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Skinner W. A. Tong H. Johnson H. Maibach H. Skidmore D. 《Cellular and molecular life sciences : CMLS》1968,24(7):679-680
Zusammenfassung Es wird gezeigt, dass menschliche Schweissabsonderungen verschiedener Versuchspersonen auf weibliche Moskitos (Aedes aegypti) verschieden attraktiv sind. Mit Diethyläther (pH 1) lassen sich im Schweiss sowohl «anlockende» wie auch «abschreckende» Bestandteile extrahieren. Für den «repellent effect» sind teilweise gleiche Mischungen von Milchsäure und Milchsäureanhydrid verantwortlich. Zwei weitere, noch nicht identifizierte Substanzen zeigten im Zwei-Kammer-Olfaktometer identische «repellent» Wirkungen.
This study was supported by U.S. Army Medical Research and Development Command, Dept. of the Army, Contracts No. DA 49-193-MD-2465 (W. Skinner) and No. DA 49-193-MD-2466 (H. Maibach). We thank Dr.L. Pope, Superintendent, and the inmates of the California Medical Faculty, Vacaville, California, USA, for their cooperation in this study. 相似文献
This study was supported by U.S. Army Medical Research and Development Command, Dept. of the Army, Contracts No. DA 49-193-MD-2465 (W. Skinner) and No. DA 49-193-MD-2466 (H. Maibach). We thank Dr.L. Pope, Superintendent, and the inmates of the California Medical Faculty, Vacaville, California, USA, for their cooperation in this study. 相似文献
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C. A. Johnson R. A. Løvstad E. Walaas O. Walaas 《Cellular and molecular life sciences : CMLS》1970,26(2):134-135
Résumé On sait que la plasmine céruléenne crystalline rétroplacentaire humaine ainsi qua la plasmine apocérulécnne empêchent l'hémaglutination virale. Cet effet pourrait être attribué aux résidus d'acide sialique, car l'action préventive disparaît après traitement de la plasmine céruléenne par la neuraminidase. 相似文献
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lambda Repressor and cro--components of an efficient molecular switch 总被引:48,自引:0,他引:48
In a lysogen, most genes of phage lambda are repressed; in response to a transient induction signal, they are efficiently switched on. The switch, which consists in part of a tripartite operator to which two regulatory proteins bind, depends not only on DNA--protein interactions, but also on effects transmitted from one DNA-bound protein to another. lambda Exemplifies a strategy that facilitates efficient switching between two physiological states in response to a transient signal. 相似文献
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Concern about biological weapons has raised questions about the most effective public health policies to contain an anthrax outbreak. We developed a probability model to predict the impact of different anthrax antibiotic and vaccination policies. An anthrax outbreak can be significantly contained by minimizing the delay until initiation of antibiotic prophylaxis. However, even if mass distribution of antibiotics is completed within six days of the initial exposure, then at most about 70% of cases can be prevented. Post-exposure vaccination will not significantly increase that prevention rate if adherence to antibiotic regimens is similar or higher than that attained in the 2001 US outbreak. However, post-exposure vaccination can be useful either in shortening the duration of a prolonged antibiotic regimen, in the event of an antibiotic-resistant strain, or if antibiotic adherence rates are very low. Here we show that a mass pre-exposure vaccination programme for the general population would require very high population coverage rates to significantly increase prevention rates from that achieved with targeted and rapid post-exposure prophylaxis programmes. 相似文献
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Removing viruses from water by polyelectrolytes 总被引:3,自引:0,他引:3
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Nonlinear grassland responses to past and future atmospheric CO(2) 总被引:17,自引:0,他引:17
Carbon sequestration in soil organic matter may moderate increases in atmospheric CO(2) concentrations (C(a)) as C(a) increases to more than 500 micromol mol(-1) this century from interglacial levels of less than 200 micromol mol(-1) (refs 1 6). However, such carbon storage depends on feedbacks between plant responses to C(a) and nutrient availability. Here we present evidence that soil carbon storage and nitrogen cycling in a grassland ecosystem are much more responsive to increases in past C(a) than to those forecast for the coming century. Along a continuous gradient of 200 to 550 micromol mol(-1) (refs 9, 10), increased C(a) promoted higher photosynthetic rates and altered plant tissue chemistry. Soil carbon was lost at subambient C(a), but was unchanged at elevated C(a) where losses of old soil carbon offset increases in new carbon. Along the experimental gradient in C(a) there was a nonlinear, threefold decrease in nitrogen availability. The differences in sensitivity of carbon storage to historical and future C(a) and increased nutrient limitation suggest that the passive sequestration of carbon in soils may have been important historically, but the ability of soils to continue as sinks is limited. 相似文献