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1.
A.R. Quesada A. Cañedo M.A. Moreno J.L. Fernández-Puentes 《Letters in applied microbiology》1996,22(4):303-306
A.R. QUESADA, A. CAÑEDO, M.A. MORENO AND J.L. FERNÁNDEZ-PUENTES. 1996. A simple, rapid, sensitive and automatizable method for the detection and quantification of bacterial cell wall inhibitors has been developed. The procedure is characterized by the use of a micro-organism hypersensitive to β-lactam antibiotics that contains an inducible cytosolic β-galactosidase; this enzyme is released when the micro-organism cell wall is disrupted by the antibiotic action, and then measured by the use of a chromogenic substrate. The present method allows the detection of β-lactam traces in other non-β-lactam antibiotics, and has been successfully applied in the detection of small amounts of β-lactams in biological fluids such as milk and Actinomycetes fermentation broths. The easy automatization of this method makes it specially suitable for the screening of new antibiotics of natural origin. 相似文献
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González Díaz H Olazabal E Castañedo N Sánchez IH Morales A Serrano HS González J de Armas RR 《Journal of molecular modeling》2002,8(8):237-245
A novel method for in silico selection of fluckicidal drugs is introduced. Two QSARs that permit us to discriminate between fasciolicide and non-fasciolicide drugs (the first) and to outline some conclusions about the possible mechanism of action of a chemical (the second) are performed. The first model correctly classified 93.85% of compounds in the training series and 89.5% of the compounds in the predicting one. This model correctly classified 87.7, 93.8, 92.2 and 93.9% of compounds in leave- n-out cross validation procedures when n takes values from 2 to until 6. The model seems to be stable in around 92% of good classification in leave- n-out cross validation analysis when n>6. The second model correctly classified 70% of non-fasciolicide compounds, 85.71% of beta-tubulin inhibitors and 100% of proton ionophores in the training set. This model recognizes as proton ionophores 100% of any nitrosalicylanilides in the predicting series. Both models have a low p-level <0.05. Finally, the experimental assay of six organic chemicals by an in vivo test permit us to carry out an assessment of the model with a fairly good 100% agreement between experiment and theoretical prediction. 相似文献
3.
Size‐based interactions and trophic transfer efficiency are modified by fish predation and cyanobacteria blooms in Lake Mývatn,Iceland 下载免费PDF全文
Zeynep Ersoy Erik Jeppesen Serena Sgarzi Ignasi Arranz Miguel Cañedo‐Argüelles Xavier D. Quintana Frank Landkildehus Torben L. Lauridsen Mireia Bartrons Sandra Brucet 《Freshwater Biology》2017,62(11):1942-1952
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Furlan Lopes Cassiane Lemos Costa Alice Dionísio Jaqueline Fernanda Delgado Cañedo Andres da Rosa Renata Del Valle Garnero Analia Inacio Ribeiro José Ricardo Gunski Ricardo José 《Genetica》2022,150(5):235-246
Genetica - Known as "electric-light bugs", belostomatids potentially act as agents of biological control. The Belostoma genus has holokinetic chromosomes, interspecific variation in... 相似文献
5.
