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21.
Hisanori Konishi Muhammad Golam Morshed Hisaji Akitomi Teruko Nakazawa 《Microbiology and immunology》1993,37(3):229-232
Borrelia duttonii strain 406 K, a causative agent of relapsing fever, could not be cultivated in vitro in currently available media for borreliae. We have developed an in vitro cultivation system by using SflEp cell cultures. The average increases of the number of borreliae, when inoculated with 1.0 × 105 organisms per ml from infected mice, were 23-fold and 150-fold in the primary culture and the 3rd subculture, respectively. Even a single borrelia could propagate in this cultivation system. This system will be useful for immunological and physiological studies on uncultivable Borrelia strains. 相似文献
22.
Various laboratory techniques have been utilized worldwide for measuring lead-210 in sub-recent deposits through its grand-daughter product polonium-210. Isotope dilution alpha spectrometry proved a suitable tool for absolute determination of lead-210 for the dating of aquatic deposits. Moreover, isotope dilution alpha spectrometry along with speciation experiments can be used to resolve depositional anomalies arising from supported lead-210/Ra-226 disequilibrium levels and unsupported lead-210 mobile fractions. Isotope dilution alpha spectrometry of sub-recent sediment and peat deposits has been critically evaluated for more than ten years. Our results show that type, size and composition of deposits analyzed as well as radiochemical procedures used, together with alpha counting techniques, are important factors influencing lead-210 determinations and tailing corrections using its granddaughter product polonium-210. Optimization of these parameters is of prime importance to achieve economic and accurate analyses, especially at low lead-210 concentrations and small sample sizes. 相似文献
23.
24.
Jorge M. Canhoto Maria Ludovina S. Guimarães Gil S. Cruz 《Plant Cell, Tissue and Organ Culture》1990,21(2):171-177
Pollen of Iochroma warscewiczii Regel (Solanaceae) produced embryogenic calli or embryos inside anthers cultured on Nitsch & Nitsch medium. Two distinct pathways could be recognized in this process, one involving mainly the vegetative cell, and the second starting with two equal cells in the pollen grains.In all media tested, androgenesis initiation was highest when anthers contained pollen at the first mitosis, or close to it, at inoculation. High sucrose (7%) and calcium (11.3 mM) concentrations were found to be highly desirable for the induction of androgenesis in this species. Addition of benzylaminopurine (0.5 mg l–1) to the culture medium seems to slightly improve callus or embryo production. When all three factors were present at optimal concentrations as much as 13.9% of inoculated anthers were found to be embryogenic.Plantlet development from pollen embryos required lower sucrose (3%) and a combination of 0.1 mg l–1 benzylaminopurine and 0.5 mg l–1 gibberellic acid in the culture medium. Cytological analysis of 55 regenerated plantlets showed that about 49% were haploids, but diploid (ca. 49%) and triploid (ca. 2%) plants were also obtained. 相似文献
25.
Elicitor-induced hydroxycinnamoyl-CoA:tyramine hydroxycinnamoyltransferase in plant cell suspension cultures 总被引:4,自引:0,他引:4
Treatment of Nicotiana glutinosa L. cell suspension cultures with chitosan results in the co-induction of phenylalanine ammonia lyase, 4-eoumarate:CoA ligase, tyrosine decarboxylase and tyramine hydroxycinnamoyltransferase, all involved in the biosynthesis of hydroxycinnamoyltyramines. The highest enzyme activities were observed around 12 h after addition of 0.8 to 1 mg chitosan per g fresh weight of cells. No hydroxycinnamoyltyramines could be detected by TLC or HPLC of extracts made from non-treated or elicited cells. [14 C]-Tyramine was incorporated into insoluble polymeric material at a higher rate in elicitor-treated than in non-treated cells of N. glutinosa. Tyramine hydroxycinnamoyltransferase could be induced in suspension cultured cells of Eschscholtzia califortnca Cham, but not in cells of Phaseolus vulgaris L. or Catharanthus roseus (L.) G. Don by addition of a yeast elicitor to the growth medium. 相似文献
26.
