满江红鱼腥藻(Anabaena azollae)和柱孢鱼腥藻(A.cylindrica)营养细胞和异形胞色素的种类

满江红鱼腥藻和柱孢鱼腥藻营养细胞和异形胞的液氮低温吸收光谱表明两种细胞含有叶绿素a、藻蓝素和β-胡萝卜素。液氮低温荧光发射光谱表明:柱孢鱼腥藻营养细胞存在藻蓝素、别藻蓝素和两个光系统的叶绿素a,柱孢鱼腥藻异形胞存在藻蓝素和系统Ⅰ叶绿素a。荧光发射光谱的685nm荧光发射仅为微弱突起。满江红鱼腥藻异形胞亦存在藻蓝素和系统Ⅰ叶绿素a,缺少系统Ⅱ叶绿素a。推断满江红鱼腥藻和桩孢鱼腥藻营养细胞分化为异形胞时,伴随光系统Ⅱ的改组。系统Ⅱ叶绿素a消退和藻胆色素含量显著减少。     

不同波长光下生长的柱孢鱼腥藻和满江红鱼腥藻的荧光光谱特性

在日光灯下生长的满江红鱼腥藻(Anabaena azollae),其叶绿素a所吸收光的激发能在两个系统间的分配相近于柱孢鱼腥藻(A.cylindrica)。两个光系统发射荧光强度与藻蓝素发射荧光强度的比值分别较柱孢鱼腥藻高,但两个光系统荧光发射强度的比值较低。满江红鱼腥藻藻蓝素吸收光的激发能有效地传递给两个光系统,并以较大的比例分配至光系统Ⅰ。在520 nm光下的满江红鱼腥藻,其叶绿素a所吸收光的激发能,与柱孢鱼腥藻相比,以较大的比例分配给光系统Ⅱ;而在600 nm光下的藻丝,其叶绿素a所吸收光的激发能在两个光系统间的分配与柱孢鱼腥藻相近似。600 nm光提高了满江红鱼腥藻别藻蓝素所吸收光的激发能对光系统Ⅱ荧光发射的贡献。生长在600 nm光下的藻丝较生长在520 nm光下的藻丝有更高的叶绿素a所吸收光的激发能传递效率。藻丝生长在不同波长光下有着不同的叶绿素a和藻蓝素所吸收光的激发能传递和激发能在两个光系统间的分配。     

柱孢鱼腥藻(Anabaena cylindkica)营养细胞和异形胞叶绿素蛋白复合体的比较研究

比较了柱孢鱼腥藻(Anabaena cylindrica)营养细胞和异形胞类囊体膜叶绿素蛋白复合体的种类和性质。以SDS增溶营养细胞类囊体膜和不连续聚丙烯酰胺电泳分离得到4个P700叶绿素a蛋白复合体,分别为GPIa、CPIb、CPIc和CPI;和1个系统Ⅱ叶绿素蛋白复合体CPa。相对迁移率小的4个复合体含有P700,呼收光谱红区吸收峰为675nm,液氮低温荧光发射光谱有728nm荧光发射峰。CPIa和CPI的分量子分别为205 和105千道尔顿。未见诸文献的CPIb和CPIc复合体的分子量介于CPIa和CPI之间。相对迁移率较大的CPa有着吸收光谱红区672nm吸收峰,液氮低温荧光发射光谱有687nm荧光发射峰,分子量为56千道尔顿。同时化学氧化还原差示光谱不表现P700吸收降低。柱孢鱼腥藻异形胞类囊体膜经SDS增溶和电泳分离得到2个系统Ⅰ叶绿素蛋白复合体,它们的吸收光谱特性和分子量大小相近于营养细胞分离的CPIa和CPI复合体。异形胞类囊体膜缺少系统Ⅱ叶绿索蛋白复合体。     

蓝光对满江红鱼腥藻吸收光谱和荧光光谱特性的影响

生长在蓝光下的满江红鱼腥藻的β-胡萝卜素吸收与叶绿素a和藻蓝素吸收的比值较生长在日光灯光下的藻丝低,即在相同的β-胡萝卜素吸收基础上,生长在蓝光的藻丝有更大比例的叶绿素a和藻蓝素的吸收,在相同的叶绿素a含量的基础上,生长在蓝光下的藻丝,其光系统Ⅱ和光系统Ⅰ发射荧光强度与藻蓝素发射荧光强度的比值皆较生长在日光灯光下的藻丝高。藻蓝素所吸收光的激发能有效地传递给两个光系统。光系统Ⅱ可变荧光强度和固定荧光强度的比值亦较生长在日光灯光下的藻丝高。藻丝细胞在蓝光下具有高的色素所吸收光激发能传递效率和激发能利用效率,使满江红鱼腥藻更有较地利用共生体内环境的较短波长的光。     

