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排序方式: 共有178条查询结果,搜索用时 109 毫秒
111.
Delphine Manka'abusi Dsir J. P. Lompo Christoph Steiner Mariko Ingold Edmund Kyei Akoto-Danso Steffen Werner Volker Hring George Nyarko Bernd Marschner Andreas Buerkert 《植物养料与土壤学杂志》2020,183(4):500-516
To quantify carbon (C) and nitrogen (N) losses in soils of West African urban and peri‐urban agriculture (UPA) we measured fluxes of CO2‐C, N2O‐N, and NH3‐N from irrigated fields in Ouagadougou, Burkina Faso, and Tamale, Ghana, under different fertilization and (waste‐)water regimes. Compared with the unamended control, application of fertilizers increased average cumulative CO2‐C emissions during eight cropping cycles in Ouagadougou by 103% and during seven cropping cycles in Tamale by 42%. Calculated total emissions measured across all cropping cycles reached 14 t C ha?1 in Ouagadougou, accounting for 73% of the C applied as organic fertilizer over a period of two years at this site, and 9 t C ha?1 in Tamale. Compared with unamended control plots, fertilizer application increased N2O‐N emissions in Ouagadougou during different cropping cycles, ranging from 37 to 360%, while average NH3‐N losses increased by 670%. Fertilizer application had no significant effects on N2O‐N losses in Tamale. While wastewater irrigation did not significantly enhance CO2‐C emissions in Ouagadougou, average CO2‐C emissions in Tamale were 71% (1.6 t C ha?1) higher on wastewater plots compared with those of the control (0.9 t C ha?1). However, no significant effects of wastewater on N2O‐N and NH3‐N emissions were observed at either location. Although biochar did not affect N2O‐N and NH3‐N losses, the addition of biochar could contribute to reducing CO2‐C emissions from urban garden soils. When related to crop production, CO2‐C emissions were higher on control than on fertilized plots, but this was not the case for absolute CO2‐C emissions. 相似文献
112.
In vitro culture conditions using chemically defined media for in vitro matured and intracytoplasmically inseminated porcine oocytes 总被引:1,自引:0,他引:1
The present study investigated in vitro culture methods [droplet and Well of the Well (WOW)] using semi-defined and defined media [modified porcine zygote medium (mPZM)] and the additional effects of insulin on in vitro matured and intracytoplasmically inseminated porcine oocytes. In Experiment 1, in vitro matured and intracytoplasmically inseminated porcine oocytes were cultured for 6 days in the following four groups: 1) mPZM-3 (containing bovine serum albumin) + droplet (30 mul), 2) mPZM-3 + WOW, 3) mPZM-4 (containing polyvinyl alcohol) + droplet, and 4) mPZM-4+ WOW. The culture media (mPZM-3 and mPZM-4) and methods (droplet and WOW) did not significantly affect the cleavage rate, but the blastocyst rate of the oocytes cultured in mPZM-3 was significantly (P<0.01) higher than that of mPZM-4 (20.1 and 9.4%, respectively). The blastocyst rates as percentages of the cleaved oocytes (51.8 and 16.9%) and the hatched blastocyst rate as percentages of the number of blastocysts (12.3 and 2.2%) were also significantly (P<0.01) higher in mPZM-3 compared with those in mPZM-4. There was significant interaction (P<0.05) between the two main factors; the effects of the culture media and methods on the rate of hatched blasyocysts as percentages of the blastocysts produced and, the hatched blastocyst rate (20.3%) as percentages of the number of blastocysts produced in mPZM-3 were significantly (P<0.05) higher than in the other groups. In Experiment 2, the additional effects of insulin (100 ng/ml) in mPZM-3 and mPZM-4 media was investigated in the WOW culture system. Insulin addition did not improve cleavage, blastocyst formation, or the number of cells in blastocysts. However, as in Experiment 1, mPZM-3 resulted in a significantly higher blastocyst rate as percentages of the cleaved oocytes than mPZM-4 (33.9 and 18.4%). These results indicate that a chemically defined medium (mPZM-4) needs to be improved to provide more suitable culture conditions for in vitro development of in vitro matured and intracytoplasmically inseminated porcine oocytes. However, the WOW system may be a useful IVC method for blastocyst development of in vitro matured porcine oocytes following ICSI when a semi-defined medium (mPZM-3) is used. 相似文献
113.
