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排序方式: 共有841条查询结果,搜索用时 15 毫秒
831.
832.
833.
Effect of cadmium on composition and diversity of bacterial communities in activated sludges 总被引:3,自引:0,他引:3
Yung-Pin Tsai Sheng-Jie You Tzu-Yi Pai Ko-Wei Chen 《International biodeterioration & biodegradation》2005,55(4):285-291
Microbial communities of two kinds of activated sludge for removing carbon, nitrogen and phosphate (nutrient removal sludge) were identified and compared by combining cloning–denaturing gradient gel electrophoresis methods. The sludges were sampled in an anaerobic–anoxic–oxic system operating under the same conditions, except for one without the addition of cadmium (Cd0) and the other with addition of 5 mg cadmium l−1 (Cd5). Bacteria in the phylum Proteobacteria were predominant in both Cd0 and Cd5 sludges (39.6% and 35.1% of total bacteria, respectively). However, bacteria in the class Betaproteobacteria were significantly more abundant in Cd0 than in Cd5 sludge (30.7% and 2.1%, respectively). Species related to nutrient removal, such as nitrifying bacteria (Nitrosomonas communis), floc-forming bacteria (Zoogloea ramigera) and phosphate-accumulating organisms (Rubrivivax gelatinosus), were the predominant species in Cd0 sludge, but were not found in Cd5 sludge. Cadmium was significantly toxic to the bacterial community in nutrient removal sludge, especially to the bacteria in the Betaproteobacteria. The comparison of microbial communities between these two kinds of sludge was further discussed in the paper. 相似文献
834.
Roberto Memeo Petra Paiè Federico Sala Michele Castriotta Chiara Guercio Thomas Vaccari Roberto Osellame Andrea Bassi Francesca Bragheri 《Journal of biophotonics》2021,14(3):e202000396
We present a microscope on chip for automated imaging of Drosophila embryos by light sheet fluorescence microscopy. This integrated device, constituted by both optical and microfluidic components, allows the automatic acquisition of a 3D stack of images for specimens diluted in a liquid suspension. The device has been fully optimized to address the challenges related to the specimens under investigation. Indeed, the thickness and the high ellipticity of Drosophila embryos can degrade the image quality. In this regard, optical and fluidic optimization has been carried out to implement dual-sided illumination and automatic sample orientation. In addition, we highlight the dual color investigation capabilities of this device, by processing two sample populations encoding different fluorescent proteins. This work was made possible by the versatility of the used fabrication technique, femtosecond laser micromachining, which allows straightforward fabrication of both optical and fluidic components in glass substrates. 相似文献
835.
S H Pai H J Rahmsdorf H Ponta M Hirsch-Kauffmann P Herrlich M Schweiger 《European journal of biochemistry》1975,55(1):305-314
Protein kinase, which was isolated from cells infected with T7, is indeed a viral gene product. This is shown by DNA-dependent synthesis in vitro. The protein kinase transfers phosphate from ATP to seryl or threonyl residues in protein. The enzyme has only a relative requirement for magnesium ions, but is only active at low ionic strength. The best substrate is lysozyme. T7 protein kinase activity is not stimulated by cyclic 3':5'-AMP and/or cyclic 3':5'-GMP. The T7 protein kinase carries -- SH groups essential for activity. There is indication that the enzyme phosphorylates itself and causes self inactivation, which may explain the fast disappearance of enzyme activity in vivo. Bacteriophage T3 also induces a protein kinase which is similar to the T7-induced enzyme in all respects tested. 相似文献
836.
Naomi Kondo Akira Takao Geng Pai Li Naoki Kuwabara Hidehiko Fujii Tadao Orii 《Biotherapy》1993,6(4):279-282
To assess the ability of immunoglobulin production in vivo, we enumerated the immunoglobulin secreting cells in the peripheral blood of patients with an IgA deficiency and of those with hyper-IgAemia. All seven patients with primary IgA deficiency and two of the three patients with secondary IgA deficiency had low numbers of IgA secreting cells. In all five patients with hyper-IgA the number of IgA secreting cells was increased. Our results suggest that measurement of immunoglobulin secreting cells in PBMCs is useful in the assessment of ability of immunoglobulin production in vivo.Abbreviations PBMCs
peripheral blood mononuclear cells
- MEM
minimum essential medium
- PFC
plaque forming cells
- VH
immunoglobulin heavy chain variable region
- CH
immunoglobulin heavy chain constant region 相似文献
837.
838.
839.
The mutagenic activity of several arylamines, alkyl- and arylcarbamates and their corresponding N-hydroxylated derivatives towards Escherichia coli WP2uvrA was investigated using the fluctuation test without a metabolic activation system. None of the parent amines or carbamates were mutagenic while several arylhydroxylamines and N-hydroxycarbamates were direct-acting base-pair substitution mutagens. With the exception of n-hexyl-N-hydroxycarbamate, the mutagenic activity of the N-hydroxycarbamates increased with increase in the length of alkyl substituent. Some arylamines and arylhydroxylamines were further examined, again without a metabolic activation system, using a plate test in conjunction with bacterial strains which detect either base-pair or frameshift mutagens. The arylhydroxylamines were found to cause both base-pair and frameshift mutations but were more active as frameshift mutagens. Possible reasons for the observed mutagenic activity are considered. 相似文献
840.
K W Lee H C Suhk K S Pai H J Shin S Y Jung E T Han J Y Chai 《The Korean journal of parasitology》2001,39(4):319-321
Diphyllobothrium latum infection in human is not common in Korea and only thirty seven cases have been reported since 1921. We report two cases of fish tapeworm infection after ingestion of raw cherry salmon (Oncorhynchus masou) caught in the domestic river. Among four family members who ate together raw salmon flesh six months ago, just two, mother and daughter, were infected. It is our expectation that the salmon associated tapeworm infections would be enlisted as one of the major parasitic problems with the growing consumption of salmon in Korea. 相似文献