High-density electron anions in a nanoporous single crystal: [Ca24Al28O64]4+(4e-)

We removed approximately 100% of clathrated oxygen ions from the crystallographic cages in a single crystal of 12CaO.7Al2O3, leading to the formation of high-density (approximately 2 x 10(21) cm-3) electrons highly localized in the cages. The resulting electron forms a structure that we interpret as an F+ center and migrates throughout the crystal by hopping to a neighboring cage with conductivity approximately 100 siemens per centimeter, demonstrating that the encaged electron behaves as an anion. The electron anions couple antiferromagnetically with each other, forming a diamagnetic pair or singlet bipolaron. The resulting [Ca24Al28O64]4+(4e-) may be regarded as a thermally and chemically stable single crystalline "electride."     

鹌鹑同工酶多型性的研究

采用水平板淀粉凝胶电泳法 ,对中国目前大规模饲养的 2个蛋用品系鹌鹑的脏器、肌肉中 1 0个酶基因座多型进行检测 ,结果表明 :朝鲜龙城系和德国红鸟系鹌鹑在 Adh、Es-D、Es、Pgi、6-Pgi、Mpi- 6个基因座位均发现多态 ,在Mdh- 、Mdh- 、Mpi- 、α-Gpd 4个基因座位均为单态。引用国外研究结果 ,对国内外 2 1个鹌鹑群体进行聚类分析 ,结果表明 :野生鹌鹑群紧密聚为一类 ,家养鹌鹑群聚为一类 ,商品用鹌鹑和实验用鹌鹑无明显分化 ,而大体重鹌鹑与一般体重鹌鹑分化较大 ,可能是由于进行体重选择的群体偶然携带了不同于原种群的特定基因     

Cytokinin oxidase regulates rice grain production

Most agriculturally important traits are regulated by genes known as quantitative trait loci (QTLs) derived from natural allelic variations. We here show that a QTL that increases grain productivity in rice, Gn1a, is a gene for cytokinin oxidase/dehydrogenase (OsCKX2), an enzyme that degrades the phytohormone cytokinin. Reduced expression of OsCKX2 causes cytokinin accumulation in inflorescence meristems and increases the number of reproductive organs, resulting in enhanced grain yield. QTL pyramiding to combine loci for grain number and plant height in the same genetic background generated lines exhibiting both beneficial traits. These results provide a strategy for tailormade crop improvement.     

Co-transmission of <Emphasis Type="Italic">Tomato yellow leaf curl virus</Emphasis> (TYLCV)-Mld and TYLCV-IL by the whitefly <Emphasis Type="Italic">Bemisia tabaci</Emphasis>

The ability of the whitefly Bemisia tabaci to transmit two strains of Tomato yellow leaf curl virus, the Israel and Mild strains, was studied after serial transfers of individual whiteflies that were viruliferous for both strains to tomato plants. After single whiteflies had successive acquisition feedings first on a single plant infected with one strain and then on a plant infected with the other strain, the single whiteflies later transmitted intermittently one, the other, or both strains to the test plants during serial transfers at 1-day intervals. Because both strains were found in the head, abdomen, and legs dissected from whiteflies during the retention period after the two successive acquisition feedings, both strains apparently circulate from midgut cells to salivary glands through the hemolymph.     

Antiallergic tea catechin, (-)-epigallocatechin-3-O-(3-O-methyl)-gallate,suppresses FcepsilonRI expression in human basophilic KU812 cells