K Yasuno H Sakashita S Araki R Kobayashi Y Sakurada M Shirota J Kamiie K Shirota 《Journal of toxicologic pathology》2012,25(2):175-178
This report describes a spontaneous hybrid cyst in a Sprague-Dawley (SD) rat. A 52-week-old, male SD rat had a cutaneous cyst on the left mystacial pad. Histologically, the cyst wall showed infundibular differentiation with keratohyalin granules in the granular layer and matrical differentiation comprising basaloid epithelial cells with trichohyalin granules. The cyst cavity was filled with lamellar, flaky keratin and aggregates of shadow cells. Immunohistochemically, the infundibular-type epithelium was positive for cytokeratin (CK) AE1/AE3, CK KL1 and CK14 but negative for CK15, whereas the matrical-type epithelium was negative for all four CK isoforms examined. These immunohistochemical properties of the infundibular- and matrical-type epithelia were similar to those of the infundibulum and inferior segment of normal hair follicles, respectively. Based on these findings, the cyst was diagnosed as a hybrid cyst, comprising more than one type of cyst arising from various parts of the pilosebaceous unit. 相似文献
114.
Manao Ozawa Michiko Kawanishi Mariko Uchiyama Daisuke Mitsuya Hitoshi Abo Ryoji Koike Mayumi Kijima 《Journal of veterinary diagnostic investigation》2021,33(4):744
We analyzed the correlation between minimum inhibitory concentrations (MICs) of antimicrobials used in humans and those used in animals to enable comparison of antimicrobial susceptibility between Escherichia coli isolated from humans and those from animals. We compared the following pairs of MIC data: piperacillin (PIPC) to ampicillin (ABPC), amikacin (AMK) to kanamycin (KM), minocycline (MINO) to oxytetracycline (OTC), and levofloxacin (LVFX) to enrofloxacin (ERFX) using 103 isolates of E. coli from healthy livestock (cattle, pigs, broiler chickens, and layer chickens). Kappa analysis of the agreement for resistance and susceptibility between PIPC and ABPC, AMK and KM, MINO and OTC, and LVFX and ERFX showed almost perfect (κ = 0.81), slight (κ = 0.12), fair (κ = 0.37), and moderate (κ = 0.46) agreement, respectively. Within the antimicrobial pairs, all isolates resistant to the human antimicrobial were also resistant to the veterinary antimicrobial. However, there was less agreement within the pairs for those isolates that were sensitive to the human antimicrobial. The percentage agreement for susceptibility, defined as the percentage of isolates sensitive to both antimicrobials compared with isolates sensitive to both antimicrobials, as well as those sensitive only to the human antimicrobial, was 89.9%, 87.3%, 64.0%, and 89.9% for PIPC and ABPC, AMK and KM, MINO and OTC, and LVFX and ERFX, respectively. Our results suggest that the possibility of missing the resistance for antimicrobials used in human medicine by examining MICs for the equivalent antimicrobials used in veterinary medicine is low. 相似文献
115.