镁离子对柱孢鱼腥藻(Anabaena cylindrica)类囊体膜吸收光谱和荧光光谱的影响

研究了不同浓度(5和10mM)的镁离子对柱孢鱼腥藻类囊体膜吸收光谱和荧光光谱的影响。5mM镁离子浓度降低柱孢鱼腥藻类囊体膜的叶绿素α在红区和蓝区的吸收峰,表现相似于镁离子对叶绿体的叶绿素α吸收峰的变平效应。在室温下,加入5mM镁离子浓度使膜的光系统Ⅱ684nm发射荧光强度降低。在液氮低温下,镁离子降低膜的光系统Ⅱ684nm和光系统Ⅰ728nm发射荧光强度的比值。可能表明镁离子促进光系统问激发能的传递。同时,镁离子增大叶绿素α所吸收光的激发能对光系统Ⅰ发射荧光的贡献,促进叶绿素α至光系统Ⅰ的激发能传递。     

满江红鱼腥藻(Anabaena azollae)的色素组成和能量的传递

用滚压法分离满江红鱼腥藻,测定其吸收光谱和荧光光谱。这些光谱表明,在满江红鱼腥藻中含有Chl a、类胡萝卜素、藻红素、藻蓝素和别藻蓝素等色素。这些色素都能传递光能。其中最有效的激发光是620 nm(藻蓝素),而类胡萝卜素的效率最低。PS Ⅰ和PS Ⅱ的荧光都可由藻胆素所吸收的光引起。藻胆素在光合作用中起着吸收和传递光能的作用。值得注意的是,在满江红鱼腥藻中还含有P_(330)物质。在室温下它能把光能传给藻胆素和Chl a,而在77°K下则不能。分析可能是由于在室温下色素的振幅远比在77°K下的大,而使光能能够传递下去,或者是由于其它更复杂的原因。P_(330)物质不溶于80％丙酮。     

在供给氮源和光暗条件下满江红鱼腥藻(Anabaena azollae)的荧光光谱特性

生长在氮培养介质的满江红鱼腥藻藻丝表现藻蓝素638nm荧光发射峰;而生长在无氮培养介质的藻丝主要表现藻蓝素642nm荧光发射峰。生长在无氮培养介质的藻丝藻胆色素所吸收的光激发荧光强度对叶绿素a 678nm所吸收的光激发荧光强度的比值较生长在有氮培养介质的藻丝为高,表明生长在无氮培养介质的藻丝有更高的激发能传递效率。生长在有氮和无氮培养介质的藻丝移置暗处40小时,藻胆色素所吸收的光激发荧光强度对678nm叶绿素a所吸收的光激发荧光强度的比值增大;随着暗处理时间增长,比值逐趋增大,表明暗处理降低叶绿素a的激发能传递。暗处理的藻丝再移置光下,藻丝的光系统Ⅰ和光系统Ⅱ叶绿素a的荧光发射强度增强;藻胆色素所吸收的光激发荧光强度对678nm叶绿素a所吸收的光激发荧光强度的比值显著地下降,表明暗处理后的藻丝在光下迅速恢复叶绿素a激发能传递的活跃状态。可能表明蓝绿藻色素间激发能传递的调节是适应变化着环境的一种有效方式。     

不同光质下生长的满江红叶绿体和共生者满江红鱼腥藻的吸收光谱和荧光光谱的研究

测定了不同光质下培养的满江红的叶绿体和满江红鱼腥藻的吸收光谱和荧光光谱。吸收光谱表明:对于前者叶绿体,红光和蓝光比白光和绿光更有利于Chl a的形成。对于后者光对其色素的影响比叶绿体更为敏感。在白光下其胆藻素含量最高,在红光下P_(330)含量最高,依次为蓝光、白光、绿光;而类胡萝卜素相对稳定。荧光发射光谱表明:红光下培养的满江红的叶绿体PS Ⅱ荧光发射最强,蓝光、白光、绿光依次减弱。这与我们在电镜下观察到叶绿体膜垛叠的结果是一致的。而在满江红鱼腥藻中,不同光质下的差异与叶绿体不同。从荧光光谱和类囊体膜垛叠的分析表明,我们从另一方面支持了Arntzen等(1977)关于系统Ⅱ颗粒主要分布在基粒膜上的观点。     

满江红鱼腥藻的相对耐热性

利用加温处理引起藻丝叶绿素a可变荧光强度的变化,以测定满江红鱼腥藻(Anabaena azollae imbricata)的相对耐热性。藻丝在25℃下可变荧光和固定荧光的比值为0.35±0.05;在37℃下(5分钟),相应的比值为0.27;在45℃下比值降至0.11。在50℃下,叶绿素a可变荧光几乎完全消失。较高温度可能引起光合电子传递链成分的构象和功能的变化,减少了光能的利用。结果表明满江红鱼腥藻可以忍受37℃的温度。     

鱼腥藻7120响应NaCl胁迫的光合特性

NaCl胁迫处理丝状蓝藻鱼腥藻7120后光合特性的变化表明;鱼腥藻7120的净光合放氧速率和呼吸速率随NaCl浓度的程式高而降低,且浓度低于0.4mol/LNaCl时的降幅比高于0.4mol/LNaCl时的降幅小,加入0.4%(W?V)的蔗糖后可提高盐胁迫后的鱼腥藻7120的光合放氧速率,吸收光谱测定结果表明盐胁迫没有改变鱼腥藻7120的光合色素组成,但导致藻胆蛋白的总含量降低,类胡萝卜素含量增加。低温荧光发射光谱测定表明盐胁迫后改变了光能在两个光系统之间的分配。由藻胆蛋白吸收的光能向光Ⅱ传递受阻。荧光动力学分析表明光系统Ⅱ的光化学效率随盐浓度的增加而降低。表现出与光合放氧速率的一致性。     

