近现代中国农业科学技术发展回顾与展望

本文回顾了近现代中国农业科学院技术发展的历程，阐述了中国农业科学技术发展取得的成就，总结了半个世纪以来中国农业科技进步的主要特征，对21世纪中国农业发展前景进行了分析展望，作者认为，坚持共产党的领导，走社会主义道路，中国才结束了积贫积弱的历史，才实现中国历史上最广泛最深刻的社会，才使中国人民掌握了自己的命运，中国基本解决温饱问题，支撑现代化建设两步走战略目标的提前实现，一个很重要的因素就是科学技术取得长足的进步，对农业、农村发展做出了重要贡献，21世纪，中国农业担负的任务要比改革开放20年来解决温饱进入小康更为繁重，这是中国现代化进程中最艰巨的历史性任务，科学技术的跨越发展将为21世纪中国实现农业现代化发挥决定性的作用。     

Structures and molecules involved in generation and regulation of biological rhythms in vertebrates and invertebrates

Melatonin from the retina and the pineal gland functions in neuroendocrine hierarchies. Photoreceptors — eyes and extraretinal — detect light. Oscillators — pineal and suprachiasmatic nuclei — act as pacemakers. Driven neuroendocrine rhythms carry temporal hormone signals throughout the body. Light controls melatonin: light sets the phase of the melatonin rhythm and determines the duration of melatonin synthesis. By these means, circadian rhythms (e.g. in locomotor activity and body temperature) and seasonal rhythms (e.g. in reproduction) are controlled.     

Secretion of cytokinins in vivo and in vitro byAlternaria brassicicola and their role in pathogenesis

Summary Formation of green islands in the host (mustard leaves) beneath the infection-drops containing germinating conidia ofAlternaria brassicicola (Schw.) Wiltsch. has been correlated with the secretion of cytokinins by the pathogen.A. brassicicola also synthesized cytokinins in the liquid synthetic medium. Cytokinins produced in vitro were extracted, and their application on the detached mustard leaves evoked the formation of green islands.     

Differences in the content and turnover of noradrenaline in rat heart atria and ventricles and circadian-phase-dependency

In light-dark-synchronized male rats the levels of noradrenaline in heart atria were about 3 times that found in heart ventricles. Noradrenaline turnover rate which were about 8-9 fold greater for the atria than for the ventricles displayed a circadian-phase-dependency with increased rates in the dark period in both parts of the rat heart.     

Formation of proviruses in acute infection in vitro and in vivo

Summary Formation of DNA proviruses of RNA viruses, Sendai and Newcastle disease, was studied. DNA provirus of NDV was shown to be formed in mouse L-cells and Sendai DNA provirus in Ehrlich ascites carcinoma cells within 2–3 days post infection.     

Studies of total and protein-bound plasma Mg++ in wild and hatchery-reared coho salmon smolts in freshwater and in seawater

Summary Total plasma Mg⁺⁺ and Ca⁺⁺, Mg⁺⁺ in erythrocytes as well as protein-bound plasma Mg⁺⁺ were investigated in wild and hatchery-reared smolts. The proportion of plasma Mg⁺⁺ which was bound to plasma protein did not change significantly during entry into seawater, even though the in vitro addition of exogenous Mg⁺⁺ to the plasma showed that additional binding was possible.     

The thorium-series in cigarettes and in lungs of smokers

Résumé Le spectre de cigarettes courantes révèle systématiquement la série radioactive du thorium, à raison de 9 à 36 mg de²³²Th-equiv. pour 9000 cigarettes, la consommation annuelle d'un grand fumeur. Dans l'anthropospectromètre, le thorax de la moitié des fumeurs mesurés montre les raies de la même série avec 1,7 à 2,4 ± 0,6 mg de²³²Th-équiv. par sujet.

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Theses researches were performed before leaving this laboratory mid-January 1970. Paper delivered at 12ème Table Ronde sur l'exploration fonctionnelle par les isotopes radioactifs on May 23, 1970, Strasbourg.     

Co-polymerization of dopa and cysteinyldopa in melanogenesis in vitro

Summary Tyrosinase oxidation of dopa in the presence of varying amounts of 5-S-cysteinyldopa led to the production of pigments whose chemical and physical (colour and solubility) properties are intermediate between those of pure eumelanin-and phaeomelanin-type pigments.Acknowledgment. This work was supported in part by a grant from CNR, Rome, within the frame of the project Controllo della crescita neoplastica.     

Starvation and penetration of bacteria in soils and rocks

Summary The soil and subsurface strata are low nutrient environments and their bacterial inhabitants must adopt starvation responses to survive. These responses include the formation of dormant, viable cells which, although reduced in cell size and volume, are able to respond to any improvement in nutrient availability. Starved bacteria are able to survive for extended periods without nutrients and their reduced size allows them to disperse deeply within rocks and soils greatly improving their penetration. These combined factors may increase opportunities for bacteria to reach a deep waste disposal site.     

The differences in the accumulation and metabolism of catechol amines in heart and liver

Zusammenfassung Noradrenalin und Adrenalin werden von Katzen nach simultaner intravenöser Darreichung zum Teil unverändert in der Leber und anderen Organen gespeichert, jedoch nicht im Herzen. Nach Vorbehandlung der Tiere mit Iproniazid wird im Herzen ebenfalls eine Anhäufung der beiden Hormone gefunden.Es wird auch eine relativ grössere Inaktivierung des Adrenalins im Vergleich zu Noradrenalin festgestellt.

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This investigation supported by grants from Nat. Inst. Health, and presented in part to Fed. Amer. Soc. for exp. Biol., Chicago, April 1960.