448 results on '"Silva, R. S."'
Search Results
252. ChemInform Abstract: A SIMPLE SYNTHESIS OF 1-PHENOTHIAZINEETHANOLAMINES: POTENTIAL ANTIMALARIALS
- Author
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PINTO, A. C., primary, DA SILVA, R. S., additional, and HOLLINS, R. A., additional
- Published
- 1980
- Full Text
- View/download PDF
253. ChemInform Abstract: Electron and Hydrogen Atom Transfer Mechanisms for the Photoreduction of o-Quinones. Visible Light Induced Photoreactions of β-Lapachone with Amines, Alcohols, and Amino Alcohols.
- Author
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CI, X., primary, DA SILVA, R. S., additional, NICODEM, D., additional, and WHITTEN, D. G., additional
- Published
- 1989
- Full Text
- View/download PDF
254. Unveiling the pressure-induced scheelite to M′-fergusonite phase transition in NaCe(MoO4)2.
- Author
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Ferreira, W. C., Alabarse, F. G., Luz-Lima, C., Silva, R. S., Olivier, L. S. A., Freire, P. T. C., Lima Jr., J. A., and Moura, J. V. B.
- Subjects
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PHASE transitions , *SCHEELITE , *ENVIRONMENTAL remediation , *STRUCTURAL stability , *RAMAN spectroscopy , *SYNCHROTRONS - Abstract
Sodium-cerium molybdate, NaCe(MoO4)2, belongs to the family of double alkaline rare-earth molybdate, and it holds significant importance across various technological domains, such as environmental remediation and energy conversion. Despite its importance, the behavior of NaCe(MoO4)2 under high-pressure conditions remains unexplored. This study uses synchrotron x-ray diffraction and Raman spectroscopy to investigate NaCe(MoO4)2in situ under high-pressure conditions. We observed a pressure-induced phase transition from the scheelite to the M ′ -fergusonite structure type on a double molybdate at approximately 10 GPa. These findings contribute to a deeper understanding of the structural stability of NaCe(MoO4)2 and shed light on the broader field of high-pressure studies of double molybdates. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
255. Isothermal vapor-liquid equilibrium data by total pressure method. Systems acetaldehyde-ethanol, acetaldehyde-water, and ethanol-water
- Author
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D'Avila, S. G., primary and Silva, R. S. F., additional
- Published
- 1970
- Full Text
- View/download PDF
256. 0.7 pA/V transconductor allowing Gm-C filters in range of mHz using sub-pF capacitors.
- Author
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Rodrigues, C. R. and Silva, R. S.
- Subjects
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ELECTRICAL conductors , *CAPACITORS , *ELECTRIC impedance , *ATTENUATION (Physics) , *INTEGRATORS , *COMPUTER simulation - Abstract
A new topology of a transconductor suitable for the implementation of transconductance-C (Gm-C) integrators with time constants of tens of seconds using sub-pF capacitors is introduced. The proposed circuit relies on a cascode stage driven backwards, i.e. the input signal is applied to the cascode output node. The key point is taking advantage of the high impedance of the cascode to impose high attenuation to the input signal and to establish transconductances in the order of fA/V. The concept is demonstrated at the simulation level by realising a Gm-C integrator with a time constant of 100 s. The integrator comprises a 0.7 pA/V transconductor and an 800 fF capacitor at its output. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
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257. The new NO-donor does not induce in vitro tolerance in rat aorta.
- Author
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Banin, T., Pernomian, L., da Silva, R. S., and Bendhack, L. M.
