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排序方式: 共有899条查询结果,搜索用时 15 毫秒
1.
2.
Biodegradation by activated sludge and toxicity of tetracycline into a semi-industrial membrane bioreactor 总被引:1,自引:0,他引:1
Much attention has been devoted recently to the fate of pharmaceutically active compounds such as tetracycline antibiotics in soil and water. Tetracycline (TC) biodegradability by activated sludge derived from membrane bioreactor (MBR) treating swine wastewater via CO2-evolution was evaluated by means of modified Sturm test, which was also used to evaluate its toxicity on carbon degradation. The impact of tetracycline on a semi-industrial MBR process was also examined and confronted to lab-scale experiments. After tetracycline injection in the pilot, no disturbance was detected on the elimination of organic matters and ammonium (nitrification), reaching after injection 88% and 99% respectively; only denitrification was slightly affected. Confirming the ruggedness and the superiority of membrane bioreactors over conventional bioreactors, no toxicity was observed at the considered level of TC in the pilot (20 mg TOC L−1), while at lab-scale sodium benzoate biodegradation was completely inhibited from 10 mg TOC L−1 TC. The origin of the activated sludge showed a significant impact on the performances, since the ultimate biodegradation was in the range −50% to −53% for TC concentrations in the range 10–20 mg TOC L−1 with conventional bioreactor sludge and increased to 18% for 40 mg TOC L−1 of TC with activated sludge derived from the MBR pilot. This confirmed the higher resistance of activated sludge arising from membrane bioreactor. 相似文献
3.
Environmental contributions to variation on menarcheal age were studied in 2018 Spanish girls and women from de Province of
Cuenca. (Spain). This province has a big variation in altitude and is one of the most representative as middle-altitude population
in Spain. Maturation's delay in high populations is well referenced but there are less studies in European middle-altitude
populations. To give news about this topic is the main objective of this paper. Retrospective Method was employed in adult
sample and Status-Quo in young population (9 to 15 years old) Another social, nutritional, somatic and educational levels
was recording to give a variation contest. Our study shows a significantly variation between the provincial areas. In effect,
the population of “Sierra”, the mountain region has the last maturation in the adults (13.45±0.73) as well as in girls (13.26±1.07).
Secular change was observed in relation with this parameter., but less intense that in total, of province. We can confirm
the utility of the age of menarche as evaluator of human variation in time and ecological situations. 相似文献
4.
M. B. Bianchi S. A. Harris P. E. Gibbs D. E. Prado 《Plant Systematics and Evolution》2005,251(2-4):173-181
We estimated the outcrossing rate in a population of 14 individuals of Dolichandra cynanchoides (Bignoniaceae), a species with late-acting self-incompatibility (LSI), at a site in Chaco woodland in Santa Fe province, Argentina. A subsample of five arbitrarily chosen loci from a total of 16 allozyme loci gave mating system parameters of tm=0.881 (SD 0.039) and ts=0.749 (SD 0.048), thus indicating that although predominantly outcrossing, D. cynanchoides has a mixed mating system. We draw attention to the fact that mixed mating in species with LSI is a very likely scenario, given that previous studies with diverse LSI taxa have shown that mixed cross-self pollen loads on the stigma, which is probably a common occurrence with natural pollinators, result in fruits with a proportion of selfed seeds. 相似文献
5.
M. Sazima S. Vogel A. L. do Prado D. M. de Oliveira G. Franz I. Sazima 《Plant Systematics and Evolution》2001,227(3-4):195-208
The pollination biology of the neotropical scandent shrub Combretum lanceolatum was studied in the seasonally-flooded Pantanal region in western Brazil. This plant bears horizontally oriented inflorescences,
whose yellowish green flowers begin to expand at dusk and are fully open at dawn. Instead of fluid nectar the flowers produce
sweet gelatinous secretion in form of pellets. The glandular complex of the flower is composed of the inner wall of the receptacle
and its tubular extension, being equivalent to the nectariferous disk of the nectar-producing species within the genus. The
jelly is produced at night, contains mannan and is imbibed by free hexoses. It originates by swelling and disintegration of
the inner wall, after contact with the nectar generated concomitantly in the mesophyll. Combretum lanceolatum is unique within the genus in its production of jelly pellets instead of liquid nectar. A new term, the jelly-flower, is
proposed for flowers with this kind of reward. The pellet is not replaced once removed by a bird, and thus resembles a fruit
in its availability to consumers, another unique feature that distinguishes this species within the genus. The jelly pellets
offered by the many flowered branches attract a great diversity of bird visitors (28 species from eight families), which feed
on this copious food resource and pollinate the flowers. The most effective pollinators probably are thrushes, tanagers, and
orioles. Flocking parakeets and macaws sometimes feed on the petals, thus acting as flower plunderers. Combretum lanceolatum presents a high fruit set under natural conditions, which likely favours its spreading and becoming a weed species.
Received July 11, 2000 Accepted November 18, 2000 相似文献
6.
Oliveira Jairo P. Prado Adilson R. Keijok Wanderson J. Valotto Rafaela S. Silva André R. Guimarães Marco C. C. 《Plasmonics (Norwell, Mass.)》2019,14(3):743-753
Plasmonics - Nano-surface modification techniques have been increasingly reported in a multitude of applications. However, the metal-ligand interface can be difficult to characterize, mainly due to... 相似文献
7.
