The Roles of Two CNG Channels in the Regulation of Ascidian Sperm Chemotaxis

Spermatozoa sense and respond to their environmental signals to ensure fertilization success. Reception and transduction of signals are reflected rapidly in sperm flagellar waveforms and swimming behavior. In the ascidian Ciona intestinalis (type A; also called C. robusta), an egg-derived sulfated steroid called SAAF (sperm activating and attracting factor), induces both sperm motility activation and chemotaxis. Two types of CNG (cyclic nucleotide-gated) channels, Ci-tetra KCNG (tetrameric, cyclic nucleotide-gated, K⁺-selective) and Ci-HCN (hyperpolarization-activated and cyclic nucleotide-gated), are highly expressed in Ciona testis from the comprehensive gene expression analysis. To elucidate the sperm signaling pathway to regulate flagellar motility, we focus on the role of CNG channels. In this study, the immunochemical analysis revealed that both CNG channels are expressed in Ciona sperm and localized to sperm flagella. Sperm motility analysis and Ca²⁺ imaging during chemotaxis showed that CNG channel inhibition affected the changes in flagellar waveforms and Ca²⁺ efflux needed for the chemotactic turn. These results suggest that CNG channels in Ciona sperm play a vital role in regulating sperm motility and intracellular Ca²⁺ regulation during chemotaxis.     

Effective decolorizations and mineralizations of organic dyes over a silver germanium oxide photocatalyst under indoor-illumination irradiation

A silver germanium oxide, Ag₂GeO₃, was developed as a novel photocatalyst for degradation of organic dyes. The chemical composition of the sample was investigated via the SEM/EDX, ICP-AES, and TG-DTA techniques. The general activity of the material was characterized by testing the photodegradations of typical organic dyes, such as Methylene Blue (one of the heteropolyaromatic dyes), Rhodamine B (one of the xanthene dyes), Fuchsin Acid (one of the sulfonic dyes), and Orange II (one of the azoic dyes). All of these dyes were degraded more than 90% within 25 min under the visible-light irradiation of Xe lamp. Besides, with a commercial white fluorescent lamp as testing light source (light intensity, 61 μW/cm²), the efficient decolorizations and mineralizations of the organic dyes were achieved over this material: 79% (90%) of the organic carbon in the Methylene Blue (Rhodamine B) solution was photooxidatized to inorganic carbon forms, when these dyes were totally decolorized. The high performance of this material is due to the photophysical properties of the wide-visible-range absorption and response, and the sufficient oxidative potential of the top of the valence band.     

Production of Propylene from Ethanol Over ZSM-5 Zeolites

In this work, we studied the conversion of ethanol to propylene over ZSM-5 zeolites. The catalytic performance of H-ZSM-5 (Si/Al₂ = 30, 80, and 280) and ZSM-5 (Si/Al₂ = 80) modified with various metals was investigated. H-ZSM-5(Si/Al₂ = 80) afforded high propylene yield, which indicates that a moderate surface acidity favored propylene production. Zr-modified ZSM-5(80) gave the highest yield (32%) of propylene at 773 K. Furthermore, the catalytic stability of the zeolite was improved by the modification of zirconium. The surface acidity and the presence of metal ions played important roles on the production of propylene.     

Anti-Tumor Effect of Orally Administered Spinach Glycolipid Fraction on Implanted Cancer Cells, Colon-26, in Mice

We succeeded in purifying a major glycolipid fraction from a green vegetable, spinach. This fraction consists mainly of three glycolipids: monogalactosyl diacylglycerol (MGDG), digalactosyl diacylglycerol (DGDG), and sulfoquinovosyl diacylglycerol (SQDG). In a previous study, we found that the glycolipid fraction inhibited DNA polymerase activity, cancer cell growth and tumor growth with subcutaneous injection. We aimed to clarify oral administration of the glycolipid fraction, suppressing colon adenocarcinoma (colon-26) tumor growth in mice. A tumor graft study showed that oral administration of 20 mg/kg glycolipid fraction for 2 weeks induced a 56.1% decrease in the solid tumor volume (P < 0.05) without any side-effects, such as loss of body weight or major organ failure, in mice. The glycolipid fraction induced the suppression of colon-26 tumor growth with inhibition of angiogenesis and the expression of cell proliferation marker proteins such as Ki-67, proliferating cell nuclear antigen (PCNA), and Cyclin E in the tumor tissue. These results suggest that the orally administered glycolipid fraction from spinach could suppress colon tumor growth in mice by inhibiting the activities of neovascularization and cancer cellular proliferation in tumor tissue.     

Structure–Affinity Relationship Study of Bleomycins and Shble Protein by Use of a Chemical Array

Natural product libraries for SAR studies : We used a chemical array platform to study the SARs of bleomycin (BLM) derivatives and Shble protein. The on‐chip SARs suggested that several domains are important for recognition of BLMs by Shble protein. In particular, the C‐terminal tail and the propionamide moiety in pyrimidoblamic acid (PBA) were shown to be important for the binding.

