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排序方式: 共有216条查询结果,搜索用时 15 毫秒
1.
José Edmundo Nava Saucedo Jean-Noël Barbotin Daniel Thomas 《Applied microbiology and biotechnology》1989,30(3):226-233
Summary The continuous production of gibberellic acid with immobilized mycelia of Gibberella fujikuroi was maintained over a hundred days in a tubular fixed-bed reactor. Free mycelium at the beginning of the storage phase was harvested from G. fujikuroi shake-flask culture and was immobilized by ionotropic gelation in calcium alginate beads.The continuous recycle production system consisted of a fixed-bed reactor, a container in which the culture medium was heated, stirred and aerated, and valves for sample withdrawal or reactant addition during the first 1320 h (55 days). A two-phase continuous extractor was then added for the last 960 hours (40 days). Free and immobilized mycelium shake-flask cultures with the same strain used in the continuous culture system were also realized to compare growth, maintenance and production parameters. The results show about the same gibberellic acid productivity in both free and immobilized mycelium shakeflask cultures: 0.384 and 0.408 mgGA3·gBiomass-1 ·day-1, respectively, whereas in the continuous system the gibberellic acid production is about twice as large for a similar biomass: 0.768 mgGA3·gBiomass-1·day-1. Several factors affecting the overall productivity of the immobilized systems were found to be: the quality and the quantity of mycelia in the biocatalyst beads and the immobilization conditions. 相似文献
2.
Nichola J. K. Hole Edmundo Lamoyi Masanori Komatsu Nagaradona Harindranath Glendowlyn O. Young-Cooper Rose G. Mage 《Immunogenetics》1988,28(2):99-107
In order to investigate linkage, we used serum allotypes of the two rabbit C
isotypes and restriction fragment length polymorphisms (RFLPs) of the genes for V
, C
, and T-cell receptor C
. The inheritance of these genetic markers was studied through backcross and F2 matings. Southern analysis and hybridization of genomic DNA with a C probe detected a 5 kb Pst I fragment linked to expression of the K2bas1 allotype and the presence of the 1b
bas gene and a 6.6 kb Pst I fragment linked to the expression of the K1b9 allotype, the presence of the 2
bas2 gene and lack of expression of the K2bas1 allotype. A V probe detected a 1.3 kb Eco RI fragment linked to the presence of the 1b
bas gene and expression of the K2bas1 allotype. In contrast, the 9 or 14 kb Eco RI RFLP (C
a or C
b) detected with a Tcr
chain probe segregated independently from C allotypes and RFLPs. It has previously been found that C and C
are also unlinked in man, whereas in the mouse they are linked at a distance of 8 centimorgans. 相似文献
3.
Yesenia Pacheco-Hernández Edmundo Lozoya-Gloria Maricruz Rangel-Galván Jenaro Leocadio Varela-Caselis Nemesio Villa-Ruano 《化学与生物多样性》2023,20(10):e202301034
We present the inhibitory properties of the R. pompana anthocyanin fraction (RPAF) and its major constituents on alpha-glucosidase (AG), pancreatic lipase (PL), HMG-CoA reductase, and ornithine decarboxylase (ODC). The effect of RPAF was also evaluated in ICR male mice subjected to oral glucose tolerance test (OGTT) and hypercaloric/atherogenic diet for 30 days. RP-HPLC/MS profiling revealed that RPAF contained five major anthocyanins and induced slight inhibition on PL and HMG-CoA reductase (IC50, 245–338 μg mL−1) whereas strong activity on AG and ODC (IC50, 130–133 μg mL−1) was observed. Kinetic studies and molecular docking with pelargonidin-3-O-rutinoside (P3R) on ODC, revealed changes in Km (0.9514–0.9746 mM) and Vmax (1.96–2.32 μmol mg−1 min−1) suggesting mixed inhibition and molecular interaction with two active sites of ODC. P3R showed antiproliferative activity (IC50, 46.5 μM) and decreased polyamine accumulation in DLD-1 cells. The results of OGTT confirmed that RPAF regulates postprandial glucose levels in diabetic animals which experienced a significant glucose depletion (30 %; p<0.001) from 30 to 120 min post-treatment. Prolonged supplementation of RPAF caused significant decrease (p<0.001) in plasma glucose, total cholesterol, LDL-c and triglycerides as well as significant increase (p<0.001) of HDL-c compared with normoglycemic untreated animals. 相似文献
4.
This report describes experimental results which show that the fluorescent reagent fluorescamine induces mitochondrial energy-independent swelling when the incubation media contain the chloride salts of the cations Li+, Na+, K+, Rb+, and Cs+. The reaction depends on the concentration of the dye and is inhibited by Mg2+, and its extension is closely related to the amount of the primary amino groups titrated by fluorescamine. Analysis of the labeled inner membrane in polyacrylamide gel shows that the amount of aminofluorescamine complex is lower when mitochondria are in the presence of Mg2+. 相似文献
5.
6.
The effect of the local anesthetic tetracaine on some functions of rat heart mitochondria was studied, and the results show that this tertiary amine inhibits the oxidation of NAD-dependent substrates by affecting the mitochondrial membrane in a site located between the NADH dehydrogenase and Co Q span through a process which is not affected by K+, Ca2+, or Mg2+. Also the results show that tetracaine induces sodium uptake probably by a H+/Na+ exchange reaction. 相似文献
7.
