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排序方式: 共有2344条查询结果,搜索用时 15 毫秒
31.
Sawomir Krejszeff Dariusz Kucharczyk Krzysztof Kupren Katarzyna Targoska rzej Mamcarz Roman Kujawa Zbigniew Kaczkowski & Sebastian Ratajski 《Aquaculture Research》2008,39(9):907-912
Research into artificial reproduction of chub was studied during three subsequent reproductive seasons. Chub reproduction was conducted in two different variations. In the first experiment different hormonal agents were given to fish, such as CPE, hCG, or an analogue of GnRH with dopamine antagonist (ovopel). In the second one, the optimum moment of applying of artificial reproduction was sought and the fish were only obtained an analogue of GnRH in different periods. The results obtained in two first seasons indicated that ovopel is the most effective agent for the artificial reproduction of chub. Consequently, it was decided that the fish would obtain only this agent in the final year of research. In last year (experiment II), chub spawners were taken to the hatchery under controlled conditions every few weeks from February to the beginning of June. Periodically, the maturity of oocytes was checked. As soon as the oocytes had achieved stage 2–3 of maturity, fish were obtained ovopel. It was noted that there was no problem with collecting semen. Obtaining oocytes was much more difficult. Most frequently, they were not obtained at all or obtained in very small amounts. It was also observed that the administration of hormones caused a very quick maturation of gonads and their over-maturation. 相似文献
32.
ABSTRACT: As part of this study on the isolation of cholinesterase inhibitors from natural marine products, the bioactivity of the ethanolic extracts from 27 Korean seaweeds were screened using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory assays. Ecklonia stolonifera exhibited promising inhibitory properties against both AChE and BChE. Bioassay-guided fractionation of the active n -hexane and ethyl acetate (EtOAc) soluble fractions, obtained from the ethanolic extract of E. stolonifera , resulted in the isolation of the sterols; fucosterol ( 1 ) and 24-hydroperoxy 24-vinylcholesterol ( 2 ), from the n -hexane fraction and the phlorotannins; phloroglucinol ( 3 ), eckstolonol ( 4 ), eckol ( 5 ), phlorofucofuroeckol-A ( 6 ), dieckol ( 7 ), triphlorethol-A ( 8 ), 2-phloroeckol ( 9 ) and 7-phloroeckol ( 10 ), from the EtOAc fraction. Of these, compounds 2 , 9 and 10 were isolated from E. stolonifera for the first time. Compounds 4 – 7 , 9 and 10 exhibited inhibitory potential against AChE, with 50% inhibition concentration (IC50 ) values of 42.66 ± 8.48, 20.56 ± 5.61, 4.89 ± 2.28, 17.11 ± 3.24, 38.13 ± 4.95 and 21.11 ± 4.16 μM, respectively; whereas, compounds 1 , 2 , 4 and 6 were found to be active against BChE, with IC50 values of 421.72 ± 1.43, 176.46 ± 2.51, 230.27 ± 3.52 and 136.71 ± 3.33 μM, respectively. It has been suggested that the inhibition of these enzymes by the sterols and phlorotannins derived from marine brown algae could be a useful approach for the treatment of Alzheimer's disease. 相似文献
33.
Sung-Je Choi Eun-Jeong Park Hirotoshi Endo Yukihiro Kitade Naotsune Saga 《Fisheries Science》2008,74(4):822-829
ABSTRACT: To investigate inheritance of chloroplasts and mitochondria (organelles) in the marine red alga Porphyra yezoensis , cleaved amplified polymorphic sequence (CAPS) profiles of the two strains, TU-2 and KGJ, as parental gametophytes and 44 hybrid sporophytes (i.e. female of TU-2 and male of KGJ) were examined. A carbamyl phosphate synthase small subunit gene ( carA ) and ribosomal protein S11 gene ( rps11 )-small subunit ribosomal RNA gene ( rns ) spacer region were used as molecular markers for the chloroplast and mitochondrial DNAs, respectively. Thirty-eight of 44 (86.4%) conchocelis colonies showed maternal banding patterns, five (11.4%) colonies showed biparental bands and one (2.2%) colony showed paternal bands in CAPS analyses both with chloroplast and mitochondrial markers. These results suggest that organelles of P. yezoensis are inherited uniparentally from the female parent. 相似文献
34.