     

Oxygen-Enhanced Crystallization of Solution-Derived 12CaO·7Al2O3

12CaO·7Al₂O₃ (C12A7) composed of nanosize cage structure can clathrate oxygen radicals (O⁻) and has a high potential to application of strong oxidizing catalysis. In the present report, we demonstrate a fabrication route to C12A7 fine powders by Chemical Solution Deposition method in order to enhance the catalytic reactivity. Aluminum sec-butoxide, calcium nitrate tetrahydrate, acetylacetone, 2-methoxyethanol, and nitric acid were used as raw materials. Precursor solution was dried and annealed at 800°–900°C in air or O₂ atmosphere. Crystalline C12A7 powders were obtained by annealing at 900°C in O₂ atmosphere. Scanning electron microscope and transmission electron microscope images of the obtained powders revealed C12A7 particles were sintered and formed several micrometer particles with many pores. BET specific surface area of the powders was 4.2 m²/g. Possibility for synthesizing C12A7 powder with higher specific surface area by the solution process was indicated.     

Operando X-ray Absorption Spectroscopy Study of Pt/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> During the Total Oxidation of C<Subscript>3</Subscript>H<Subscript>6</Subscript>

Operando X-ray absorption fine structure (XAFS) investigations were performed on Pt/γ-Al₂O₃ during the total oxidation of C₃H₆ in reducing and oxidizing atmospheres. Study of the Pt valance state and catalytic conversion behavior as a function of temperature revealed that both the creation of metallic Pt sites and the activation of adsorbed species on Pt are important for the functioning of the catalytic reaction at low temperature.     

Practical application of toxicogenomics for profiling toxicant-induced biological perturbations

A systems-level understanding of molecular perturbations is crucial for evaluating chemical-induced toxicity risks appropriately, and for this purpose comprehensive gene expression analysis or toxicogenomics investigation is highly advantageous. The recent accumulation of toxicity-associated gene sets (toxicogenomic biomarkers), enrichment in public or commercial large-scale microarray database and availability of open-source software resources facilitate our utilization of the toxicogenomic data. However, toxicologists, who are usually not experts in computational sciences, tend to be overwhelmed by the gigantic amount of data. In this paper we present practical applications of toxicogenomics by utilizing biomarker gene sets and a simple scoring method by which overall gene set-level expression changes can be evaluated efficiently. Results from the gene set-level analysis are not only an easy interpretation of toxicological significance compared with individual gene-level profiling, but also are thought to be suitable for cross-platform or cross-institutional toxicogenomics data analysis. Enrichment in toxicogenomics databases, refinements of biomarker gene sets and scoring algorithms and the development of user-friendly integrative software will lead to better evaluation of toxicant-elicited biological perturbations.     

Rheology and pressure filtration of aqueous SiC suspensions of nanometer-sized bimodal particles

The consolidation behavior of mixed SiC particles (30 and 800 nm diameters) at pH 7 was examined using a developed pressure filtration apparatus at a constant crosshead speed of a piston. The addition of 30 nm SiC to 800 nm SiC changed the rheological properties of colloidal suspension from Newtonian to pseudoplastic flow through Bingham flow with increasing amount of 30 nm SiC. A phase transition from a well dispersed suspension to a flocculated suspension occurred when the applied pressure exceeded a critical pressure (ΔP_tc). The ΔP_tc value decreased with increasing amount of 30 nm SiC. The packing density of bimodal SiC particles was analyzed based on the partial molar volume of each powder. The larger particles were more densely packed than the smaller particles in the mixed powder compact.     

Specific Spatial Localization of Actin and DNA in a Water/Water Microdroplet: Self‐Emergence of a Cell‐Like Structure

The effect of binary hydrophilic polymers on a pair of representative bio‐macromolecules in a living cell has been examined. The results showed that these bio‐macromolecules exhibited specific localization in cell‐sized droplets that were spontaneously formed through water/water microphase segregation under crowding conditions with coexisting polymers. In these experiments, a simple binary polymer system with poly(ethylene glycol) (PEG) and dextran (DEX) was used. Under the conditions of microphase segregation, DNA was entrapped within cell‐sized droplets rich in DEX. Similarly, F‐actin, linearly polymerized actin, was entrapped specifically within microdroplets rich in DEX, whereas G‐actin, a monomeric actin, was distributed evenly inside and outside these droplets. This study has been extended to a system with both F‐actin and DNA, and it was found that DNA molecules were localized separately from aligned F‐actin proteins to create microdomains inside microdroplets, reflecting the self‐emergence of a cellular morphology similar to a stage of cell division.