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981.
The endophytic fungus Coniothyrium sp. was isolated from leaves of Quercus robur. Fermentation of this fungus on solid rice medium yielded two new furoic acid derivatives ( 1 and 2 ) and two additional known compounds. The structures of the new compounds were determined by extensive analysis of 1D and 2D nuclear magnetic resonance spectra as well as high-resolution mass spectrometry data. Compound 1 , containing three aromatic chromophores attached by rotatable sigma bonds and a chirality center in benzylic position, was found to be a scalemic mixture with an excess of the (S) enantiomer, the absolute configuration of which was elucidated as by the solution time-dependent density functional theory-electronic circular dichroism approach. The ωB97X/TZVP PCM/MeCN and SOGGA11-X/TZVP SMD/MeCN methods were used for geometry reoptimization to reproduce the solution conformational ensemble. All isolated compounds were tested for their cytotoxicity but proved to be inactive.  相似文献   
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Libri novi     
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986.
The aim of this paper is to address the question of how informationtransfer affects foraging efficiency in a colonial breedingsituation. By creating computer simulations, we attempt to modelinformation transfer of food location by individuals withinthe colony. Three kinds of foraging strategy were modeled: searcher–noinformation transfer (solo foraging), watcher–limitedinformation transfer (local enhancement), and a mixture of watcherand follower–full information transfer (information center).The predictability of food was changed by varying patchiness(ratio of food patches) and duration of food patches. When thefood occurs in many randomly distributed patches and the fooddensity in each is low, the solitary searcher strategy givesthe best foraging efficiency. The significance of informationtransfer strategies and colonial breeding on foraging efficiencyincrease when food becomes more clumped. The solitary watcherstrategy is the best at intermediately clumped food distribution.Colonial breeding gives the best foraging efficiency when theinformation center operates and there are some high-densityfood patches.  相似文献   
987.
We have analysed the influence of human malignant, inflammatory and infectious disease on the capacity of peripheral lymphocytes to mediate antibody-dependent haemolysis. The application of an enzyme-like kinetic model for measurement of maximal cytotoxic function has permitted reproducible and sensitive determinations of the K-cell function. The results show that malignant disease is associated with enhancement of ADCC capacity.  相似文献   
988.
Tibor Benedek 《Mycopathologia》1956,7(3-4):251-256
Summary Mycelial forms in the parasitic life cycle ofC. immitis have been reported several times. These observations are confirmed by the findings of the author. Mycelia and coremium formation of the mycelia (this latter never reported before) of C. immitis were found in the pus of a huge abscess in a patient suffering for many years from coccidioidal granuloma of the lungs. Mycelia were also present in the serum of a cantharides blister, a proof of their presence in the circulation. The development of mycelial forms in the animal tissue must be, thus, considered as an established fact.Budding in the life cycle ofC. immitis in vivo and in vitro have also been reported before. The author, from his own observation, can confirm the correctness of this finding beyond doubt. Thus, budding of the organism in the animal tissue cannot any longer be considered as a cardinal difference between B, dermatitidis and C, immitis.  相似文献   
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