现代化分支杆菌菌库和基因库的建立与管理

医院分支杆菌菌库和基因库的建立 ,应用了计算机管理 ,不仅使各类菌及其相关资料得到系统管理 ,也为进一步研究和临床制定治疗计划提供了可靠信息 ,是医院现代化建设不可缺少的一环。     

紫杉醇及其衍生物的研究概况与发展趋势

本文分别从生物资源,药理学,化学合成和组织培养方面对红豆杉植物中紫杉醇及其衍生物的研究工作进行了综述,从中可以了解紫杉醇及其衍生物的研究概况与发展趋势。     

MORPHOLOGY AND ANATOMY OF NEW SPECIES OF SCHIZAEA AND ACTINOSTACHYS

The gametophyte, old embryo, and sporophyte of Schizaea pseudodichotoma sp. nov., sporophyte and female parental gametophyte of S. diversispora hybr. nov. (S. pseudodicholoma X probably S. dichotoma), sporophyte of S. rhacoindusiata sp. nov., and gametophyte, old embryo, and sporophyte of Actinostachys macrofunda sp. nov. are described. The taxonomy of Schizaea is discussed and the system of Diels is strongly supported. The two sectional names used by Diels, Euschizaea Hook, and Lophidium Rich, are replaced by Pectinatae Prantl and Schizaea respectively. The prime morphological significance of Schizaea pseudodicholoma lies in its leafless embryo and its simple leaf differing from other species in its section, and that of Actinostachys macrofunda lies in its reduction to nearly complete heterotrophic existence and its frequent multiple annulus. Fungal hyphae have been traced from Schizaea and Actinostachys through the substratum and into root nodules of Casuarina and into roots of two other angiosperms.     

DISTRIBUTION OF AMINO ACIDS AND OF EXO- AND ENDOPEPTIDASES ALONG VERTEBRATE AND INVERTEBRATE NERVES

Abstract— The proximo-distal gradients for representative peptidases, peptidylpeptide hydrolases, and amino acids were measured in segments of peripheral nerve from invertebrates and vertebrates and in the lobster brain and ventral cord.
Crustacean nerve was characterized by a large pool of free amino acids totaling 100–200 μmoles/g wet wt. In lobster nerve, the principal free amino acid was aspartic acid which comprised 55 per cent of the free pool, whereas in the rat sciatic nerve it comprised only 5 per cent. The principal free amino acid in rat sciatic nerve was taurine (32 per cent of the pool) and in lobster brain glycine comprised 30 per cent of the pool. No consistent patterns emerged for the gradients along the nerves for amino acids and hydrolytic enzymes. In the leg nerve of the lobster, concentrations of aspartic acid and arginine were higher in the proximal region, and concentrations of proline and alanine were higher in the distal region. Concentrations of most amino acids were higher in the proximal regions of crab nerve, of lobster brain and ventral cord, and of rat sciatic nerve.
Rat sciatic nerve exhibited a pronounced proximo-distal increase in activity of aminopeptidase (Leu-Gly-Gly). In lobster leg nerve, activity of neutral proteinase was higher in the proximal segment, whereas activity of acid proteinase was higher in the distal segment. The best examples of proximo-distal gradients were found in lobster brain and ventral cord; activities of endopeptidases, arylamidases (Leu- and Arg-βNA), and aminopeptidase were higher in the supra-esophageal ganglia or cephalothorax segments than in the distal regions.     

ANATOMY AND DEVELOPMENT OF THE FLOWER AND FRUIT OF PERESKIA PITITACHE

Boke, Norman H. (U. Oklahoma, Norman.) Anatomy and development of the flower and fruit of Pereskia pititache. Amer. Jour. Bot. 50 (8): 843–858. Illus. 1963.—Flowers of P. pititache are about 6 cm in diameter and perigynous. The receptacle bears numerous broad bracts; the inner perianth segments are orange and deeply cleft; the numerous stamens develop centrifugally. The fundamentally superior gynoecium is broad and flat and consists of 10–18 connate carpels, the fertile portions of which are involute and adnate to the conical floral axis. The 8–16 ovules in each of the pocket-like locules are borne in 2 rows along the zone of adnation; placentation is axile. The short style and the style branches are lined with stigmatic tissue, which extends downward among the ovules. There is no definite stigma. The tip of the floral axis retains its meristematic characteristics beyond anthesis. In early fruit development, the rim of the floral cup grows in height, while the residual floral axis becomes a conspicuous peg-like columella. Concomitantly, the formation of numerous mucilage cells and cavities causes the ovary partitions and parts of the ovary roof to disintegrate. As a result, the seeds are contained in a single, moat-like cavity, which appears inferior. Late fruit development is characterized by the differentiation of numerous fiber sclereids in association with the extensive and complex vascular system.