Abscisic Acid as a Stimulator for Rice Mesocotyl Growth

WHEN abscisic acid (ABA) is applied to a growing plant, it usually inhibits the growth of stem, leaf sheath and other plant parts^1–3. Here I report the possibility that ABA stimulates the growth of rice mesocotyl in darkness.     

The Effect of PCIB on the Germination and Growth of Lettuce in the Presence of Thiourea

The joint action of the anti-auxin parachlorophenoxy isobutyricacid (PCIB) and thiourea on germination and growth of lettuceseed was investigated. PCIB alone did not affect germinationor hypocotyl growth of lettuce. Root growth was stimulated byPCIB. In germination PCIB showed interaction at all the thioureaconcentrations. All thiourea concentrations reversed the stimulationof root growth caused by PCIB, except the lowest thiourea concentrationwith the highest PCIB one. In hypocotyl growth the two substances showed no interaction.These results are discussed in relation to the auxin and anti-auxineffects in germination and growth.     

神经刺激仪的设计

目前电刺激器在医院麻醉和理疗科室的应用已十分普遍。本文介绍的神经刺激器是用于麻醉时神经定位和神经肌肉功能监测。微处理器产生电脉冲,经过D／A（数／模）转化输出强度可调的脉冲电流,针对不同病人采用不同刺激频率,同时显示刺激电流的大小。刺激器有两种功能：自动循环进行刺激和手动选择刺激频率挡。     

真菌在兰科植物种子萌发生长中的作用及相互关系

本文从真菌在兰科种子萌发中的应用、真菌侵染的过程、种子和根系消化真菌的途径及共生真菌的分布等方面,综述了真菌与兰科植物种子萌发及菌根关系的研究进展,讨论了该研究的有关问题及真菌在兰科种子萌发中应用的前景。     

B淋巴细胞刺激因子研究进展

B淋巴细胞刺激因子（BlyS)是1999年发现的肿瘤坏死因子家族的一个新成员。它不仅可诱导肿瘤细胞凋亡,更重要的是可调节B淋巴细胞的活化,增殖及成熟,并且参与了T淋巴细胞的活化,在自身免疫性疾病及免疫缺陷病中起着重要的作用,因此,BlyS有望成为治疗这些疾病的有效靶目标。     

The GABAA Receptor Complex as a Target for Fluoxetine Action

The clinically important antidepressant fluoxetine is established as a selective serotonin reuptake inhibitor. This study demonstrates that fluoxetine also interacts with the GABA_A receptor complex. At concentrations above 10 M fluoxetine inhibited the binding of both [³H]GABA (IC₅₀ = 2 mM) and [³H]flunitrazepam (IC₅₀ = 132 M ) to the GABA_A receptor complex in brain cortical membranes. Low fluoxetine concentrations (1 nM) enhanced GABA-stimulated Cl^– uptake by a rat cerebral cortical vesicular preparation. At higher concentrations (100 M and 1 mM), however, fluoxetine inhibited GABA-stimulated Cl^– uptake, an effect related to a reduction in E_max. These observations might assist in an explanation of the basis of the antidepressant action of fluoxetine.     

Phytochrome Action during Prechilling Induced Germination of Betula papyrifera Marsh

Seeds of paper birch (Betula papyrifera Marsh.) were induced to germinate by prechilling at 3 C or by red light. The light requirement was mediated by phytochrome and the action of phytochrome during prechilling was investigated. Red irradiation (R) prior to prechilling markedly enhanced the effectiveness of the prechilling treatment in inducing subsequent germination at 18 C. Reversal of this enhancement by far-red irradiation (FR) was more effective when FR was supplied after a 1-week prechill treatment than after a 2-week treatment. The R enhancement effect exhibited a sharp drop as prechilling temperature was increased from 5 to 7 C. This decline is consistent with a membrane phase transition at about 7 C where Pfr action is diminished by a loss in sensitivity of its receptor sites. Although phytochrome action was observed during prechilling treatments, the seeds failed to germinate at prechilling temperatures. Therefore, it was concluded that while potentiation of germination by Pfr occurred during prechilling, some other reaction(s) leading to radicle protrusion requires higher temperatures. In one seed source loss of germination potential was observed with protracted storage at 3 C. This was prevented by R supplied during the prechilling treatment. Taken collectively the data suggest that action of phytochrome during prechilling is accentuated in these seeds by two factors: (a) an increase in the sensitivity (or number) of Pfr receptor sites; and (b) preservation of Pfr by deferment of thermal reversion.     

