Katsuda Y.,Dainihon Jochugiku Co.
Topics in Current Chemistry | Year: 2012
After the chemical structure of "natural pyrethrins," the insecticidal ingredient of pyrethrum flowers, was elucidated, useful synthetic pyrethroids provided with various characteristics have been developed by organic chemists throughout the world, leading to the advancement of pyrethroid chemistry. Even in pyrethroids with high selective toxicity, a chemical design placing too much importance on efficacy improvements may invite loss of the safety margin. It is strongly hoped that the development of household pyrethroids and their preparations for use in living environments around humans and pets will be achieved in the future by retaining the characteristics of natural pyrethrins. © 2011 Springer-Verlag Berlin Heidelberg. Source
Izumi H.,Kansai University |
Suzuki M.,Kansai University |
Aoyagi S.,Kansai University |
Kanzaki T.,Dainihon Jochugiku Co.
Sensors and Actuators, A: Physical | Year: 2011
Aiming at the use in low-invasive medical treatments, this paper proposes a realistic imitation of mosquito's proboscis. A silicon needle is electrochemically etched, making the three-dimensionally sharp tip with finely smooth surface. The jagged shank shape is machined by a deep reactive ion etching (DRIE). The combined needles comprising a central straight needle and two outer jagged needles are fabricated, imitating a labrum and two maxillas of the mosquito, respectively. The cooperative motion of the three needles imitating the mosquito's motion is realized by applying PZT actuators independently to all the needles. The effectiveness of inserting these needles cooperatively was experimentally confirmed. Considering practical medical application, a biodegradable polymer needle with three-dimensionally sharp tip is also developed. The fabrication process based on micromolding is as follows: a nickel negative cavity is made by electroplating on a silicon sharp needle, to which melted polymer is injected, and it is finally released using a lost molding technique. The effectiveness of sharp tip for easy insertion was experimentally proven. © 2010 Elsevier B.V. All rights reserved. Source
Ujihara K.,Sumitomo Chemical |
Mori T.,Sumitomo Chemical |
Matsuo N.,Dainihon Jochugiku Co.
Topics in Current Chemistry | Year: 2012
Development of pyrethroids for household use and recent advances in the syntheses of (1R)-trans-chrysanthemic acid, the acid moiety of most of the household pyrethroids, are reviewed. As another important acid moiety, we discovered norchrysanthemic acid to have a significant vapor action at room temperature when esterified with fluorobenzyl alcohols. In particular, 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl (1R)-trans-norchrysanthemate (metofluthrin) exhibits the highest potency in mosquito coil formulations as well as the vapor action at room temperature against various mosquitoes. Structure-activity relationships of norchrysanthemic acid esters and synthetic studies of norchrysanthemic acid are discussed. © 2011 Springer-Verlag Berlin Heidelberg. Source
Ueda H.,Kinki University |
Kikuta Y.,Dainihon Jochugiku Co. |
Matsuda K.,Kinki University
Plant Signaling and Behavior | Year: 2012
Plants emit volatile organic compounds (VOCs) as a means to warn other plants of impending danger. Nearby plants exposed to the induced VOCs prepare their own defense weapons in response. Accumulated data supports this assertion, yet much of the evidence has been obtained in laboratories under artificial conditions where, for example, a single VOC might be applied at a concentration that plants do not actually experience in nature. Experiments conducted outdoors suggest that communication occurs only within a limited distance from the damaged plants. Thus, the question remains as to whether VOCs work as a single component or a specific blend, and at which concentrations VOCs elicit insect and pathogen defenses in undamaged plants. We discuss these issues based on available literature and our recent work, and propose future directions in this field. © 2012 Landes Bioscience. Source
Dainihon Jochugiku Co. and Kinki University | Date: 2011-08-05
The present invention relates to an enzyme determining amino acid sequences of an enzyme involved in pyrethrin biosynthesis and a base sequence of the gene thereof; constructing vectors bearing the gene and transformants; and extractable from plant bodies producing pyrethrin by applying such creative techniques to plant bodies with faster growth aiming to provide a method to efficiently produce pyrethrin; and the enzyme is a gene encoding a protein of the following (i) or (ii) or (iii):