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51.
T. Corrêa de Souza P. César Magalhães F. José Pereira E. Mauro de Castro S. Netto Parentoni 《Acta Physiologiae Plantarum》2011,33(5):1877-1885
This study was carried out to evaluate maize plants of different recurrent selection cycles of the variety (Zea mays L.—Saracura-BRS-4154) regarded to genetic gains, morphophysiology, and grain yield, achieved over the selection cycles under
intermittent flooding of the soil. This variety has the capacity to survive and produce in temporarily flooded soils and was
developed by the National Maize and Sorghum Research Center (EMBRAPA). The experiment was conducted in greenhouse by using
ten alternating selection cycles (Cycle 1–18) and BR 107 a variety known for its susceptibility to flooding. The flooding
initiated at six-leaf stage by applying 50 mm of water three times a week. At flowering, the following parameters were evaluated:
rate of leaf photosynthesis, stomatal conductance, intercellular CO2 concentration, transpiration rate, photosynthetically active leaf area, root porosity, relative chlorophyll content, grain
yield, harvest index, ear length, and interval between male and female flowering. Yield as a function of root porosity and
photosynthesis were also evaluated. An index was created in this study, in order to help the discussion of the characteristics
evaluated, it was called “Relative Tolerance Value—RTV”, only gaseous exchange measurements was not included in this index.
By the way, it was observed throughout the selection cycles an increase in all gaseous exchange parameters, being the cycle
18, the one which presented the greatest averages. RTV for leaf area showed the greatest values for cycles 7 and 18, whereas
root porosity, chlorophyll relative content, and harvest index, the greater RTV values were found in cycles 17 and 18. The
largest grain yield RTV was observed in cycle 7, followed by cycles 13, 15, and 18. Flooding resulted in longer Anthesis-Silking
Interval, especially for the first cycles. At flooding condition, grain yield was strongly related to root porosity (R
2 = 0.66). These results showed that the selection cycles of “Saracura” maize improved some morphophysiologic characters, which
favor their survival in flooded environments, also resulting in higher productivity. 相似文献
52.
Duangrudee Cherdwongcharoensuk Maria João Oliveira Artur Perez Águas 《Biological trace element research》2010,136(2):197-203
The in vivo dynamics of selenium (Se) and mercury (Hg) interaction was studied in mouse tissues using direct visualization
of individual Se, Hg, and SeHg particles on the surface of circulating erythrocytes. This high-resolution detection of Se
and Hg was obtained by scanning electron microscopy coupled to X-ray microanalysis. BALB/c mice were injected in the peritoneal
cavity with Se and Hg salts, and the animals were sacrificed 3 min after the Hg injection. Only a minority (9%) of the metal
dots seen on mouse liver erythrocytes were SeHg complexes when Se and Hg salts were mixed together before injection. In contrast,
the majority (73%) of metal dots on liver erythrocytes were SeHg complexes if Se was injected at least 5 min before Hg injection.
All metal dots on liver erythrocytes were of SeHg complexes if Se was injected 9 or 12 min before the Hg injection. We conclude
that the formation of stable in vivo SeHg complexes requires preliminary interaction of Se with a putative serum factor before
complexes between Se and Hg are formed and are bound to the erythrocyte cell surface. 相似文献
53.
Alves Leticia Rodrigues Rossatto Davi Rodrigo Rossi Mônica Lanzoni Martinelli Adriana Pinheiro Gratão Priscila Lupino 《Protoplasma》2020,257(2):597-605
Protoplasma - The application of Se to plants growing under Cd contamination may become an alternative strategy to minimize Cd damage. However, there is no specific information available regarding... 相似文献
54.
Dos Santos RA Batista J Rosa SI Torquato HF Bassi CL Ribeiro TA De Sousa PT Bessera AM Fontes CJ Da Silva LE Piuvezam MR 《Parasitology》2011,138(10):1224-1233
Leishmaniasis is one of the neglected diseases. High cost, systemic toxicity, and diminished efficacy due to development of resistance by the parasites has a negative impact on the current treatment options. Thus, the search for a new, effective and safer anti-leishmanial drug becomes of paramount importance. Compounds derived from natural products may be a better and cheaper source in this regard. This study evaluated the in vitro anti-leishmanial activity of Spiranthera odoratíssima (Rutaceae) fractions and isolated compounds, using promastigote and amastigote forms of different Leishmania species. J774 A.1 macrophage was used as the parasite host cell for the in vitro assays. Evaluations of cytoxicity, nitric oxide (NO), interleukin-10 and in silico analysis were carried out. In vitro experiments showed that the fruit hexanic fraction (Fhf) and its alkaloid skimmianine (Skm) have a significant (P<0·001) effect against L. braziliensis. This anti-L. braziliensis activity of Fhf and Skm was due to increased production of NO and attenuation of IL-10 production in the macrophages at concentrations ranging from 1·6 to 40·0 μg/ml. The in silico assay demonstrated significant interaction between Skm and amino acid residues of NOS2. Skm is thus a promising drug candidate for L. braziliensis due to its potent immunomodulatory activity. 相似文献
55.