Action Research as a Professional Development Activity

Reflective teachers are always searching for ways to improve their teaching. When this reflection becomes intentional and systematic, they are engaging in teacher research. This type of research, sometimes called action research, can help bridge the gap between theory and practice by addressing topics that are relevant to practicing teachers. This article synthesizes literature within music education and general education to address (a) the conceptual underpinnings of action research, (b) characteristics of action research and teacher research, (c) action research critiques, and (d) implications for teacher research as a form of professional development.     

Two Sites of Hormonal Action during Germination of Chenopodium album Seeds

During the overall germination process in the light-requiring seeds of Chenopodium album L. two sites of hormonal action can be distinguished. The start of visible growth is induced in darkness by the gibberellins 4 and 7 (GA₄₊₇) or by ethylene. Added cytokinins are inactive although 8-¹⁴C-kinetin shows rapid penetration into the seed and rapid turnover. The induction of growth by GA₄₊₇ and the uptake of 8-methylene-¹⁴C-GA₃ are enhanced at lower pH values. Prolonged incubation in darkness results in a decreased responsiveness of the seeds towards GA₄₊₇ and ethylene. A second site of hormonal action is located during the progress of growth inside the covering structures. ABA inhibits radicle growth, while GA₄₊₇, GA₃, kinetin, zeatin and ethylene reduce the inhibition.     

人B淋巴细胞刺激因子C端肽的免疫增强作用

用套式PCR从人胎脑cDNA文库中克隆了B淋巴细胞刺激因子C端肽 (C terminalpeptideofBlymphocytestimulator,C BLyS)的cDNA。在大肠杆菌BL2 1CodonPlus (DE3)RIL中以包含体形式表达了C BLyS。对包含体的复性条件进行了摸索 ,建立了C BLyS的透析复性与纯化方法。经复性和纯化的C BLyS可结合其受体B细胞成熟抗原 (Bcellmaturationantigen ,BCMA) 人IgG1Fc融合蛋白 ,刺激体外培养的小鼠脾脏细胞增殖 ,并且可明显增强小鼠对溶菌酶的免疫应答水平。     

Arsenite-BAL as an Inhibitor of Germination

Imbibition of light-sensitive lettuce seeds in mixed solutions of sodium arsenite and 2,3-dimercaptopropanol (BAL) inhibits light-induced germination more potently than does arsenite alone, particularly at higher temperatures. There is limited reversal of the enhanced inhibition at high BAL/arsenite ratios. The complex is also more inhibitory than arsenite after shorter periods of imbibition. Monothiol compounds do not give the increased inhibition, nor do combinations of BAL with other thiol group reagents. Greater penetrability, possibly into some internal compartment of the cell, is suggested as the cause of the enhancement. Induction of germination by gibberellic acid or low temperature is equally sensitive to arsenite-BAL. The extent of the inhibition of germination of 9 other species by arsenite-BAL is not clearly related to their light-sensitivity.     

干扰素基因刺激因子和自噬的相互关系

干扰素基因刺激因子（stimulator of interferon genes,STING）是病毒DNA或自身DNA激活免疫系统的关键蛋白质和重要感受器。自噬（autophagy）是降解细胞质成分、蛋白质聚集体和/或细胞器的一种生理过程。STING和自噬在细胞、组织和机体稳态中发挥着至关重要的作用。已证实,STING或自噬功能紊乱与人类多种疾病密切相关。近年来诸多研究提示,STING与自噬存在相互影响、相互作用,共同参与疾病的发生与发展过程。本文总结了最新关于STING与自噬相互调节的机制及其与人类重大疾病的关系,并深入讨论其对疾病治疗的潜在影响和科学意义。