Potentiometric Responses of Polymeric Liquid Membranes Based on Hydrophobic Chelating Agents to Metal lons

液膜イオンセンサーの感応物質として用いる各種キレート試薬の疎水性が、金属イオンに対する電位応答に及ぼす効果について調べた。キレート試薬として、オキシン、ジチゾン、ビリジルアゾナフトール及びそれらの長鎖アルキル誘導体、ならびに一連のN-アルキルカルボニル-N-フェニルヒドロキシルアミン類を用いた。疎水性の高いキレート試薬を含む膜でZn2+,Ni2+などに対し大きな電位応答が得られた。一方、疎水性が低い試薬では、有意な電位応答は得られなかった。電位応答挙動、界面張力測定などの結果から、膜電位発生モデルを提案した。キレート試薬の高い疎水性は、試薬陰イオンが膜/溶液界面にとどまることを可能とする。試薬陰イオンによる金属イオンの選択的取り込みによって界面での電荷分離が達成され、結果として電位応答が生起する

Symbiotic incompatibility between soybean and Bradyrhizobium arises from one amino acid determinant in soybean Rj2 protein.

Cultivated soybean (Glycine max) carrying the Rj2 allele restricts nodulation with specific Bradyrhizobium strains via host immunity, mediated by rhizobial type III secretory protein NopP and the host resistance protein Rj2. Here we found that the single isoleucine residue I490 in Rj2 is required for induction of symbiotic incompatibility. Furthermore, we investigated the geographical distribution of the Rj2-genotype soybean in a large set of germplasm by single nucleotide polymorphism (SNP) genotyping using a SNP marker for I490. By allelic comparison of 79 accessions in the Japanese soybean mini-core collection, we suggest substitution of a single amino acid residue (R490 to I490) in Rj2 induces symbiotic incompatibility with Bradyrhizobium diazoefficiens USDA 122. The importance of I490 was verified by complementation of rj2-soybean by the dominant allele encoding the Rj2 protein containing I490 residue. The Rj2 allele was also found in Glycine soja, the wild progenitor of G. max, and their single amino acid polymorphisms were associated with the Rj2-nodulation phenotype. By SNP genotyping against 1583 soybean accessions, we detected the Rj2-genotype in 5.4% of G. max and 7.7% of G. soja accessions. Distribution of the Rj2-genotype soybean plants was relatively concentrated in the temperate Asian region. These results provide important information about the mechanism of host genotype-specific symbiotic incompatibility mediated by host immunity and suggest that the Rj2 gene has been maintained by environmental conditions during the process of soybean domestication

理科教育に科学古典を利用する一つの新らしい試み

When teaching science, teachers often present the subject matter in a sort of authoritative way according to the textbook without being able to give much stimulus to students. Students have to follow the book and passively learn what is written there. It is partly in relation to this point that student-experiments and the use of audio-visual aids are of great importance. However, these methods are not always enough to produce satisfactory results. This difficulty, the present authors presume, may be solved to some extent by making proper use of classics in science. At the time when the classical treatises were written, their authors, as scientists, were facing new problems or trying to see familiar problems from an entirely new point of view. In other words, they were still groping their way towards a grasp of unknown scientific knowledge or laws which seem quite evident nowadays. This freshness of thought and attitude revealed in their writings is very valuable and may be effectively utilized in science teaching as a source of incentive and challenge to the students\u27 attitude toward the subject matter. The present authors carefully studied Galileo\u27s Dialogue on the Great World Systems and tried to use the material to introduce the concept of "inertia" to two second-year classes of a girls\u27 junior high school. Nine questions were prepared, derived from the original discussions of the Dialogue, and the students were asked to write their answers to these questions on a sheet of paper in forty minutes. When the time was over, all of the students were very much interested in the subject and began actively to raise questions to the teacher or to discuss the matter among themselves. Thus, the result seems to have been very satisfactory. Although this is only a first trial, the present authors should like to report this result, as they think that the method described here may have some significance to the further development of science teaching

Annual report of Perinatology Committee, Japan Society of Obstetrics and Gynecology, 2013: Development of Perinatal Emergency Care Systems and Suggestions

Placetal abruption is a disease occurring irrespective of the time and location and requiring maternal-fetal emergency care, so early delivery is indispensable, and the time from the occurrence of placental abruption to delivery should be shortened as much as possible