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91.
Hans R. Gislerød 《Plant and Soil》1982,69(3):445-456
Summary The air content in three types of propagation media, Jiffy-7 and Jiffy-9 which are Sphagnum peat and Grodan which is rockwool,
were investigated when they were held at moisture tensions of 0,6 and 12 cm measured from the base of the media. At 0 cm tension
the air content (vol. %) was highest in Jiffy-9 and lowest in Jiffy-7. At 12 cm tension the air content was higher in Grodan
than in Jiffy-9 and Jiffy-7.
Oxygen diffusion coefficients (ODC) and oxygen diffusion rates (ODR) were measured at the different air contents. At air contents
below 20 vol. % ODC was about the same for Jiffy-9 and Grodan but at air contents above 20 vol.% it was larger for Jiffy-9
than for Grodan. The oxygen diffusion rate was measured at 0, 4 and 8 cm moisture tension. At all tensions it was approximately
20% higher in Jiffy-9 than in Grodan and Jiffy-7. The ODR in Jiffy-7 and Grodan were affected equally at the same tension,
although Grodan contained more air.
Report no 253 相似文献
92.
Elastosis, the significant increase of elastic tissue, was identified by histochemical methods in 45 (53.5%) cases of an unselected series of breast cancers. They were all invasive ductal carcinomas with or without tubular differentiation. The highest proportion of tumors with elastosis was found in the "scirrhous" type of carcinomas. Elastosis was preponderantly of the focal variety, periductal and perivenous. The affected ducts were of large calibre, containing a normal, benign hyperplastic or carcinomatous epithelium. There were not observed correlations with the grade of malignancy and the extent of axillary lymph node metastases. 相似文献
93.
A.J.v.d. Broek A.I.A. Broess M.J.v.d. Heuvel H.P. de Jongh J. Leemhuis K.H. Schonemann J. Smits J. de Visser N.P. van Vliet F.J. Zeelen 《Steroids》1977,30(4):481-510
Using the strategy based on the Hansch method which analyses effects of substituents on biological activity in terms of their hydrophobic, electronic and steric effects we selectively synthesised a series of 11β-substituted-17α-ethynyl-4-estren-17β-ols that combine ease of synthesis with good discrimination between these factors aiming at finding the compounds with optimum biological activity in that series. The compounds were tested quantitatively in the Clauberg test (rabbit) and the ovulation inhibition test (rat). The differences in biological activity could reasonably be correlated with two steric effects introduced by the 11β-substituent. These were a change in the overall shape of the 11β-substituent and the angular methyl group, and direct steric hindrance of the steroid-receptor protein binding. Some exceptions were found possibly due to metabolic conversion of these compounds to the corresponding 11β-substituted-17α-ethynyl-l,5,5(10)-estratriene-5, 17β-diols. 相似文献
94.
Mohamed Saïd Hifnawy Jacqueline Vaquette Thierry Sévenet Jean-Louis Pousset André Cavé 《Phytochemistry》1977,16(7):1035-1039
Stems and leaves of Myrtopsis macrocarpa, M. myrtoidea, M. novae-caledoniae and M. sellingii yielded terpenes, sterols, coumarins, alkaloids (furoquinolines and quinolones) and amides. A new quinolone (8-methoxy flindersine) occurs in Myrtopsis macrocarpa, a new amide (N-benzoyltryptamine) in M. myrtoidea, two new coumarins (myrsellin and myrsellinol) and a new dihydrofuroquinoline (myrtopsine) in M. sellingii. Structures of the new compounds are proposed from chemical and spectroscopic evidence. 相似文献
95.
Cell suspension cultures of parsley and soybean were incubated for 38 h with 14C-labeled benzo[a]pyrene; autoclaved cultures were used as controls. Metabolites were isolated by a sequential extraction procedure and further studied by chromatography or by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The soluble metabolites amounted to 1–2.2% in the case of parsley cells, and 19–28% in the case of soybean cells. These metabolites varied in polarity, some being soluble in organic solvent or aqueous buffer while other metabolite fractions were soluble only in hot aqueous sodium dodecylsulphate. In addition, a significant amount of an insoluble metabolite fraction was isolated from the culture fluid as well as the cellular material of soybean suspension cultures.Abbreviations BP
benzo[a]pyrene
- SDS
sodium dodecyl sulfate
- TCA
trichloroacetic acid 相似文献
96.