Marques MP Girão T Pedroso De Lima MC Gameiro A Pereira E Garcia P 《Biochimica et biophysica acta》2002,1589(1):63-70
Cytotoxicity and cell growth inhibition studies were performed for three distinct polynuclear platinum(II) complexes of spermidine, which showed to have significant cytotoxic and antiproliferative properties on the HeLa cancer cell line. The chemical environment of the metal centres in the drugs, as well as the coordination pattern of the ligand, were found to be strongly determinant of their cytotoxic ability. In the light of the results gathered, the most effective anticancer compound among the ones tested (IC50=5 microM) was found to be the one displaying three difunctional (PtCl2N2) moieties ((PtCl2)3(spd)2). Both the cytotoxic activity and the antiproliferative properties of the complexes studied showed to be irreversible for all the concentrations tested. 相似文献
56.
Encarnação JM Rosa L Rodrigues R Pedro L da Silva FA Gonçalves J Ferreira GN 《Journal of biotechnology》2007,132(2):142-148
In this work three piezoelectric sensors modified with anti-HIV-1 Vif (virion infectivity factor) single fragment antibodies (4BL scFV), single domains (VH) and camelized single domains (VHD) were constructed and used to detect HIV1 Vif in liquid samples. Dithio-bis-succinimidyl-undecanoate (DSU) and 11-hydroxy-1-undecanethiol (HUT) mixed self assembled monolayers (SAM) were generated at the sensors surface onto which the antibodies were immobilized. All sensors detected specifically the target HIV1-Vif antigen in solution and no unspecific binding was monitored. Impedance analysis was performed to quantify electroacoustic and viscoelastic interferences during antibody immobilization and antigen recognition. The elimination of such interferences enabled the quantitative use of the piezoelectric immunosensors to estimate the antibody surface density as well as antigen binding and equilibrium constants. In spite of the possible limitation regarding mass transport and other related molecular phenomena, which were not considered in the binding model used, this work demonstrates the usefulness of piezoelectric biosensors in biorecognition analysis and evidences the advantages on using simultaneous impedance analysis to bring analytical significance to measured data, and thus to improve piezoelectric sensors sensitivity and applicability. 相似文献
57.
Christian G. Ramos André M. Grilo Sílvia A. Sousa Marta L. Barbosa Helena Nadais Jorge H. Leitão 《Applied microbiology and biotechnology》2010,85(3):801-806
This work describes a methodology combining DNA extraction, polymerase chain reaction amplification with primers targeting 16S ribosomal RNA genes, cloning, and sequencing of clones previously analyzed by restriction fragment length polymorphism (RFLP), which can be applied to study the microbial diversity in a given habitat. The methodology allows the minimization of the sequencing effort, which is particularly relevant when analyzing large numbers of clones. The methodology does not require particularly skilled personnel and can easily be adaptable to the molecular characterization of virtually any particular microbial population, provided that both adequate primers and suitable restriction enzymes for RFLP analysis of the clone library have been chosen. An example of application is presented, in which a sample taken from a continuously operating upflow anaerobic sludge blanket reactor was analyzed. RFLP analysis of the initial 162 clones with HaeIII allowed the identification of only 28 distinct profiles. As expected, identical RFLP profiles corresponded to identical nucleotide sequences. 相似文献
58.
In mammals, milk provision is crucial to offspring survival and growth from birth to weaning. Milk deficiency early in life may cause death or changes in the progeny metabolism that later may lead to obesity and metabolic disorders. This study investigates milk ejection (ME) the first day after birth (D1) in F2 females from the intercross of LG/J and SM/J inbred mice strains. The absence of milk in F3 pups?? stomach at D1 is directly associated with their survival (p?<?0.001) and growth pattern (p?<?0.001) in the early stages of life. Furthermore, late growth pattern is also affected by this lack of nutrients at D1 because pups that survive this absence, mostly males, are heavier at weaning (p?<?0.001) which, after necropsy, is shown to be due to significant higher total fat deposition (p?<?0.01). We performed QTL analysis for ME at D1 in these F2 females. Maternal performance of ME revealed a complex genetic architecture which even though it contains only a single QTL (accounting for 8?% of the variation in ME), it is totally context-dependent on the genetic background. We discovered many regions involved in epistatic interactions that together with the single QTL explain 19?% of the genetic variation for this trait. Milk ejection is an important component of maternal care, and understanding the mechanisms modulating its variation, along with other maternal features, may help to disentangle the complexity that is the mother/offspring relationship. 相似文献
59.
Camilios-Neto D Bugay C de Santana-Filho AP Joslin T de Souza LM Sassaki GL Mitchell DA Krieger N 《Applied microbiology and biotechnology》2011,89(5):1395-1403
Rhamnolipid biosurfactants are attracting attention due to their low toxicity, high biodegradability, and good ecological
acceptability. However, production in submerged culture is made difficult by severe foaming problems. Solid-state cultivation
(SSC) is a promising alternative production method. In the current work, we report the optimization of rhamnolipid production
by Pseudomonas aeruginosa UFPEDA 614 on a solid substrate containing sugarcane bagasse and corn bran. The best rhamnolipid production, 45 g/l of impregnating
solution used, was obtained with a 50:50 (m/m) mixture of sugarcane bagasse and corn bran supplemented with an impregnating
solution containing 6% (v/v) of each of glycerol and soybean oil. This level is comparable with those of previous studies
undertaken in solid-state cultivation; the composition of the biosurfactant is similar, but our medium is cheaper. Our work
therefore provides a suitable basis for future studies of the development of an SSC-based process for rhamnolipid production. 相似文献
60.