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861.
Summary 1-O-Monoalkylglycerols with C12 to C20 chains were identified in the scent, gland secretions of the western diamondback rattlesnake (Crotalus atrox). This is the first documentation of these compounds in the skin secretions of a reptile.  相似文献   
862.
吉林市冬季冰雪旅游资源开发初探   总被引:1,自引:0,他引:1  
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863.
J Nwoga  E E Bittar 《Experientia》1989,45(2):142-143
Single muscle fibers of the barnacle Balanus nubilus have been used as a preparation to test the possibility that the Rp-diastereomer of adenosine cyclic 3',5'-phosphorothioate, which is the first available analog of cAMP that acts as an antagonist of cAMP, may reduce the magnitude of cAMP-mediated stimulation of the resting ouabain-insensitive Na efflux. The results obtained show that this antagonist is, in fact, able to reduce stimulation of the Na efflux by injected cAMP in a dose-dependent manner.  相似文献   
864.
Summary Preliminary experiments carried out in the Granada province of Southern spain over three years and in three different habitats have shown that a single application of Ethrel (2 chloro-ethyl phosphonic acid) to the olive tree at the beginning of fruit formation is sufficient to reduce significantly attack byPrays oleae Bern. and subsequent damage to the fruit. At the same time the treatment did not cause any detrimental change to the trees and had no measurable effect on the activity of beneficial insects such as Chrysopids (Neuroptera), which are known to be importantP. oleae egg predators in the study area.  相似文献   
865.
866.
Summary Luffolide (4) is a minor metabolite of the spongeLuffariella sp. from Palau. The structure of luffolide was determined by single crystal X-ray analysis. Luffolide is relatively unstable and undergoes a complex cyclization reaction to give the hexacyclic products5 and6. Luffolide (4) has some of the anti-inflammatory properties of manoalide (1): this may help to define the chemical reaction between manoalide (1) and phospholipase A2.All crystallographic calculations were done on a PRIME 9950 computer operated by the Cornell Chemistry Computing Facility. Principal programs employed were: FOBS, a data reduction program by G.D. Van Duyne, Cornell University, 1987; MULTAN 80, and RANTAN 80, systems of computer programs for the automatic solution of crystal structures from X-ray diffraction data (locally modified to perform all Fourier calculations including Patterson syntheses) written by P. Main, S. E. Hull, L. Lessinger, G. Germain, J. P. Declercq and M. M. Woolfson, University of York, England, 1980 BDLS, an, anisotropic block diagonal least squares refinement written by K. Hirotsu, E. Arnold, and G. D. Van Duyne, Cornell University, 1987; PLUTO 78, a locally modified crystallographic illustration program by W. D. S. Motherwell, Cambridge Crystallographic Data Centre, 1978; and BOND, a program to calculate molecular parameters and prepare tables written by K. Hirotsu and G. Van Duyne, Cornell University, 1985.Acknowledgment. We thank the Government of the Republic of Palau for a scientific research permit. We thank Dr Klaus Rützler, Smithsonian Institution, Washington, D.C. for identifying the sponge and Mary Kay Harper for performing additional bioassays. This research was supported by grants from the Sea Grant College Programs of California [Projects R/MP-30 to DJF) and R/MP-31 (to RSJ)] and New York (to JC) and the National Institutes of Health (CA 24487 to JC).  相似文献   
867.
868.
Summary The pineal of lower vertebrates characteristically contains true and modified photoreceptors with functional und structural homologies to retinal photoreceptors. Afferent nerves convey photic information from the pineal to sensory areas of the brain stem. Light also influences synthetic activity within the organ, controlling the rhythm in melatonin production which is generated endogenously. The molecular mechanisms underlying this rhythmic event are described and the hypothesis advanced that the pineal transduces several forms of environmental stimulus involved in the regulation of rhythmic function.  相似文献   
869.
This issue of EXPERIENTIA on ‘Developments in Biotechnology’ is dedicated to Professor Armin Fiechter who celebrated his 65th birthday in October. He is one of the most eminent promoters of biotechnology in Switzerland and he was instrumental in establishing the Institute for Biotechnology at ETH in 1982 of which he is still director. By pioneering the combination of fundamental and applied aspects he has greatly influenced the advancement of biotechnology in teaching and research in Switzerland. Distinguished scientists from various countries were invited to contribute to this special issue of EXPERIENTIA to review aspects of yeast physiology, process optimization and control, analytics, and applications. We are well aware that the articles presented here are only a narrow selection of the current activities in biotechnology but since Professor Fiechter has devoted most of his scientific career to research on yeast physiology, process development and instrumentation it is appropriate to focus this issue on these aspects. We thank all the authors who have contributed to mark this special event. Professor Fiechter continues to actively stimulate progress in biotechnology with a still lively awareness of future developments. May he continue to persue his objectives and, together with Mrs. Fiechter, enjoy the time to come.  相似文献   
870.
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