Marina T. Durand Christiane Becari Mauro de Oliveira Jussara M. do Carmo Carlos Alberto Aguiar Silva Cibele M. Prado Rubens Fazan Jr Helio C. Salgado 《PloS one》2014,9(8)
The effect of pyridostigmine (PYR) - an acetylcholinesterase inhibitor - on hemodynamics and cardiac autonomic control, was never studied in conscious myocardial infarcted mice. Telemetry transmitters were implanted into the carotid artery under isoflurane anesthesia. Seven to ten days after recovery from the surgery, basal arterial pressure and heart rate were recorded, while parasympathetic and sympathetic tone (ΔHR) was evaluated by means of methyl atropine and propranolol. After the basal hemodynamic recording the mice were subjected to left coronary artery ligation for producing myocardial infarction (MI), or sham operation, and implantation of minipumps filled with PYR or saline. Separate groups of anesthetized (isoflurane) mice previously (4 weeks) subjected to MI, or sham coronary artery ligation, were submitted to cardiac function examination. The mice exhibited an infarct length of approximately 12%, no change in arterial pressure and increased heart rate only in the 1st week after MI. Vagal tone decreased in the 1st week, while the sympathetic tone was increased in the 1st and 4th week after MI. PYR prevented the increase in heart rate but did not affect the arterial pressure. Moreover, PYR prevented the increase in sympathetic tone throughout the 4 weeks. Concerning the parasympathetic tone, PYR not only impaired its attenuation in the 1st week, but enhanced it in the 4th week. MI decreased ejection fraction and increased diastolic and systolic volume. Therefore, the pharmacological increase of peripheral acetylcholine availability by means of PYR prevented tachycardia, increased parasympathetic and decreased sympathetic tone after MI in mice. 相似文献
8.
Rocío Prado Vega Peter M. van Leeuwen Elizabeth Rendón Vélez Hans G. Lemij Joost C. F. de Winter 《PloS one》2013,8(10)
The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23) and control participants (n = 12) completed four 5-min driving sessions in a simulator. The participants were instructed to maintain the car in the right lane of a two-lane highway while their speed was automatically maintained at 100 km/h. Additional tasks per session were: Session 1: none, Session 2: verbalization of projected letters, Session 3: avoidance of static obstacles, and Session 4: combined letter verbalization and avoidance of static obstacles. Eye-scanning behavior was recorded with an eye-tracker. Results showed no statistically significant differences between patients and control participants for lane keeping, obstacle avoidance, and eye-scanning behavior. Steering activity, number of missed letters, and letter reaction time were significantly higher for glaucoma patients than for control participants. In conclusion, glaucoma patients were able to avoid objects and maintain a nominal lane keeping performance, but applied more steering input than control participants, and were more likely than control participants to miss peripherally projected stimuli. The eye-tracking results suggest that glaucoma patients did not use extra visual search to compensate for their visual field loss. Limitations of the study, such as small sample size, are discussed. 相似文献
9.
Abstract Post-construction avifauna investigations were undertaken at Project West Wind, Meridian Energy Limited's 62-turbine wind farm on the Wellington south coast. These investigations were required in accordance with the resource consent conditions to quantify the level of avian mortalities occurring at the wind farm, particularly in regard to New Zealand falcon (Falco novaeseelandiae), kākā (Nestor meridionalis) and kererū (Hemiphaga novaeseelandiae). This is the first comprehensive study at a New Zealand operating wind farm. The methods included three field components necessary to calculate annual estimates of mortalities across the wind farm site: routine turbine searches; carcass detection trials; and carcass removal trials. Results from years 1 and 2 of a three-year programme are presented. To date, mortalities have been recorded for 17 taxa at 18 of the 24 study turbines. There have been no recorded mortalities of falcon, kākā or kererū. Australasian harrier (Circus approximans) has been the species for which the most mortalities have been recorded. Overall estimated annual mortality rates for years 1 and 2 were calculated to be approximately six and five birds per turbine respectively. 相似文献
10.
Catarina Prado e Castro José Paulo Sousa María Isabel Arnaldos João Gaspar María Dolores García 《法国昆虫学会纪事》2013,49(1-2):128-139
The first forensic entomological study performed in Portugal is presented. Two piglet (Sus scrofa L.) carcasses were used to determine adult Calliphoridae activity on carrion over a period of 121 days, all along the end of spring and the summer, both in a shaded and a sunny site. Five decomposition stages were observed and a total of 10723 adult Calliphoridae, belonging to 11 species, were collected. Calliphora vicina, Calliphora vomitoria, Chrysomya albiceps and Lucilia caesar were the dominant species in this study. Decomposition was faster on the carcass exposed to the sun and the number of Calliphoridae specimens was higher there than in the shaded site. It was found a significant effect of the decomposition stage in the number of specimens attracted to the carcass, as well as a significant effect of the interaction between the decomposition stage and insolation regime. Calliphora and Lucilia species did not show preference for sunny or shaded areas. Important differences in the Calliphoridae community structure were found compared to other regions of the Iberian Peninsula, reinforcing the need of further studies in different environments and regions of this geographical area in order to collect information about the local necrophagous fauna used in forensic practice. 相似文献