97.
Mhamed Sa?d El Kebbaj Norbert Latruffe Yves Gaudemer 《Biochemical and biophysical research communications》1982,108(1):42-50
In order to titrate and understand the role of arginyl residues of D-β-hydroxybutyrate dehydrogenase, arginyl specific reagents: butanedione, 1,2-cyclohexanedione and phenylglyoxal were incubated with three different forms of the enzyme; native enzyme (inner mitochondrial membrane bound), purified apoenzyme (phospholipid -free) and phospholipid-enzyme complex (reconstituted active form).After complete inactivation of the enzyme by [14C]-phenylglyoxal, the number of modified arginyl residues was different: one with the lipid-free apoenzyme and three with the phospholipid-enzyme complex, suggesting a conformational change of the enzyme triggered by the presence of phospholipids.After exhaustive chemical modification either of the apoenzyme or of the phospholipid-enzyme complex with [14C]-phenylglyoxal, four arginyl residues were titrated indicating that these residues are located in the hydrophilic part of the enzyme, not interacting with phospholipids.Reconstituted enzyme inactivated by butanedione could no longer bind a pseudosubstrate (succinate) which indicates that an arginyl residue is involved in the enzyme-substrate complex formation.The values of second order rate constants of D-β-hydroxybutyrate dehydrogenase inactivation by butanedione and 1,2-cyclohexanedione were unchanged with the three enzyme forms, suggesting that phospholipids are not involved in the substrate binding mechanism. 相似文献
98.
JiRí Moos Leopold Veselskýa Jana Pknicov Josef Drahord 《Molecular reproduction and development》1992,33(2):165-171
Sperm coating proteins of 16, 17, and 19 kDa have been purified from boar seminal plasma. The 17 kDa protein has been identified as an antigen recognized by monoclonal antibody ACR.3 and is thus identical to low molecular mass zona pellucida binding protein from boar spermatozoa (Moos et al., 1990). The 17 and 19 kDa proteins are glycosylated and tend to form hetero-complexes. The 17 kDa ACR.3 antigen is sequentially released from the sperm cell surface during capacitation and, after induction of the acrosome reaction, the 16 kDa form was also observed. Immunocytochemical studies on boar reproductive tissues have suggested that the seminal vesicle epithelium may be the source of these proteins. 相似文献
99.
100.
Amphipod crustaceans as an important component of zoobenthos of the shallow Antarctic sublittoral 总被引:2,自引:0,他引:2
Benthic quantitative samples were taken in 1988 in the soft bottom sublittoral of Admiralty Bay (King George Island, South Shetlands) using a Tvärminne-type bottom sampler and SCUBA-diving technique at 7 successive stations situated at depths from 4 to 30 m.Dominant animal groups in terms of abundance were Amphipoda, Polychaeta and Bivalvia, whereas in terms of biomass Echinoidea were also dominant. Amphipod crustaceans clearly dominated the zoobenthos at depths from 10 to 25 m (the numerical share surpaising 60%) with maximal abundance of abt. 17 000 ind m–2; in terms of biomass at specific depths amphipods occupied the 1st, 2nd or 3rd place with maximal biomass of abt. 100 g m–2 where the maximal total biomass of zoobenthos reached 260 g m–2 (10 m).Amphipoda were the most diversified group with some 35 taxa belonging to 14 families. Most species belonged to Eusiridae s.l. and Lysianassidae s.l. Dominant forms were Pontogeneiella brevicornis, Prostebbingia gracilis, Schraderia gracilis, Hippomedon kergueleni, Orchomenella cf. ultima, Cardenio paurodactylus and Paraphoxus rotundifrons. 相似文献