Shape-Controlled Synthesis of ZrO₂, Al₂O₃, and SiO₂ Nanotubes Using Carbon Nanofibers as Templates

Shape-Controlled Synthesis of ZrO2, Al2O3, and SiO2 Nanotubes Using Carbon Nanofibers as Template

Control of the Optical Properties of Quantum Dots by Surface Coating with Calix[<i>n</i>]arene Carboxylic Acids

A new method for the control of the optical properties of quantum dots (QDs) has been developed using calix[n]arene carboxylic acids (1−3) as surface coating agents for QDs. The calixarene coating of CdSe/ZnS QDs was easily performed in tetrahydrofuran at room temperature. Deprotonation of the carboxyl groups of the calixarene derivatives surrounding the QDs resulted in highly fluorescent water-soluble QDs. The emission peak of the calixarene-coated QDs shifted to longer wavelengths depending on the oligomer size of the calix[n]arene derivative used for the surface coating. Although the red shift of the emission peak decreases with the increase in the particle size of QDs, this surface coating method is useful for the preparation of multi-colored water-soluble QDs from a single-colored hydrophobic QD

Degradation of hydrogen peroxide in cell suspension of <i>E. oxidotolerans</i> T-2-2^T and that in 0.1% Tween 60-treated cell suspension.

<p>The untreated cells and 0.1% Tween 60-treated cells are indicated by open circles and filled circles, respectively. The cells were obtained after 36 h of cultivation. The amount of the cells was adjusted as OD₆₅₀ = 0.005 in the final reaction mixture. The reaction was performed at 25°C.</p

Effect of pH on activities of extracellular and intracellular catalases of <i>E. oxidotolerans</i> T-2-2^T.

<p>Extracellular and intracellular catalases are indicated by filled and open circles, respectively. The buffers (50 mM) used were as follows: pHs 3.0–6.0, citrate-NaOH; pHs 4.0–5.0, acetate-NaOH; pHs 6.0–8.0, sodium phosphate; pHs 8.0–9.0, Tris-HCl; pHs 9.0–10.0, borate-NaOH. The activities are relative to that at pH 6.5, which is 100%.</p

An ultrathin section showing immunolocalization of catalase in <i>E. oxidotolerans</i> T-2-2^T after 5, 14 and 24 h of culture.

<p>The particles show the localization of catalase. Cells from 5, 14 and 24-exponential, early stationary and mid-stationary growth phases, are shown in (a), (b) and (c), respectively. Bar, 1 µm.</p

Effects of temperature on activities and stabilities of extracellular and intracellular catalases of <i>E. oxidotolerans</i> T-2-2^T.

<p>(A) Effect of temperature on catalase activity. Extracellular and intracellular catalases are indicated by filled and open circles, respectively. <i>M</i>. <i>luteus</i> catalase, indicated by closed triangles, was used as a counterpart mesophilic enzyme. Catalase activity was assayed, as described in Materials and Methods, at the temperature indicated. (B) Temperature stability of catalase. Symbols are indicated as in (A). The enzyme was incubated for 15 min at the indicated temperatures prior to activity measurement. Catalase activity was assayed at 25°C as described in Materials and Methods.</p

Inner circumference localization ratio of catalase in strain T-2-2^T cells on the basis of particles in ultrathin sections exhibiting catalase immunolocalization.

<p>Cells from 5 (n = 19), 14 (n = 33) and 24 (n = 47) h cultures are indicated by open, blue filled and red filled circles, respectively. Particles locating within 50 nm from the surface of the cell are considered as surface- localized particles. Black bars indicate the average inner circumference localization ratio in each growth phase.</p

Degradation of hydrogen peroxide in cell suspension of <i>E. oxidotolerans</i> T-2-2^T obtained from 5, 14 and 24 h cultures.

<p>Culture periods of 5, 14 and 24</p