Ko Tahara Mariko Norisada Takeshi Tange Hisayoshi Yagi Katsumi Kojima 《Soil Science and Plant Nutrition》2005,51(3):397-403
To investigate the effects of ectomycorrhizal association on the aluminum (Al) tolerance of Pinus densiflora Sieb. & Zucc., seedlings with or without ectomycorrhizal association with the fungus Pisolithus tinctorius (Pers.) Coker & Couch were exposed to 1 mM Al. Association with P. tinctorius alleviated Al-induced inhibition of root elongation and biomass growth in the mycorrhizal seedlings. Secretion of malate and citrate, both low-molecular-weight organic acids that could detoxify Al by the formation of stable complexes, was investigated in P. tinctorius mycelia and in pine roots with and without P. tinctorius association. Citrate secretion from the P. tinctorius mycelia in vitro was stimulated by Al. Citrate secretion from the roots of the ectomycorrhizal seedlings was also stimulated by Al, but was not detected in the non-mycorrhizal seedlings. These results suggest that citrate secreted from the roots of the ectomycorrhizal seedlings was produced in the hyphae of P. tinctorius. Citrate secretion may play a role in enhancing the Al tolerance of host seedlings. 相似文献
116.
117.
Kato T Saito N Kashimura K Shinohara M Kurahashi T Taniguchi K 《Journal of agricultural and food chemistry》2002,50(22):6307-6312
On the basis of our findings that the germination of intact wheat seeds (with husks) belonging to dormancy varieties was restrained as compared with that of the dehusked seeds (grains), the germination inhibitors in the husks were explored. The water-soluble extracts from the husks were separated by the aid of inhibition assay experiments, resulting in the characterization of 2-phenylethyl alcohol 1, 4-vinylphenol 2 and its 2-methoxy derivative 3, and dihydroactinidiolide 4, all of which showed clear inhibition of germination at 500 ppm in aqueous solution. The related compounds 1-phenylethyl alcohol 5 and tetrahydroactinidiolide 6 were as active as 1 and 4, while no noticeable difference in activity was detected among both enantiomers and the DL-form of compounds 4-6. Clear synergistic relations were observed between 4 and 1 and also 4 and 3. Since the present inhibitors have been isolated from various kinds of seed plants, they may be responsible for the general germination inhibition in the seed plants. 相似文献
118.
Hiromi?TanabeEmail author Takashi?Nakano Manami?Mimura Yoshiko?Abe Shigeru?Mariko 《Journal of Forest Research》2003,8(4):247-252
We assessed the above- and below-ground biomass and net primary production (NPP) in a mature (85-year-old) Pinus densiflora forest established on a lava surface of Mt. Fuji in central Japan. The nitrogen (N) concentration of the forest soil was low (1.25%), and the mean soil carbon/nitrogen (C/N) ratio was 34.2; therefore, both plants and microorganisms would compete for N in our research forest. The total biomass was 192.62Mgha–1, of which 67.28% was in the stems and 25.71% was in the roots. The fine-root biomass was 1.12% of the total biomass. The total NPP of the forest reached 11.89Mgha–1 year–1, which fell within the values reported for other cool temperate P. densiflora forests established on non-volcanic-related substrata. The below-ground production was about 39% of the total NPP; the value was relatively small under the conditions of low total N concentration and high soil C/N ratio. Our study suggested that P. densiflora could recruit and grow on geologically new substrata without increasing the allocation of its annual carbon budget to below-ground organs (i.e., roots). 相似文献
119.
A new prenylated flavone, named artoindonesianin P (1), was isolated from the tree bark of Artocarpus lanceifolius, together with three known related compounds, artobiloxanthone (2), cycloartobiloxanthone (3) and artonol B (4). The structure of artoindonesianin P 1 was determined on the basis of spectral evidence (MS, 1H and 13C NMR) and by comparison with known related compounds. Compounds 1-4 exhibited significant cytotoxicity against murine P388 leukemia cells. 相似文献
120.
Aminah NS Achmad SA Aimi N Ghisalberti EL Hakim EH Kitajima M Syah YM Takayama H 《Fitoterapia》2002,73(6):501-507
A new C-glucoside of epsilon-viniferin, named diptoindonesin A (1), was isolated from the ethyl acetate extract of the tree bark of Shorea seminis, together with the known stilbene oligomers (-)-ampelopsin A (2), (-)-alpha-viniferin (3), and (-)-hopeaphenol (4). The structure of 1 was determined from spectroscopic evidence. 相似文献