排序方式: 共有29条查询结果,搜索用时 718 毫秒
1.
2.
3.
Bunge M Adrian L Kraus A Opel M Lorenz WG Andreesen JR Görisch H Lechner U 《Nature》2003,421(6921):357-360
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) are among the most notorious environmental pollutants. Some congeners, particularly those with lateral chlorine substitutions at positions 2, 3, 7 and 8, are extremely toxic and carcinogenic to humans. One particularly promising mechanism for the detoxification of PCDDs and PCDFs is microbial reductive dechlorination. So far only a limited number of phylogenetically diverse anaerobic bacteria have been found that couple the reductive dehalogenation of chlorinated compounds--the substitution of a chlorine for a hydrogen atom--to energy conservation and growth in a process called dehalorespiration. Microbial dechlorination of PCDDs occurs in sediments and anaerobic mixed cultures from sediments, but the responsible organisms have not yet been identified or isolated. Here we show the presence of a Dehalococcoides species in four dioxin-dechlorinating enrichment cultures from a freshwater sediment highly contaminated with PCDDs and PCDFs. We also show that the previously described chlorobenzene-dehalorespiring bacterium Dehalococcoides sp. strain CBDB1 (ref. 3) is able to reductively dechlorinate selected dioxin congeners. Reductive dechlorination of 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD) demonstrates that environmentally significant dioxins are attacked by this bacterium. 相似文献
4.
5.
P. Kraus 《Cellular and molecular life sciences : CMLS》1968,24(2):206-208
Zusammenfassung Beschreibung einer Ultramikromethode zur Bestimmung der Glutaminsäure-dekarboxylase, welcher die Aktivitätsmessung des durch die enzymatische Reaktion entstandenen14CO2 zugrunde liegt. Die Reaktion wird in einem Spezialgefäss durchgeführt. 相似文献
6.
Zusammenfassung 4-Acetaminobenzoesäure hatin vitro im Unterschied zu 4-Aminobenzoesäure, keinen günstigen Einfluss auf die antituberkulotische Wirkung von Isoniazid. Bei den StämmenMycobacterium 607 und H37Rv wurde jedoch chromatographisch keine Bildung acetylierter 4-Aminobenzoesäure nachgewiesen. 相似文献
7.
PR Steinmetz JE Kraus C Larroux JU Hammel A Amon-Hassenzahl E Houliston G Wörheide M Nickel BM Degnan U Technau 《Nature》2012,487(7406):231-234
Striated muscles are present in bilaterian animals (for example, vertebrates, insects and annelids) and some non-bilaterian eumetazoans (that is, cnidarians and ctenophores). The considerable ultrastructural similarity of striated muscles between these animal groups is thought to reflect a common evolutionary origin. Here we show that a muscle protein core set, including a type II myosin heavy chain (MyHC) motor protein characteristic of striated muscles in vertebrates, was already present in unicellular organisms before the origin of multicellular animals. Furthermore, 'striated muscle' and 'non-muscle' myhc orthologues are expressed differentially in two sponges, compatible with a functional diversification before the origin of true muscles and the subsequent use of striated muscle MyHC in fast-contracting smooth and striated muscle. Cnidarians and ctenophores possess striated muscle myhc orthologues but lack crucial components of bilaterian striated muscles, such as genes that code for titin and the troponin complex, suggesting the convergent evolution of striated muscles. Consistently, jellyfish orthologues of a shared set of bilaterian Z-disc proteins are not associated with striated muscles, but are instead expressed elsewhere or ubiquitously. The independent evolution of eumetazoan striated muscles through the addition of new proteins to a pre-existing, ancestral contractile apparatus may serve as a model for the evolution of complex animal cell types. 相似文献
8.
O. Benešová J. Hvizdošová J. Musil M. Kraus R. Erdösová 《Cellular and molecular life sciences : CMLS》1976,32(11):1446-1447
Summary Cholinesterase reactivators — trimedoxim, methoxim and obidoxim — injected in the dose of 20 mg/kg s.c., increase muscle glycogen concentration in normal, but not in adrenalectomized rats. This effect may be in connection with simoultaneously found rise of serum corticosteron level. Trimedoxim decreases adrenaline, methoxim and obidoxim noradrenaline concentration in adrenals. 相似文献
9.
10.