During a period of three years, 256 diagnostic bronchoscopies were done with flexible fiberoptic bronchoscopes at a Veterans Administration hospital. In all of these procedures, topical cocaine hydrochloride anesthesia was used, and it proved satisfactory and free of any undesirable side effects.The peroral route using an endotracheal tube is preferred for flexible bronchofiberscopy. Fluoroscopic guidance is essential in examining peripheral lung lesions. A 70 percent positive yield was obtained for patients with peripheral carcinoma of the lung as contrasted to a 47 percent yield when the tissue specimens were obtained blindly. 相似文献
8.
Yesenia Pacheco-Hernández Carlos Jonnathan Castro-Juárez Sergio Alberto Ramírez-García Ramiro Cruz-Durán Edmundo Lozoya-Gloria Nemesio Villa-Ruano 《Journal of Asia》2021,24(2):243-249
Preventive measures based in the control of insect vectors are considered as the best choice to decrease the incidence of insect-borne diseases. Herein we report on the volatile content of the leaf essential oils from Marina neglecta, a medicinal plant distributed in the tropical regions of southern Mexico. In order to investigate the chemical variation of the essential oils, a volatile screening was performed during the four seasons of the years 2016–2019. Simultaneously, their biological activity was tested on distinct life stages of Meccus pallidipennis, M. bassolsae, Aedes aegypti and A. albopictus. Essential oils were mainly constituted of β-pinene (>30%) β-caryophyllene (>25%) and germacrene D (>13%). Dorsal-abdomen application of essential oils on triatomines, revealed an efficient LC50 for nymphs of the stages I to III (4 µg/insect), nymphs of the stages IV to V (5–6 µg/insect), and adults (7–8 µg/insect). The LT50 for the stages I to III was between 6 and 8 h, whereas that for the stages IV to V and adults oscillated between 12 and 16 h and 22 to 26 h, respectively. Fumigation experiments performed on nymph V, demonstrated that 300 µg L?1 air produced 100% mortality after 72 h post-treatment. Among tested volatiles, β-pinene and β-caryophyllene produced a comparable mortality rate (p < 0.01) than that of essential oils in the stages assayed. Essential oils showed strong larvicidal (LC50, 24–36 µg mL?1) and adulticidal (35–48 µg mL?1) activities in mosquito species with an LT50 of 4.5 h and 25–35 min, respectively. The evaluation of β-pinene produced a significant mortality rate (p < 0.01) in larvae whereas germacrene D was the most effective volatile (p < 0.01) against adults of both mosquito species. According to our results, β-pinene was the most effective volatile against the four insect species evaluated and its effect was comparable to that of the essential oil. 相似文献
9.
Caio Loureiro Salgado Emmanoel Loss Dias Lorenzzo Lyrio Stringari Luciana Polaco Covre Reynaldo Dietze Fausto Edmundo Lima Pereira Herbet Leonel de Matos Guedes Bartira Rossi-Bergmann Daniel Claudio Oliveira Gomes 《Microbes and infection / Institut Pasteur》2019,21(7):328-335
The use of adjuvants in vaccine formulations is a well-established practice to improve immunogenicity and protective immunity against diseases. Previously, we have demonstrated the feasibility of intranasal vaccination with the antigen of killed Leishmania amazonensis promastigotes (LaAg) against experimental leishmaniasis. In this work, we sought to optimize the immunogenic effect and protective immunity against murine visceral leishmaniasis conferred by intranasal delivery of LaAg in combination with a synthetic TLR1/TLR2 agonist (Pam3CSK4). Intranasal vaccination with LaAg/PAM did not show toxicity or adverse effects, induced the increase of delayed-type hypersensitivity response and the production of inflammatory cytokines after parasite antigen recall. However, mice vaccinated with LaAg/PAM and challenged with Leishmania infantum presented significant reduction of parasite burden in both liver and spleen, similar to those vaccinated with LaAg. Although LaAg/PAM intranasal vaccination had induced higher frequencies of specific CD4+ and CD8+ T cells and increased levels of IgG2a antibody isotype in serum, both LaAg and LaAg/PAM groups presented similar levels of IL-4 and IFN-y and decreased production of IL-10 when compared to controls. Our results provide the first evidence of the feasibility of intranasal immunization with antigens of killed Leishmania in association with a TLR agonist, which may be explored for developing an effective and alternative strategy for vaccination against visceral leishmaniasis. 相似文献
10.
Araújo-Jorge TC Cardona TS Mendes CL Henriques-Pons A Meirelles RM Coutinho CM Aguiar LE Meirelles Mde N de Castro SL Barbosa HS Luz MR 《Cell biology education》2004,3(2):99-110
The advent of genomics, proteomics, and microarray technology has brought much excitement to science, both in teaching and in learning. The public is eager to know about the processes of life. In the present context of the explosive growth of scientific information, a major challenge of modern cell biology is to popularize basic concepts of structures and functions of living cells, to introduce people to the scientific method, to stimulate inquiry, and to analyze and synthesize concepts and paradigms. In this essay we present our experience in mixing science and education in Brazil. For two decades we have developed activities for the science education of teachers and undergraduate students, using microscopy images generated by our work as cell biologists. We describe open-air outreach education activities, games, cell modeling, and other practical and innovative activities presented in public squares and favelas. Especially in developing countries, science education is important, since it may lead to an improvement in quality of life while advancing understanding of traditional scientific ideas. We show that teaching and research can be mutually beneficial rather than competing pursuits in advancing these goals. 相似文献