植物镁素营养的研究进展

总结近些年来有关镁素营养研究应用。详细综述植物对镁的吸收、镁在植物体内的分配与运输、镁的生理作用、植物体内镁与一些元素间的相互作用。     

DIFFERENTIATION OF INTRACAPSULAR CELLS IN THE SPOROPHYTE OF SPHAEROCARPOS DONNELLII

Ultrastructural and histochemical changes during intracapsular cell differentiation in the premeiotic sporophyte of the liverwort Sphaerocarpos donnellii Austin were studied. From an initially undifferentiated meristematic tissue, spore mother cells and nutritive cells become differentiated. The first indications of ultrastructural differentiation into two cell types are the accumulation of lipid within spherosomes and the occurrence of plastid tubules in the presumptive spore mother cells. Once differentiated the two cell types are clearly distinguishable on the basis of cytoplasmic vacuolation, stored food reserve, and cell and nuclear size. The mature spore mother cell contains many spherosomes, small vacuoles, starch-containing plastids, and a large central nucleus. The mature nutritive cell, on the other hand, is extremely vacuolate and contains large, starch-filled plastids, a few spherosomes, and a small nucleus. A previously undescribed type of cell was observed in developing sporophyte capsules. This cell is located peripherally in the capsule and degenerates during differentiation of spore mother cells and nutritive cells.     

INTERCALARY MERISTEMATIC ACTIVITY IN THE SPOROPHYTE OF FUNARIA (MUSCI)

Marking procedures were combined with anatomical techniques to establish that in Funaria (1) the apical region does not act as an apical meristem contributing to seta growth, and (2) the subapical region contains an intercalary meristem the derivatives of which account for the elongation of the seta. In sporophytes that are 8 mm long there is a distinctive difference in the pattern of cell division in the apical and subapical regions. Large, undivided endothecial cells exist in the apical region, and a central strand of elongated cells occupies the analogous position in the subapical region. The apical region is earmarked to form the operculum and spore sac and part of the apophysis. There is an ontogenetic continuity between the seta and the lower portion of the apophysis, but the uppermost cells of the subapical region do not contribute to seta formation. Instead, these cells and those at the base of the apical region form a transitional zone between apical and subapical influences, and they account for most of the stomates that develop on the apophysis.     

柱状田头菇(白杨树菇)中蛋白质的营养评价

柱状田头菇（白杨树菇）Agrocybe cylindracea(=Agrocybe aegerita)又名柳环菌、柳松茸。属伞菌目,田头菇属。该菇味道鲜,盖肥柄脆,气味香浓,是一种食药用价值很高的伞菌,但关于该菇的营养价值的研究,国内外未见报道。本文分析了柱状田头菇子实体的氨基酸组成,采用国际上通用的评价方法(FAO,1970),对其营养进行评价。 1材料与方法 1.1供试样品 采用棉籽壳料栽培的新鲜柱状田头菇子实体,采收后75℃烘干,粉碎后作分析样品。 1.2蛋白质测定 采用凯氏定氮法测定柱状田头菇子实体蛋白质 1.3氨基酸组成分析 采用日立835-50型自动分析仪…     

放射性铈在模拟水生生态系中的行为

研究＾１４１Ｃｅ在水－底泥－水生动植物系统中的迁移和消长动态,结果表明,系统各组分中＾１４１Ｃｅ浓度与时间关系由多项指数描述,其中池水中的＾１４１Ｃｅ浓度随时间延长单调地降低,底泥中＾１４１Ｃｅ浓度随时间延长增加,水生动植物中＾１４１Ｃｅ浓度则各自经历某一最大值后逐渐降低,水生动植物对＾１４１Ｃｅ皆有一定的富集能力,其大小次序依次为：金鱼藻〉螺狮〉鱼,而鱼体中的＾１４１Ｃｅ主要集中内脏,螺壳与螺肉     

THE USE OF RADIOACTIVE IODINE IN THE TREATMENT OF GRAVES' DISEASE

Fifty patients with uncomplicated Graves'' disease were treated with radioactive iodine (I₁₃₁). Twenty-six patients who were followed for one year or longer are the basis of this report. Twenty-five are now euthyroid; only one is not completely well.The total dose of radioiodine administered varied from 0.5 to 10 millicuries. The average length of time necessary for return to a euthyroid state was from three to four months.Hypometabolism developed in three patients, and in one the signs and symptoms of myxedema developed. No other complications ensued. One patient who apparently relapsed had complete return to normal after further iodine administration.The determination of the uptake of radioactive iodine by the thyroid gland is a useful diagnostic procedure in differentiating conditions simulating hyperthyroidism.Following treatment with radioactive iodine, the thyroid gland becomes smaller, the uptake of iodine by the gland is reduced, and the level of organic iodine in the plasma becomes normal.In acute thyroiditis, in spite of a high basal metabolic rate, high content of organic iodine in the plasma and other evidences of “hyperthyroidism,” the uptake of I₁₃₁ has been very low.