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Neha Badola Ashish Bahuguna Yoel Sasson Jaspal Singh Chauhan 《Frontiers of Environmental Science & Engineering》2022,16(1):7
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Antimicrobial activity of Red Sea corals 总被引:1,自引:0,他引:1
Dovi Kelman Yoel Kashman Eugene Rosenberg Ariel Kushmaro Yossi Loya 《Marine Biology》2006,149(2):357-363
Scleractinian corals and alcyonacean soft corals are the two most dominant groups of benthic marine organisms inhabiting the coral reefs of the Gulf of Eilat, northern Red Sea. Antimicrobial assays performed with extracts of six dominant Red Sea stony corals and six dominant soft corals against marine bacteria isolated from the seawater surrounding the corals revealed considerable variability in antimicrobial activity. The results demonstrated that, while the majority (83%) of Red Sea alcyonacean soft corals exhibited appreciable antimicrobial activity against marine bacteria isolated from the seawater surrounding the corals, the stony corals had little or no antimicrobial activity. From the active soft coral species examined, Xenia macrospiculata exhibited the highest and most potent antimicrobial activity. Bioassay-directed fractionation indicated that the antimicrobial activity was due to the presence of a range of compounds of different polarities. One of these antibiotic compounds was isolated and identified as desoxyhavannahine, with a minimum inhibitory concentration (MIC) of 48 μg ml−1 against a marine bacterium. The results of the current study suggest that soft and hard corals have developed different means to combat potential microbial infections. Alcyonacean soft corals use chemical defense through the production of antibiotic compounds to combat microbial attack, whereas stony corals seem to rely on other means. 相似文献
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The fouling of quartz sleeves surrounding UV disinfection lamps is a perennial problem affecting both drinking water and wastewater applications. The mechanisms of fouling are not fully understood, but factors promoting fouling are believed to include heat, high hardness and/or high iron concentrations, and hydrodynamic forces. The role of UV radiation itself is unclear. The goal of this paper is to attempt to isolate the fouling mechanisms and to provide key information about those induced by UV radiation, using a unique laboratory-scale continuous-flow UV reactor. Its design allowed for irradiated and nonirradiated zones and control of both temperature and UV intensity at the fouling surface. Synthetic wastewater samples were tested with two levels of calcium, iron, phosphorus, and biochemical oxygen demand (as beef broth), and constant levels of magnesium and nitrogen to assess the effects of the four key variables. Average UV fluence before fouling exceeded 35 mJ/cm2, based on collimated beam tests. Foulant accumulation was monitored by UV intensity measurements and by mass and composition of foulant collected after an average of 56 hours of continuous operation. Tests showed that relative UV intensity dropped by as much as 100% when iron was present. Detailed results were assessed and yielded support for the following three UV-induced fouling mechanisms: (a) precipitation of ferric hydroxide [Fe(OH)3], (b) release of calcium from calcium-organics complexes followed by precipitation of iron-organics complexes, and (c) calcium carbonate precipitation. Other fouling mechanisms, such as sedimentation of preformed particles and sorption of calcium onto preformed colloids of Fe(OH)3, occurred outside the zone of UV radiation. Hence, these could be confused with concurrent UV-induced mechanisms in full-scale reactors. Iron and/or calcium undoubtedly created the most favorable conditions for fouling to occur; in the absence of both, fouling would be unlikely. The rates of fouling were enhanced when organics were also present; however, when phosphorus was present, fouling in the UV section was reduced. Indeed, UV may be viewed as inhibiting the fouling caused by phosphate complexes. 相似文献
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The association between ‘faint-positive’ amniotic fluid acetylcholinesterase and fetal malformations
Yoel Sadovsky MD Michelle L. Robbin Barbara F. Crandall Roy A. Filly Mitchell S. Golbus 《黑龙江环境通报》1993,13(11):1071-1074
The finding of a ‘faint-positive’ acetylcholinesterase band in amniotic fluid samples of women at 15 weeks' gestation or above is associated with an increased risk of fetal abnormalities, most commonly gastroschisis. This finding warrants a targeted sonographic evaluation, in order to rule out significant fetal malformations. 相似文献
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Bad odours are often dispersed from chemical industries, waste dumps, sewer plants, and other facilities. They are indicative of pollution emissions from these sites and cause discomfort, apprehension, and sometimes signal the presence of health hazards. Monitoring the pollution by direct means, such as chemical analysis of ambient air, is obviously the most reliable mechanism to acquire data regarding pollution. However, this is not always possible. In this paper we report on the value of local government hotlines that record information provided by the public regarding bad odours. These data can alert the authorities to the existence of pollution and should be regarded as potentially useful when collected in conjunction with information from automated weather stations. An analysis of data from the Be'er Sheva municipality and the Ramat Negev regional council hotlines is provided. Complaints recorded by these systems were correlated with weather data from local automatic weather stations to indicate the sources of the bad odours. Wind direction was found to be highly correlated with bad odour and pollution sources, revealing consistent patterns in terms of the time of day and weather conditions. 相似文献
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