Improving Measurement Range of a Swellable Polymer-Clad Plastic Fiber Optic Humidity Sensor by Dye Addition.

Humidity measurement is required in various fields. We previously developed a sensor that leverages the sudden change in the transmitted light intensity when switching from leakage mode to waveguide mode. By adjusting the low-refractive-index polymer of the cladding, we achieved measurements at 60% RH.

Synthesis and Complete Structure Determination of a Sperm-Activating and -Attracting Factor Isolated from the Ascidian Ascidia sydneiensis.

For the complete structure elucidation of an endogenous sperm-activating and -attracting factor isolated from eggs of the ascidian Ascidia sydneiensis ( Assydn-SAAF), its two possible diastereomers with respect to C-25 were synthesized. Starting from ergosterol, the characteristic steroid backbone was constructed by using an intramolecular pinacol coupling reaction and stereoselective reduction of a hydroxy ketone as key steps, and the side chain was introduced by Julia-Kocienski olefination. Comparison of the NMR data of the two diastereomers with those of the natural product led to the elucidation of the absolute configuration as 25 S; thus the complete structure was determined and the first synthesis of Assydn-SAAF was achieved.

Clinical Application of the DiversiLab Microbial Typing System Using Repetitive Sequence-Based PCR for Characterization of Helicobacter pylori in Japan.

We evaluated the DiversiLab (DL) system with universal primers, a semiautomated repetitive extragenic palindromic sequence-based polymerase chain reaction (PCR) (rep-PCR) system, for the characterization of Helicobacter pylori in Japan. All 135 isolates from Japanese patients with gastric cancer (GC, n = 55) or non-GC (n = 80) were used and subjected to the drug susceptibility examinations (amoxicillin, AMPC; metronidazole, MNZ; and clarithromycin, CAM) by E-test. There were 28 MNZ-resistant (20.

Species-specificity of sperm motility activation and chemotaxis: a study on ascidian species.

Egg-derived sperm-activating factors and attractants activate sperm motility and attract the sperm, respectively. These phenomena constitute the first communication signaling between males and females in the process of fertilization in many animals and plants, and in many cases, these are species-specific events. Thus, sperm motility activation and chemotaxis may act as a safety process for the authentication between conspecific egg and sperm, and help to prevent crossbreeding.

A novel sperm-activating and attracting factor from the ascidian Ascidia sydneiensis.

A novel SAAF was isolated from the title ascidian. The structure was elucidated using the entire sample of 4 nmol, suggesting that the position of the OH group confers genus-specificity to sperm chemotaxis in ascidians. This study not only provides insight into the chemical tactics in sperm chemotaxis but demonstrates that the innovative techniques allow structure determination of natural products in trace amounts.