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861.
A ten-step synthesis of lunularic acid, starting from phenyl β-chloropropionate is described. Detailed spectroscopic data are given for lunularic 相似文献
862.
R.K. Campbell T.M. Perring G.L. Barnes R.D. Eikenbary C.R. Gentry 《Journal of invertebrate pathology》1978,31(3):289-295
Natural isolates of two entomogenous fungi, Beauveria bassiana and Metarrhizium anisopliae, were cultured in liquid culture media containing 24 amino acids and KNO3 to determine their effect on growth and sporulation. In addition, the growth and medium pH changes for each isolate grown on an asparagine-containing medium were compared. Tryptophan and alanine were most effective for growth and sporulation of B. bassiana, although glutamine and KNO3 also produced large numbers of regularly shaped spores. Tryptophan, glutamic acid, and histidine were all well utilized for both growth and sporulation of M. anisopliae. Nitrogen sources containing sulfur were poorly utilized for sporulation by M. anisopliae. In general, B. bassiana produces greater mycelial mass and much larger numbers of spores than M. anisopliae. Both fungi attained nearly the same growth maximum on asparagine medium though B. bassiana exhibited an initially more rapid growth rate. In both fungi this rapid growth phase was accompanied by a decline in medium pH followed by a rise in pH during the decline phase of growth. 相似文献
863.
The heated biuret-Folin method for determining protein consistently measures 90% of the total nitrogen of filtered algae samples as protein-N without the need of mechanical disruption as long as the heating period in biuret is 100 min at 100 C. Data indicate this protein assay measures total protein on all species tried and for naturally occurring mixtures of species plus detritus. Dilute algal suspensions with as little as 0.05 μg-atom particulate protein N.liter -1 can he concentrated by fltration on glass fiber filters to 1.0 μg-atom particulate protein-N per filter, the optimal amount of sample for a 5 ml volume of biuret. The filtered algae samples can be stored for several weeks frozen before assaying, if necessary. 相似文献
864.
Laminaria saccharina Lamour. sporophytes were grown in enriched and synthetic media through a range of nitrate concentrations, There was an approximately linear relationship between growth and nutrient concentration up to 10 μ substrate concentration. The half-saturation constant (K2) was ca. 1.4 μ NO3-. The internal levels of NO3- increased at substrate concentrations above 10 μM b>3- and reached levels several thousand times higher than the surrounding medium. Thus there is evidence for luxury consumption of NOsb>3-. The chlorophyll content and photosynthetic capacities of plants also increased with increasing external NO3- The ecological implications of this work are considered. 相似文献
865.
ERIC A. KWEI 《Zoological Journal of the Linnean Society》1978,64(2):151-175
Blue crabs Callinectes latimanus (Rath.) trapped from two lagoons were sexed, measured and weighed. The eggs of the mature females were counted to determine fecundity, and the spermatophores of the males were counted to determine the size of sexual maturity. Sizes at maturity of both male and female crabs were determined. The methods employed and the results are discussed. 相似文献
866.
Jan M.C. Geuns 《Phytochemistry》1978,17(1):1-14
The occurrence of steroid hormones in plants is briefly reviewed. Their effects on plant growth, development and flowering are also considered. 相似文献
867.
Rajinder S. Dhindsa 《Planta》1978,141(3):269-272
The effects of 5-bromo-2-deoxyuridine (BUdR, thymidine analogue), AMO-1618 (2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride), a growth retardant, and p-chlorophenoxyisobutyric acid (PCIB, an antiauxin) on growth (dry weight increase) and fiber development in unfertilized cotton (Gossypium hirsutum L.) ovules grown in vitro have been studied. BUdR (5 M) causes about 70% inhibition of fiber production, with little effect on ovule growth, if applied during the first 6 d of culture in the presence of GA3 and IAA. AMO-1618, when used with GA3 alone, causes only a small reduction in both dry weight and fiber production, but when used with IAA alone reduces both fiber production and dry weight, the effect on the latter being predominant. In the presence of both IAA and GA3, AMO-1618 causes a small decrease in fiber production but a major decrease in dry weight. PCIB completely inhibits fiber growth but has little effect on dry weight, especially when GA3 is present. These results indicate that GA3 mainly promotes ovule growth while IAA is largerly responsible for fiber growth.Abbreviations AMO-1618
2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride
- BUdR
5-bromo-2-deoxyuridine
- GA3
gibberellic acid
- IAA
indole-3-acetic acid
- PCIB
p-chlorophenoxyisobutyric acid
- TFU
total fiber units 相似文献
868.
Aharon Aharonov Dennis S. Passovoy Harvey R. Herschman 《Journal of cellular biochemistry》1978,9(1):41-45
Swiss 3T3 and C3H-M2 cells have a greater mitogenic response to epidermal growth factor (EGF) than do C3H-10T1/2 cells. The latter cell line, however, has a number of EGF receptors per cell intermediate between the two cell lines that have a more vigorous response to EGF. Scatchard analysis of binding data indicate that all three cell lines have one class of EGF receptor, with indistinguishable affinity for the ligand. When exposed to 10-nM EGF all three cell lines “down-regulate” their EGF receptors with the same time course, and to the same precentage of initial receptors. 相似文献
869.
Harvey R. Herschman Dennis S. Passovoy Rebecca M. Pruss Aharon Aharonov 《Journal of cellular biochemistry》1978,8(3):263-268
The growth-promoting activities of fetal bovine serum, cortisol, phorbol myristate acetate, prostaglandin F2α, insulin, epidermal growth factor, and fibroblast growth factor were evaluated on four murine embryo cell lines (Swiss 3T3, Balb 3T3, M2, and C3H10T1/2). Each cell had an unique response spectrum to this collection of reported mitogens. Phorbol myristate acetate and prostaglandin F2α were active only on selected cell lines; cortisol was inactive on all four lines. Serum, epidermal growth factor, and fibroblast growth factor were able to stimulate cell division in all four lines, albeit to varying degrees for the different target cells. 相似文献
870.
Differences in growth response to hydrocortisone and ascorbic acid by human diploid fibroblasts 总被引:2,自引:0,他引:2
David W. Rowe Barbra J. Starman Wilfred Y. Fujimoto Robert H. Williams 《In vitro cellular & developmental biology. Plant》1977,13(12):824-830
Summary The effects of hydrocortisone and ascorbic acid on growth parameters were measured in human diploid skin fibroblasts from
fetal and adult donors. In the presence of culture medium containing 10% fetal bovine serum, 0.3 μM hydrocortisone produced
a 20% increase in the population growth rate and a 50 to 70% increase in the confluent density of fibroblasts from adult donors.
Daily addition of 28 μM ascorbic acid also stimulated the population growth rate and cell density at confluency. The effects
of hydrocortisone and ascorbic acid on the final cell density were additive. The action of hydrocortisone was restricted to
cells in log-phase growth, whereas ascorbic acid affected cells in both the log and the postconfluent phases of the growth
cycle. In fibroblasts from fetal donors, ascorbic acid was stimulative but hydrocortisone was not. The data suggest that whereas
both compounds stimulate cell growth in an additive manner, they do so by different cellular mechanisms.
This investigation was supported in part by USPHS Grants AM 02456, AM 05020 and AM 15312, and by the Kroc Foundation, No.
UW 63-2986. Dr. Rowe is a fellow of the Helen Hay Whitney Foundation. Dr. Fujimoto is a recipient of a Research Career Development
Award, AM 47142, from NIAMDD. 相似文献