In order to change for the good flavor in green tea of middle or low grade,roast naked barley (miner ingredient) was added to it.To make tea having functional property,mixed roast naked barley-green tea with one medicinal herb (MH,miner ingredient).This study was performed to investigate the effect of drinking extracts of naked barley-MH-green tea (A group) and adlay-Angelica gigas Nakai-green tea (B group) on the body weights of rats,and volatile flavor components of best effective extract on weight reduction.Forty-eight male Sprague-Dawley rats divided into six groups were fed five different green tea extracts for 8 weeks.The result obtained in the experiment indicated that the change of body weights of rats was affected by A group,B group and others.A group showed highest reduction rate of body weights (36.40%).Reduction rate of body weights on the B group (10.10%) was much lower than A group (36.40%).Aroma compounds were extracted by the SDE method.The concentrated aroma extracts were analyzed and identified by GC and GC-MS.The main aroma components of the green tea blended with naked barley and MH were 12 pyrazines having roasty note,methyl butanals having sweet note,hexanal having briskness greenish note,and nerolidol and3-ionone having floral note. 相似文献
35.
Joanna Poluszyńska Elżbieta Jarosz-Krzemińska Edeltrauda Helios-Rybicka 《Water, air, and soil pollution》2017,228(8):305
The research comprised of studying the effect composting sewage sludge with sawdust and vermicomposting with earthworm Eisenia fetida has on the degradation of 16 polycyclic aromatic hydrocarbons (PAHs). Raw rural sewage sludge prior composting was more contaminated with PAHs than urban sewage sludge, in both cases exceeding EU cutoff limits of 6 mg/kg established for land application. Dibenzo[a,h]anthracene (DBahAnt), acenaphtylene (Acy) and indeno[1,2,3-c,d]pyrene (IPyr) were predominant in rural sewage sludge, whilst the urban sewage sludge contained the highest concentrations of benzo[b]fluoranthene (BbFl), benzo[k]fluoranthene (BkFl) and indeno[1,2,3-c,d]pyrene (IPyr). Thirty days of composting with sawdust has caused a significant reduction of 16 PAHs on average from 26.07 to 4.01 mg/kg (84.6%). During vermicomposting, total PAH concentration decreased on average from 15.5 to 2.37 mg/kg (84.7%). Vermicomposting caused full degradation of hydrocarbons containing 2 and 6 rings and significant reduction of PAHs with 3 aromatic rings (94.4%) as well as with 5 aromatic rings (83.2%). The lowest rate of degradation (64.4%) was observed for hydrocarbons with 4 aromatic rings such as fluoranthene, benzo(a)anthracene, chrysene and pyrene. On the other hand, the highest level of degradation was determined for PAHs with 2 rings (100%), 3 rings (88%) and 6 aromatic rings in the molecule (86.9%) after composting with sawdust. Acenaphthene and pyrene were found to be the most resistant to biodegradation during both composting methods. 相似文献
36.
Udomsil N Rodtong S Choi YJ Hua Y Yongsawatdigul J 《Journal of agricultural and food chemistry》2011,59(15):8401-8408
The potential of Tetragenococcus halophilus as a starter culture for flavor improvement in fish sauce fermentation was elucidated. Four strains of T. halophilus isolated from fish sauce mashes were inoculated to anchovy mixed with 25% NaCl with an approximate cell count of 10(6) CFU/mL. The α-amino content of 6-month-old fish sauce samples inoculated with T. halophilus was 780-784 mM. The addition of T. halophilus MRC10-1-3 and T. halophilus MCD10-5-10 resulted in a reduction of histamine (P < 0.05). Fish sauce inoculated with T. halophilus showed high contents of total amino acids with predominantly high glutamic acid. Major volatile compounds in fish sauce were 2-methylpropanal, 2-methylbutanal, 3-methylbutanal, and benzaldehyde. T. halophilus-inoculated fish sauce samples demonstrated the ability to reduce dimethyl disulfide, a compound contributing to a fecal note. The use of T. halophilus for fish sauce fermentation improves amino acid profiles and volatile compounds as well as reduces biogenic amine content of a fish sauce product. 相似文献
37.
A Laboratory Column Study on the Biodegradation of Toluene and Methyl tert–Butyl Ether: The Effect of Substrate Interactions 总被引:1,自引:0,他引:1
Chung Seung-Gun Kim Dong-Ju Lee Sang-Hyup Choi Jae-Woo 《Water, air, and soil pollution》2013,224(4):1-8
Soil vapor extraction (SVE) is one of the most effective remediation technologies for soil and groundwater contamination. Soil particles can be mobilized by air perturbation during SVE, resulting in the differentiation of porous media, which has not been well addressed. This paper developed a numerical method to study the flow pattern and quantify the change of porous media for the first time. Based on the mass equilibrium and Darcy’s law, a two-phase water–air flow model was constructed with integration of saturation, relative permeability, and capillary pressure during SVE. Relationship between porosity and saturation was deduced and coupled with the two-phase flow model for quantifying change of porous media in real time. Results reveal that both porosity and permeability increase sharply in the early stage of SVE then gradually to a quasi-steady state. These increases in vadose zone tapered off with distance from the SVE screen and the steady period occurred later as well. The influence radius of a single SVE well and the change degree in porosity and permeability of media were proportional to the extraction vacuum and the driving coefficient C, which is more sensitive than extraction vacuum according to the simulation results. Knowledge from this modeling exercise provides a useful tool to estimate the change of remediated zone and assess the environmental risk of remedial activities at real-world contamination sites. 相似文献
38.