The effect of water stress on the vacuole-extravacuole compartmentation of proline in potato cell suspension cultures 总被引:1,自引:0,他引:1
Solute compartmentation in cells is an important component of metabolic regulation. There is only little information on how stress treatment of cells effects this component. Therefore, the effect of water stress [10% (w/v) PEG 6000] on the vacuolar-extravacuolar proline compartmentation was studied in a cell suspension culture of Svlanum tuberosum L, cv, HH258, In non-stressed cells 34% of the total cellular proline was located in the vacuole. After 20 h of water stress the proline pool of the cells was increased 4-6 fold and only t6% of it was found in the vacuole. A negative correlation between the total cellular proline content and its percentage in the vacuole was observed, irrespective of the culture method (stress or non-stress culture). The stress-induced changes in proline compartmentation are discussed. 相似文献
27.
28.
《Bioorganic & medicinal chemistry letters》2020,30(16):127289
The present research project details synthesis of new hybrid methanofullerenes based on acetylene and triazole esters of malonic acid containing 5Z,9Z-dienoic acids and fullerene C60 under Bingel-Hirsch conditions, including study of the cytotoxic activity with respect to Jurkat, K562, U937 and HL60 tumor cell lines. Hybrid methanofullerenes containing acetylenic fragments, unlike triazole substituents, were found to exhibit higher cytotoxicity, but are characterized by lower selectivity of action in relation to healthy cells. 相似文献
29.
Laura Santagostini Elisabetta Caporali Claudia Giuliani Martina Bottoni Roberta Ascrizzi Silvia R. Araneo 《Plant biosystems》2020,154(3):316-325
AbstractSeveral aroma hops (Humulus lupulus L.) were recently introduced in Northern Italy as a small-scale production of excellence. In this preliminary study, the American cultivar Cascade was investigated in a combined morphological and phytochemical survey. Morphological investigation on trichome structure, density and distribution was performed by scanning electron microscopy and light microscopy. Essential oil composition, α/β-acid and polyphenol profiles over 3 years were determined by GC-MS and HPLC analyses. Two types of non-glandular (simple and cystolithic) and glandular (peltate and bulbous) trichomes were observed on leaves and female inflorescences. The peltate trichomes resulted as the main sites of terpene production and accumulation. The essential oil profiles showed myrcene, β-caryophyllene, (E)-β-farnesene and humulene epoxide II as the dominant compounds over the three collection times, although with different relative abundances. The presence of two exclusive compounds, γ-muurolene and trans-γ-cadinene, characterized the investigated cv. Cascade, potentially enhancing herbal, woody and spicy aroma traits of this cultivation in Northern Italy. The bitter acid composition showed quantitative values consistent with literature data only for the second and third monitoring year. Qualitative differences in polyphenol content were also recorded, for the presence of quercetin-3-O-malonylglucoside and kaempferol-3-O-rutinoside, which may characterize this peculiar Italian cultivation. 相似文献
30.
《Saudi Journal of Biological Sciences》2020,27(11):3161-3168
Despite widespread and its local available as a naturalized hedge and shade plant, the potential of Trichilia emetica was not utilized in soap making by the majority of local community in various parts of Dodoma, Tanzania. This study aimed to assess the quantity (yields) and quality (Acid Values (AVs), %Free Fatty Acids (%FFAs) and Saponification Values (SVs) of seed oil from water plant (T. emetica), suitable for soap making application. Solvent extraction method was used during oil extraction, where by 50gm of preheated and powdered seed materials were immersed in 250 ml of n-hexane in 1:5 (w/v) to dissolve the oil contained in the seed cake. The oil was collected by vaporizing solvent out through Rotary evaporation at 60 °C. Also standard titration methods were used to obtain SVs, AVs and %FFAs of the extracted oil. Results showed that T. emetica seeds contained higher quantity of oil (48.4%−50.2%) than many reported commercial plant seed oils. Also, the study found higher AV (7.4 mgKOH/g−7.8 mgKOH/g), %FFA (3.7% to 3.9%) and SVs (189.5 mgKOH/g − 191.4 mgKOH/g) than the maximum acceptable limits of 0.50 mg KOH/g, 0.020% and 175 mgKOH/g − 187 mgKOH/g prescribed by ASTM standards (2002). The obtained results showed that, T. emetica seeds yielded high oil quantity with low qualities due to higher levels of acidity. But high SVs guarantees the possibility of using T. emetica seed oil in soap making. However, the oil requires purification in order to bring levels of acidity to acceptable standards and guarantee its normal use in soap making. 相似文献