辽宁热河生物群小龙虾化石形态特征及分类之甄别

通过上侏罗统义县组６１块龙虾标本的１２种形态特征统计分析,分别论述了其构造分类意义。利用这些保存良好的新材料,对环足虾科（Ｃｒｉｃｏｉｄｏｓｃｅｌｏｓｉｄａｅ）特征作了重要补充和修订。雄性第１腹足呈棱状,第２腹足无特化现象,是这一科的重要特征。从环足虾（Ｘｒｉｃｏｉｄｏｓｃｅｌｏｓｕｓ）和古Ｌａ蛄属（Ｐａｌａｅｏｃａｍｂａｒｕｓ）雌性都具有腹环沟构造来看,它们与古Ｌａ蛄科的关系最密切。海相的化石原     

Fluorescence ratio imaging of cyclic AMP in single cells.

Fluorescence imaging is perhaps the most powerful technique currently available for continuously observing the dynamic intracellular biochemistry of single living cells. However, fluorescent indicator dyes have been available only for simple inorganic ions such as Ca2+, H+, Na+, K+, Mg2+ and Cl-. We now report a fluorescent indicator for the adenosine 3',5'-cyclic monophosphate (cAMP) signalling pathway. The sensor consists of cAMP-dependent protein kinase in which the catalytic (C) and regulatory (R) subunits are each labelled with a different fluorescent dye such as fluorescein or rhodamine capable of fluorescence resonance energy transfer in the holoenzyme complex R2C2. When cAMP molecules bind to the R subunits, the C subunits dissociate, thereby eliminating energy transfer. The change in shape of the fluorescence emission spectrum allows cAMP concentrations and the activation of the kinase to be nondestructively visualized in single living cells microinjected with the labelled holoenzyme.     

Chronic maintenance of rat sperm reserves into old age by previous sexual contact

Summary Extensive copulatory experiences at a younger age provoked chronic changes in the reproductive physiology of old male rats. Continuous access to females was not necessary, sperm numbers were elevated in the 22-month-old males 7 months after a final sexual interaction.     

A uniform numbering system for indole alkaloids

Résumé Nous proposons un mode uniforme de numérotation pour le squelette des alcaloïdes indoliques complexes. Il est basé sur le fait que tous ces composés sont susceptibles d'être coupés en éléments identiques.

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This is a precis of a suggestion discussed at the fifth annual meeting, American Society of Pharmacognosy, Symposium on the Chemistry and Biological Activity of Catharanthus, Vinca and Related Indole Alkaloids, Pittsburgh (Pennsylvania), June, 1964.