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81.
82.
Julita Rabiza-Świder Ewa Skutnik Agata Jędrzejuk 《The Journal of Horticultural Science and Biotechnology》2017,92(3):270-278
A positive water balance is crucial for longevity of cut shoots. When water loss by transpiration exceeds water uptake by cut flowers, wilting symptoms appear. Clematis is a very attractive plant which can be used as a cut flower provided that suitable cultivars are chosen. The vase life of four cultivars tested ranged between 6.7 days and 9.0 days and the standard preservative – 200 mg·dm?3 8-hydroxyquinoline citrate (8HQC) plus 2% sucrose – prolonged it significantly in two cultivars, while 8HQC alone was efficient in only one. The preservatives delayed reduction in fresh weight. An enhancement of water uptake by the preservatives resulted in prolonged vase life of flowers in two cultivars. However, the effect of preservatives on transpiration was not related to longevity. In addition, longevity did not depend on the xylem vessel size: the cultivar with the longest vase life had the lowest average xylem vessel diameter while the cultivar with the largest vessels had an intermediate vase life. Preservatives did not always affect the number of blockages in xylem appearing during vase life. Generally, the effects of preservatives on the elements of water balance in cut shoots of clematis were not directly related to the postharvest longevity. 相似文献
83.
Studies were conducted on the effects of various kinds of teleost pituitary gonadotropins on the in vitro maturation of carp oocytes. It was ascertained that after 24 h of incubation with gonadotropins, the highest percentage of oocytes with the nucleus in the migrating or peripheral position, or of mature oocytes, was observed in the case of ciprinide gonadotropins.Centrifuged hypophysial homogenates of the pike, sea-trout and pike-perch displayed a considerably weaker activity. The results obtained are indicative of a specificity of teleost pituitary gonadotropins. 相似文献
84.
The number of Enterobacteriaceae, with particular attention given to the presence of Escherichia coli and Klebsiella pneumoniae, was determined in hospital effluents and municipal wastewater after various stages of purification. The emission of these microorganisms to the ambient air near wastewater treatment plant (WWTP) facilities and to the river water, which is a receiver of the WWTP effluent, was also studied using fluorescence in situ hybridization (FISH) and cultivation methods. The number of Enterobacteriaceae determined by cultivation and fluorescence methods in different kinds of sewage sample ranged from 0.5?×?10(3) to 2.9?×?10(6)?CFU/ml and from 2.2?×?10(5) to 1.3?×?10(8) cells/ml, respectively. Their removal rates during treatment processes were close to 99?%, but the number of these bacteria in the WWTP outflow was quite high and ranged from 5.9?×?10(3) to 3.5?×?10(4)?CFU/ml and from 1.1?×?10(5) to 6.1?×?10(5) cells/ml, respectively. In the river water and the air samples, the number of Enterobacteriaceae was also high and ranged from 4.1?×?10(3) to 7.9?×?10(3)?CFU/ml and from 3 to 458?CFU/m(3), respectively. The numbers of these microorganisms obtained from fluorescence and cultivation methods were statistically and significantly correlated; however, the analysis of the studied samples indicated that the FISH method gave values up to 10(3)-fold times greater than those obtained by the cultivation method. From a sanitary point of view, this means that the number of viable fecal bacteria is systematically underestimated by traditional culture-based methods. Thus, the FISH proves to be a method that could be used to estimate bacterial load, particularly in air samples and less contaminated river water. 相似文献
85.
86.
Purpose
The intensive development of nanotechnology raises a question of the potential consequences of the presence of nanoparticles (NPs) in the different components of the environment, including sediments. The aim of this study was to evaluate the toxicity of nanoparticles of ZnO and Ni and their bulk counterparts in bottom sediments (SD1, SD2) with different properties collected from the Vistula River in Poland.Materials and methods
Sediment samples with NPs at a concentration of 100 mg kg?1 were incubated for 17 months in the dark or under a photoperiod of 12 h light/12 h dark. The Microtox® (bacteria, Vibrio fischeri) and OSTRACODTOXKIT F? (ostracods, Heterocypris incongruens) tests were used to evaluate toxicity. In addition, the contents of Zn and Ni were determined in extracts (H2O and CaCl2) of the bottom sediments.Results and discussion
The Zn concentration was much lower in the SD1 sediment with the addition of NPs/bulk particles (30–230 μg kg?1) compared to the SD2 sediment (280–1140 μg kg?1). The toxicity of ZnO and Ni was determined by the type of bottom sediment and the parameter studied. Both nano- and bulk-ZnO and Ni caused the mortality of H. incongruens at a level of 13.3–53.3 %. The influence of ZnO and Ni on the growth of H. incongruens was observed to be the opposite. ZnO resulted in growth stimulation, while Ni resulted in growth inhibition of H. incongruens. Both ZnO and Ni stimulated V. fisheri luminescence. In most cases, the incubation of ZnO and Ni under the photoperiod increased the toxicity or decreased the stimulation of V. fisheri bioluminescence and H. ingongruens growth compared to the dark-incubated sediments.Conclusions
The study provides new and important information on the ecotoxicological effects of ZnO and Ni nanoparticles in different sediments and under various environmental conditions that may be useful for the risk assessment of this new group of contaminants.87.
