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81.
Ferdinand Bohlmann Christa Zdero Robert M. King Harold Robinson 《Phytochemistry》1980,19(12):2663-2668
The investigation of three Eremanthus species afforded, in addition to known compounds, several new sesquiterpenelactones, a cumambrin B isobutyrate, four lactones related to the eremantholides, two to zexbrevin and one to goyazensolide. Furthermore, a new coniferyl alcohol derivative was isolated. The overall picture of the genus is very uniform. The occurrence of eremanthine and germacranolides with a furanone ring seems to be especially typical. 相似文献
82.
83.
K.G. Blass R.L. Briand D.S. Ng S. Harold 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1980,182(3):311-316
A miniature two-dimensional thin-layer chromatographic procedure employing silica gel impregnated glass-microfiber chromatography sheets (commercial product, ITLC-type SG sheets) has been developed for the separation of lecithin (L) and sphingomyelin (S) from a standard lipid mixture containing L, S, lysolecithin, phosphatidyl inositol (PI), phosphatidyl serine (PS), phosphatidyl ethanolamine, phosphatidyl glycerol, and diphosphatidyl glycerol. The newly developed procedure eliminates possible interference from PI and PS. Complete separation of L and S was easily achieved with chromatographic solvent migration times of approximately 3 and 2 min for the first and second dimensions, respectively. The lipids were visualized by charring and fluorescent staining techniques. The procedure has been adapted for the separation of L and S from amniotic fluid samples. 相似文献
84.
85.
A simple plate assay for hyaluronidase activity in biological samples is described. Hyaluronic acid is incorporated into agarose gels and the enzyme is allowed to diffuse from punched wells. The undigested hyaluronic acid is then precipitated with cetylpyridinium chloride and the diameters of the clear circles are proportional to the logarithm of the enzyme concentration applied to the well. The assay was utilized to examine commercially available hymenoptera venoms, manufactured for use in allergy diagnosis and treatment, for their content of hyaluronidase as a measure of lot-to-lot consistency. The assay permits the analyses of a large number of samples with good reproducibility, without the need for any special instrumentation. Based on the quantity of purified hyaluronidase reported in honey bee venom (T. P. King, A. K. Sobotka, L. Kochoumian, and L. M. Lichtenstein, 1976, Arch. Biochem. Biophys.172, 661–671) we estimate that the assay should detect 70 ng/ml of purified honey bee venom hyaluronidase. 相似文献
86.
Roxanne Deslauriers Harold C. Jarrell R.Andrew Byrd Ian C.P. Smith 《Biochemical and biophysical research communications》1980,95(3):1211-1217
studies of have shown that encysting cells release polyphosphate into the encystment medium. Mature cysts contain low levels of polyphosphate, as do vegetative cells. Young cysts (7 days) show detectable levels of nucleotide diphosphates and triphosphate similar to those observed in vegetative cells. Mature cysts (90 days) show only excreted polyphosphate as well as a component which has a chemical shift of a phosphodiester. The inorganic phosphate peak in the cyst shows that the cyst milieu is liquid-like and that the intracellular environment maintains a pH between 6 and 7.5 in the presence of extracellular values from 4 to 9. 相似文献
87.
88.
89.
Harold P. Klein 《Origins of life and evolution of the biosphere》1976,7(3):273-279
The Viking biological investigation will be conducted in the face of a number of constraints. Problems are created because of the inherent engineering of the instrument, communication constraints and other factors. 相似文献
90.
Harold L. McMullen John R. Sauer Robert L. Burton 《Journal of insect physiology》1976,22(9):1281-1285
The mouth is confirmed as the site of water vapor uptake in the lone star tick, Amblyomma americanum. It was shown that the level of chloride (36Cl) increased in the mouthparts of desiccated ticks. The highest levels of 36Cl were found in the mouthparts, salivary glands, and gut tissue during rehydration. It is suggested that ions are secreted by the salivary glands into the mouth where water is picked up hygroscopically by the secretion. It is further suggested that the water and ions are then swallowed and absorbed from the lumen of the gut. 相似文献