Utilization of biochar impregnated with anaerobically digested slurry as slow‐release fertilizer
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We examined the possibility of an environment‐friendly slow‐release fertilizer (SRF) made of biochar impregnated by anaerobically digested slurry. The biochar materials were produced from three types of feedstocks (orange peel, residual wood, water‐treatment sludge) at different temperatures of 300°C, 500°C, and 700°C via pyrolysis. The release behaviors of the water‐soluble K+, Ca2+, and Mg2+ were similar for all impregnated biochars and the commercial SRF used. The water‐retention capacity was greatly improved by mixing the biochar‐SRF with the soil. The yield of lettuce was lower for the biochar‐SRF applications of 3.7 to 34.2 t ha–1 than for the commercial SRF application of 51.4 t ha–1. This might be due to excessive increase of soil pH for the biochar‐SRF application. Based on these results, the authors concluded that the biochar impregnated with nutrients could become an effective slow‐release K+ fertilizer. 相似文献
39.
The aim of the study was to examine effect of preharvest sprays of calcium (Ca) in the form of Ca-chloride (CaCl2), Ca-nitrate [Ca(NO3)2], or a mixture of Ca-formate, Ca-acetate, CaCl2, and Ca(NO3)2 on cracking and quality of ‘Schattenmorelle’ sour cherry fruit harvested mechanically. The experiment was conducted in 2008–2009 at a commercial orchard in central Poland. Mature trees grew on a coarse-textured soil poor in organic matter, at a spacing of 4.0 × 1.5 m. The spray treatments of Ca were performed at 7-day intervals, starting 28 days before harvest, at the rates of 5.0–5.6 kg Ca ha?1 per season. The trees sprayed with water were treated as the control. Fruit were harvested mechanically when peduncle-fruit detachment force dropped below 3 N. The results showed that preharvest Ca sprays caused no leaf damage. This measure did not affect yield, mean fruit weight, soluble solids concentration and titratable acidity of fruit, and weight loss of fruit during 24 h after harvest. Fruit sprayed with Ca had improved status of this nutrient, and were less liable to juicy leakage from the stem scar, rain-induced cracking, and preharvest decay caused by Glomerella cingulata. The above effects of Ca sprays did not depend on the tested material. It was concluded that preharvest sprays of Ca as CaCl2 and/or Ca(NO3)2 should be recommended in ‘Schattenmorelle’ sour cherry orchards to reduce fruit losses resulting from rain-induced cracking, leakage of juice, and the incidence of cherry bitter rot. 相似文献
40.
Bałczewski P Bachowska B Białas T Biczak R Wieczorek WM Balińska A 《Journal of agricultural and food chemistry》2007,55(5):1881-1892
The aim of this work was to synthesize chiral ionic liquids as chiral solvents for organic synthesis and to evaluate the phyto(eco)toxicity of the new products and starting N-alkylimidazoles and their potential environmental influence on soil and plants. Chiral ionic liquids containing anions such as Cl-, Br-, TsO-, PF6(-), NO3(-), CF3SO3(-), and (+)- and (-)-C6H5CH(OH)C(O)O- were synthesized using (-)-(1R)-6,6-dimethylbicyclo[3.1.1]hept-2-ene-2-ethyl [(-)-(1R)-nopyl] halides (X = Cl, Br) and tosylate in 62-100% yields. The chloride 7 and the nitrate 13 ionic liquids possessed a toxicity dependent on the applied concentration. The lowest concentration causing a distinct reduction in plant germination/growth was 100 mg/kg. Spring barley better tolerated the ionic liquids (200 mg/kg) than common radish (100 mg/kg). The nitrate liquid did not exhibit an inhibiting effect on the germination ability of seeds. The starting N-methylimidazole used in lower concentrations (1 and 10 mg/kg of soil dry weight) was not phytotoxic, in contrast to higher doses (>1000 mg/kg). 相似文献