In order to better understand Cu behaviour in the submontane, eutrophic Dobczyce dam Reservoir (southern Poland), speciationmeasurements of Cu in the water and the sediment were conducted. To investigate the partitioning of Cu in the main components ofthe sediment, a scheme of VI-step sequential extraction was used.In addition, other physical and chemical parameters of the water,such as temperature, pH, dissolved O2, nutrients, and suspended particulate matter were determined. Copper content in the water and the sediment was low (1.1–7.4 μg L-1 and 5.5–45.4 μg g-1, respectively). In the water Cu was usually present in the dissolved state (with the exception ofthe near-bottom water). This was probably the main reason of itssmall accumulation (cumulation coefficient K = 10687.5) in the sediment of the Dobczyce Reservoir. The seasonal variations inCu contents in the dissolved and particulate phases as well as observed correlations with the physico-chemical parameters of thewater are discussed. In the sediment Cu occurred mainly in astrongly bound form. Most Cu found there was in the moderatelyreducible phase and residual. Therefore, copper (re-)mobilization from the sediment to the water was probably not of importance. 相似文献
88.
Mats Aastrup Jacob Johnson Ewa Bringmark Iage Bringmark Åke Iverfeldt 《Water, air, and soil pollution》1991,56(1):155-167
To contribute to the understanding of Hg flow to forest lakes the storage of Hg in the soil of a catchment was quantified,
the transport of Hg from the recharge area to the discharge area was studied and a mass balance for different soil horizons
was calculated. The transport of Hg in soil, ground and stream water was estimated using water flows from a hydrological model
and by determining Hg in water sampled with a clean procedure. The estimate for the annual Hg flux out of the till overburden
in the catchment was 3.4 g km−2. The annual flux was reduced to 1.3 g km−2 in the stream, indicating interception in a lake. The transport was predominantly taking place in the upper 50 cm of the
soil. The storage of Hg in the soil was 8.8 kg km−2, which is large compared to the flux. A net accumulation, amounting to 80% of the Hg deposition, is almost entirely located
to the nor layer. 相似文献
89.
Isolation and antihypertensive effect of angiotensin I-converting enzyme (ACE) inhibitory peptides from spinach Rubisco 总被引:2,自引:0,他引:2
Yang Y Marczak ED Yokoo M Usui H Yoshikawa M 《Journal of agricultural and food chemistry》2003,51(17):4897-4902
Four new inhibitory peptides for angiotensin I-converting enzyme (ACE), that is, MRWRD, MRW, LRIPVA, and IAYKPAG, were isolated from the pepsin-pancreatin digest of spinach Rubisco with the use of HPLC. IC(50) values of individual peptides were 2.1, 0.6, 0.38, and 4.2 microM, respectively. MRW and MRWRD had an antihypertensive effect after oral administration to spontaneously hypertensive rats. Maximal reduction occurred 2 h after oral administration of MRW, whereas MRWRD showed maximal decrease 4 h after oral administration at doses of 20 and 30 mg/kg, respectively. IAYKPAG also exerted antihypertensive activity after oral administration at the dose of 100 mg/kg, giving a maximum decrease 4 h after oral administration. IAYKP, IAY, and KP, the fragment peptides of IAYKPAG, also exerted antihypertensive activity. LRIPVA [corrected] did not show any antihypertensive effect at a dose of 100 mg/kg despite its potent ACE-inhibitory activity. 相似文献
90.
Piotr Sobkowicz Ewa Tendziagolska Agnieszka Łagocka 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2020,70(4):307-317
ABSTRACTIn experiments with weed harrowing crops are negatively affected by competing weeds but also by the destructive effect of used implement. This research was carried out to find growth stages during which mixture of oat (Avena sativa L.) and triticale (× Triticosecale Wittm.) was resistant to harrowing and was able to effectively recover from this physical disturbance. Plots were harrowed 1–3 times on the same day at six consecutive stages of mixture growth with spring-tine harrow. After the latest harrowing, all plots were sprayed with herbicide to exclude competitive effect of weeds on the mixture. Compared to non-harrowed plots plant density of mixture was significantly reduced after a single cultivation at 1- and 2-leaf stage (20% and 23% respectively), two cultivations at 3-leaf stage (22%) and three at the beginning of the tillering (21%). No yield penalty was noticed for the density reductions, thus showing high ability of mixture to recover from physical disturbance. We recommend plant emergence as an appropriate growth stage for single harrowing of oat-triticale mixture. Two cultivations on the same day should not be planned earlier than at the beginning of tillering. 相似文献