We previously found that the O-methylated derivative of (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG' '3Me), has potent antiallergic activity. The high-affinity IgE receptor, FcepsilonRI, is found at high levels on basophils and mast cells and plays a key role in a series of acute and chronic human allergic reactions. To understand the mechanism of action for the antiallergic EGCG' '3Me, the effect of EGCG' '3Me on the cell surface expression of FcepsilonRI in human basophilic KU812 cells was examined. Flow cytometric analysis showed that EGCG' '3Me was able to decrease the cell surface expression of FcepsilonRI. Moreover, immunoblot analysis revealed that total cellular expression of the FcepsilonRI alpha chain decreased upon treatment with EGCG' '3Me. FcepsilonRI is a tetrameric structure comprising one alpha chain, one beta chain, and two gamma chains. The level of mRNA production of each subunit in KU812 cells was investigated. EGCG' '3Me reduced FcepsilonRI alpha and gamma mRNA levels. The cross-linkage of FcepsilonRI causes the activation of basophils, which leads to the secretion of inflammatory mediators including histamine. EGCG' '3Me treatment inhibited the FcepsilonRI cross-linking-induced histamine release. These results suggested that EGCG' '3Me can negatively regulate basophil activation through the suppression of FcepsilonRI expression.     

Genetic factors determining varietal differences in characters affecting yield between two rice (Oryza sativa L.) varieties,Koshihikari and IR64

The yield of Koshihikari, a Japanese premium rice variety, is relatively lower than that of modern high yielding varieties. IR64 carries several well-known genes such as GS3, an important gene for grain size, sd-1, a semi-dwarf gene, and NARROW LEAF1 (NAL1), a gene for small, narrow flag leaves. In this study, we used two sets of chromosome segment substitution lines (CSSLs), from Koshihikari and IR64, and attempted to evaluate the genetic factors that cause differences between parents by analyzing the function of chromosome regions affecting a trait (CRATs). For 28 traits, we identified 312 CRATs in the Koshihikari background and 275 in the IR64 background. In these, donor alleles had positive effects in 84 and 103 CRATs, respectively. Among these, the CRAT related to GS3 and those for grain number expanded the potential sink size in Koshihikari, although this did not affect final yield. The combination of CRATs that enhances source ability may increase grain yield. Although the sd-1 gene might improve resistance to lodging, the yield of CSSLs with sd-1 decreased by 28.7 %. These results suggest that the smaller biomass conferred by sd-1 might reduce canopy photosynthesis. In the Koshihikari background, the CRAT related to NAL1 and those located on chr. 6 increased SPAD value but had the opposite effect on leaf size. Two CRATs that were detected on chr. 6 and 7 increased leaf area without any effect on the SPAD value. The combination of these CRATs for area and SPAD value might improve source ability.     

Aggregates and gel network structure of globin hydrolysates

A gel with excellent functional properties was prepared successfully using the hydrolysates of globin. In the present study, the structures of intermediate aggregates and gel network were observed directly with an electronic microscope. It was shown clearly that the intermediate aggregates were in a thin rod shape with a length of 130--140 nm, which was in good accordance with the results of the light scattering obtained in a previous study. The diameter of intermediate aggregates was 4--5 nm. Each unit of the intermediate aggregate was composed of beta-chain and peptide beta-1 in a ratio of 1:1. Its molecular weight was 26922 Da, and it had a diameter of 4.1 nm. The thin rod-shaped aggregates were formed with units through the hydrophobic interaction. The length of intermediate aggregate was >30--33 times the diameter. Furthermore, the cross-linked structure formed by peptide alpha-1 and the thin rod-shaped aggregates was also confirmed by the photography of the electronic microscope. These results supported the model proposed in previous papers as proper to depict exactly the formation and structure of the gel network of globin hydrolysates.     

Insecticide screening with isolated nerve preparations for structure-activity relationships

The sciatic nerve-sartorius muscle preparation from the frog, the nerve-muscle preparation from the crayfish, and the abdominal nerve cord preparation from the crayfish have been compared for their sensitivity to various insecticides. The crayfish nerve cord was the most sensitive to insecticides and had a broad spectrum of sensitivity. A method was developed with this preparation to compare a large number of synthetic pyrethroids for their potencies to stimulate and block the nerve which is the primary target site. Both stimulating and blocking actions on the nerve can be assessed with this preparation. Certain pyrethroids are active insecticidally despite their weak nerve action, whereas some other pyrethroids are relatively moderate in killing insects despite their potent nerve action. Thus the new method can be effectively used to establish the true structure-activity relationship of synthetic pyrethroids or any other insecticides acting directly on the nerve.