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311.
M. C. Gil M. C. DE LA Rosa M. A. Mosso M. L. Garcia Arribas 《Journal of applied microbiology》1986,61(4):347-356
Numerical taxonomy procedures were used to study 118 strains of Bacillus isolated from non-sterile drugs prepared for oral administration. Similarities between pairs of strains were calculated by the simple matching coefficient of Sokal and Michener (SSM ). Each strain was tested for 60 unit characters and three clusters were defined. The strains in each cluster presented a similarity level of at least 60%. Cluster A comprised the strains identified as Bacillus cereus (SSM = 93·13%), cluster B contained three subgroups corresponding to the species B. pumilus, B. subtilis and B. licheniformis (SSM = 84·35%) and cluster C also included three subgroups that belonged to the species B. firmus, B. lentus and B. badius (SSM = 80·14%). The most discriminating tests were selected to differentiate the clusters from the subgroups. The feature with the highest discriminating power between clusters A and B was the lack of acid production from arabinose and mannitol. The Voges-Proskauer, methyl red tests and sensitivity to polymyxin B clearly distinguished cluster A from C. The Voges-Proskauer test and acid production from arabinose were the best to differentiate between B and C. Bacillus pumilus and B. subtilis differed in starch hydrolysis and B. licheniformis in growing anaerobically. To discriminate B. firmus from B. lentus the most important tests were the acid production from glucose and sucrose; intermediate strains were found. Bacillus badius was differentiated from B. firmus by 10 tests, and from B. lentus by the production of urease. 相似文献
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314.
Synaptosome Antisera affect Permeability of Synaptosomal Membranes <Emphasis Type="Italic">in vitro</Emphasis> 总被引:2,自引:0,他引:2
ANTISERA against specific regions of the brain can specifically influence the electrical activity of those regions1,2. It is possible that these immunological techniques may be used to determine the role of specific chemical components in brain function. 相似文献
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The differences in K+ uptake of different segments of excised roots of two thermophilic plants (rice, Oryza sativa L. cv. Dunghan Shali and cucumber, Cucumis sativus L. cv. Csemege Fürtös) and a non-thermophilic plant (wheat, Triticum aestivum L. cv. Aurora) were investigated in the presence and absence of Ca2+, at 0 and 25°C, using radiotracer K+(86Rb+) technique. The K+ uptake exhibited different temperature- and Ca2+-dependent distributions along the root axis for the different species studied. In the case of rice and cucumber an extraordinarily large K+ uptake occurred in the apical root portion at 0°C if Ca2+ was omitted. The presence of Ca2+ diminished this anomaly. For wheat normal K+ uptake patterns were observed under similar conditions. At 25°C Ca2+-stimulated K+ uptake may appear in each root segment, depending upon species and composition of the uptake solution. The results indicate that there may be considerable differences in the compositions of the cell walls and membranes of root cells of thermophilic and non-thermophilic plants, and in their ion-exchange properties, especially in the apical region. 相似文献
317.
The effects of Ca2+ and temperature on the K+ contents of root segments of wheat (Triticum aestivum L. cv. Aurora), rice (Oryza sativa L. cv. Dunghan Shali) and cucumber (Cucumis sativus L. cv. Csemege Fürtös) were investigated with special regard to the low-temperature anomaly of the K+ uptake of thermophilic plants. The anomaly occurred in those root segments where the K+ contents turned out to be highest. The K+ contents of the apical root sections of thermophilic species responded in general to Ca2+ in more pronounced ways than those of wheat, at both 0 and 25°C. The concerted actions of a purely physical process with negative temperature coefficient and of the special thermotropic properties of the membranes are suggested to be responsible for the low-temperature anomaly. A strict discrimination between the Viets-effect on the content (classical Viets-effect) and on the uptake is proposed. The classical Viets-effect seems to be related to alterations in both active transport and exchange processes. 相似文献
318.
The neurohypophysial hormone, arginine vasotocin, is depletedfrom the hypothalamus, and rises in concentration in the bloodduring oviposition in hens. The contractile responses of isolatedoviducts from birds, reptiles and amphibians are more sensitiveto arginine vasotocin than to oxytocin or mesotocin. This evidenceclearly indicates that arginine vasotocin is involved in parturitionor oviposition in nonmammalian tetrapods. Evidence for a physiologicalrole for specific neurohypophysial hormones in the regulationof oviductor in some cases ovarian contractilityin fishes is unclear and occasionally contradictory. However,it appears unlikely that arginine vasotocin is involved in thefish species that have been investigated. It is evident that,much like the neurohypophysial hormones, the neurohypophysialhormone receptors of the vertebrate myometrium have undergoneevolutionary change. 相似文献
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The in vivo absorbance spectrum of the inner seed coat of Cyclanthera explodens Naud. showed a main peak in the red region at 671 nm and a weak shoulder at about 640 nm. The pigments were extracted with acetone. separated by paper chromatography and analysed spectrophotometrically. The only detectable pigment was protochlorophyll. The in vivo fluorsecence emission spectra had two main peaks, one at 632 and one at 691 nm. The relation between the two peaks was changed when the exvcitation wavelength was altered from 440 to 460 nm. Excitation at 420 nm gave an additional fluorescence emission peak at 595 nm. These data indicate the presence of at least three forms of protochlorophyll in the Cyclantera seed coat. The spectrum of circular dichroism had a very intence and characteristic signal in the red region with a negative asymmetrical Cotton effect (664 (+), 669 (0) and 687 (?) nm). This indicates that at least one of the protochlorophyll forms is present in a more or less crystalline form. 相似文献