Attilio Fabbretti Letizia Brandi Dezemona Petrelli Cynthia L. Pon Nilo R. Casta?edo Ricardo Medina Claudio O. Gualerzi 《Nucleic acids research》2012,40(20):10366-10374
Furvina®, also denominated G1 (MW 297), is a synthetic nitrovinylfuran [2-bromo-5-(2-bromo-2-nitrovinyl)-furan] antibiotic with a broad antimicrobial spectrum. An ointment (Dermofural®) containing G1 as the only active principle is currently marketed in Cuba and successfully used to treat dermatological infections. Here we describe the molecular target and mechanism of action of G1 in bacteria and demonstrate that in vivo G1 preferentially inhibits protein synthesis over RNA, DNA and cell wall synthesis. Furthermore, we demonstrate that G1 targets the small ribosomal subunit, binds at or near the P-decoding site and inhibits its function interfering with the ribosomal binding of fMet-tRNA during 30S initiation complex (IC) formation ultimately inhibiting translation. Notably, this G1 inhibition displays a bias for the nature (purine vs. pyrimidine) of the 3′-base of the codon, occurring efficiently only when the mRNA directing 30S IC formation and translation contains the canonical AUG initiation triplet or the rarely found AUA triplet, but hardly occurs when the mRNA start codon is either one of the non-canonical triplets AUU or AUC. This codon discrimination by G1 is reminiscent, though of opposite type of that displayed by IF3 in its fidelity function, and remarkably does not occur in the absence of this factor. 相似文献
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The antioxidant activity of β-carotene and oxygenated carotenoids lutein, canthaxanthin, and astaxanthin was investigated
during spontaneous and peroxyl-radical-induced cholesterol oxidation. Cholesterol oxidation, measured as generation of 7-keto-cholesterol
(7-KC), was evaluated in a heterogeneous solution with cholesterol, AAPH, and carotenoids solubilized in tetrahydrofuran and
in water, and in a homogeneous solution of chlorobenzene, with AIBN as a prooxidant. The formation of 7-KC was dependent on
temperature and on cholesterol and prooxidant concentrations. All the carotenoids tested, exhibited significant antioxidant
activity by inhibiting spontaneous, AAPH- and AIBN-induced formation of 7-KC, although the overall order of efficacy of these
compounds was astaxanthin > canthaxanthin > lutein = β-carotene. The finding that carotenoids exert protective effects on
spontaneous and free radical-induced cholesterol oxidation may have important beneficial effects on human health, by limiting
the formation of atheroma and by inhibiting cholesterol oxidation in food processing or storage. 相似文献
9.
Sara Jiménez-Puertas David Sánchez-Artuñedo Marcelino Hermida-López 《Reports of Practical Oncology and Radiotherapy》2018,23(2):121-125
Aim
This work aims to achieve the highest possible monitor units (MU) reduction using the MU Objective tool included in the Eclipse treatment planning system, while preserving the plan quality.Background
The treatment planning system Eclipse (Varian Medical Systems, Palo Alto, CA) includes a control mechanism for the number of monitor units of volumetric modulated arc therapy (VMAT) plans, named the MU Objective tool.Material and methods
Forty prostate plans, 20 gynecological plans and 20 head and neck plans designed with VMAT were retrospectively studied. Each plan (base plan) was optimized without using the MU Objective tool, and it was re-optimized with different values of the Maximum MU (MaxMU) parameter of the MU Objective tool. MU differences were analyzed with a paired samples t-test and changes in plan quality were assessed with a set of parameters for OARs and PTVs.Results
The average relative MU difference considering all treatment sites, was the highest when MaxMU = 400 (?4.2%, p < 0.001). For prostate plans, the lowest was obtained (?3.7%, p < 0.001). For head and neck plans was ?7.3% (p < 0.001) and for gynecological plans was 7.0% (p = 0.002). Although similar MU reductions were observed for both sites, for some gynecological plans maximum differences were greater than 10%. All the assessed parameters for PTVs and OARs sparing showed average differences below 2%.Conclusion
For the three studied clinical sites, establishing MaxMU = 400 led to the optimum MU reduction, maintaining the original dose distribution and dosimetric parameters practically unaltered. 相似文献10.
Trophic niche,capture efficiency and venom profiles of six sympatric ant‐eating spider species (Araneae: Zodariidae) 下载免费PDF全文
Stano Pekár Lenka Petráková Ondrej Šedo Stanislav Korenko Zbyněk Zdráhal 《Molecular ecology》2018,27(4):1053-1064
The arms race between specialist predators and their prey has resulted in the evolution of a variety of specific adaptations. In venomous predators, this can include venom composition, particularly if predators are specialized on dangerous prey. Here, we performed an integrative study using six species of highly specialized ant‐eating spiders of the genus Zodarion to investigate their phylogeny, realized trophic niche, efficacy in the capture of various ant species and venom composition. Data on natural diet obtained by next‐generation sequencing and field observations showed that the six Zodarion species exploit different ant species. Their phylogeny, based on mitochondrial and nuclear genes, correlated with the composition of their natural prey, indicating that closely related Zodarion species specialize on similar ant species. Prey‐capture parameters differed among Zodarion species suggesting prey‐specific efficacy. Similarly, the venom profiles of both low and high molecular compounds differed among species. Only the profiles of low molecular compounds were correlated with capture efficacy parameters, suggesting that the venom of Zodarion spiders contains prey‐specific components. Our study suggests that Iberian Zodarion spiders are specialized on particular ant species. 相似文献