- Subjects
NITRITES ,ENDOTHELIAL cells ,SMOOTH muscle - Abstract
The nitrite anion (NO2-) can be the major source of intravascular and tissue storage of nitric oxide (NO), important modulator of vascular tone and blood pressure. The NO donor RUBPY synthesized by our group, releases NO inside the vascular smooth muscle cell in a tissue dependent manner. Long-term treatment with organic nitrates like nitroglycerin, leads to the development of tolerance characterized by the rapid loss of vasodilator effects. Tolerance is a multifactorial process. It may be due to endothelial dysfunction that involves increased production of vascular reactive oxygen species (ROS), decreased activity of soluble guanylyl-cyclase and increased phosphodiesterase expression and activity. This study aimed to investigate the in vitro tolerance to the pre-exposure of intact endothelium aorta (e+) or denuded aorta (e-) with RuBPY (EC100:10 µM). It was also evaluate if the compound releases NO in the endothelial cells in the incubation time studied. The aortic rings were isolated and used for the functional studies. Aortic rings (e+/e-) were contracted with phenylephrine, and after reaching a stable and maintained contraction, RuBPY (3 nM-5 µM) was added to the organ bath. Experiments were conducted after pre-exposure to RuBPY (tolerance) or in the absence of RuBPY (control). The maximum effect (ME) and potency (pD2) of RuBPY in inducing relaxation were evaluated. Endothelial cells were incubated with the fluorescent dye DAF-2/DA (10 µM) to quantifying the cytosolic NO and DHE (2.5 µM) to quantifying ROS. The intensity of fluorescence was detected in the absence or after exposure to RuBPY at different times (5-60min). This study was approved by the Ethical Animal Committee of the University of São Paulo (2012.1.134.53.12). The compound RuBPY induced concentration-dependent relaxation in e+ aortas (pD2:7.81±0.18; ME:101.6± 1.4%, n=7) and e- (pD2:7.54±0.13; ME:103.4±0.4%, n=6). The incubation with 10 µM RuBPY for 5 min followed by 20 min of washout did not affect the ME induced by the compound in e+ aorta (pD2:7.99±0.18; ME:98.5 ±1.6%, n=5) or in e- aortas (pD2:7.89±0.18, ME:100.0 ±0.4%, n=6). Pre-exposure for 10 min with RuBPY in e+ aortas did not alter the relaxation to RuBPY compared to respective control. However, in e- aortas the relaxing effect of RuBPY was potentiated (pD2:7.37±0.12, ME:101.5±1.0%, n=5, P<0.05). Pre-exposure for 30 min with RuBPY did not change the relaxation to RuBPY in e- aortas as compared to the control. RuBPY did not release NO and ROS in the endothelial cells up to 60 min incubation. Taking together, our results demonstrate that the new NO donor RuBPY does not induce tolerance in rat aorta, which is probably due to the lack effect of RuBPY on the endothelial cells. Supported by FAPESP and CNPq. [ABSTRACT FROM AUTHOR]
- Published
- 2013
258. The new nitric oxide donor (RuBPY) induces tolerance only after 60 minutes exposure and it does not induce cross-tolerance with acetylcholine.
- Author
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Paulo, M., Grando, M. D., Vercesi, J. A., da Silva, R. S., and Bendhack, L. M.
- Subjects
NITRIC oxide ,NITROGLYCERIN ,ACETYLCHOLINE - Abstract
Nitric oxide (NO) donors like nitroglycerin (GTN) are widely used as pharmacological tool to understand the physiological effect of NO, and in the treatment of cardiovascular diseases. The major therapeutic limitation of GTN is the tolerance that is characterized by rapid loss of its effects in long-term administration, or cross-tolerance to other vasodilator, which cause(s) is still not clear. It is endothelium-dependent and the uncoupling endothelial NO-synthase (eNOS) could contribute to the tolerance. The major clinical benefit of organic nitrates, including the GTN has been attributed to their potent venodilator effect. This study aimed to verify if the new NO donor synthesized in our laboratory (RuBPY) induces in vitro tolerance and cross-tolerance to acetylcholine and sodium nitroprusside (SNP) in rat cava vein. We compared the effects of RuBPY with GTN in relation to the maximum effect (ME) and potency (pD2). In vitro tolerance was induced by incubation for 10, 30 or 60 min with RuBPY (2 µM or 10 µM) or GTN (4 µM or 0.1mM). In vitro cross-tolerance to acetylcholine and SNP was induced by the veins pre-incubation with RuBPY (2 µM) or GTN (4 µM) for 60 min. The eNOS phosphorylated in the activation site (Ser1177) and in the inactivation site (Thr495) was accessed by Western Blotting. The cytosolic concentration of NO ([NO]c) was measured by flow cytometry and confocal microscopy. Our results demonstrated that RuBPY induced greater relaxation (ME: 92.8 ± 4.4%; n=7, P<0.05) than GTN (ME: 75.3 ± 3.7%, n=6). Both NO donors increased [NO]c in vascular smooth muscle cells. Previous exposure for 10 min with RuBPY (2 µM or 10 µM) or GTN (4 µM or 0.1mM) did not induce tolerance. However, 30 min pre-exposure did not change the relaxation to RuBPY, but it reduced the relaxation to GTN (with 4 µM, ME: 45.4 ± 2.2%, n= 6, P<0.05, and 0.1 mM, ME: 39.2 ± 1.4%, n= 6, P<0.05). Pre-exposure for 60 min with RuBPY reduced the relaxation in the concentrations of 2 µM (ME: 48.0 ± 2.3%, n= 7, P<0.05) and to 10 µM (ME: 30.1±1.2%, n= 7, P<0.05). Pre-exposure to RuBPY or GTN did not reduce the relaxation to SNP. Cross-tolerance to acetylcholine was induced only with GTN. The ME stimulated with acetylcholine was reduced from100.3 ± 5.3% to 75.1 ± 4.2% (n=7, P<0.05). Whereas RuBPY and GTN had phosphorylated eNOS in Thr495, only GTN phosphorylated eNOS-Ser1177. In conclusion, our data demonstrate that RuBPy induces tolerance in both concentrations, only after 60 min exposure. It does not induce cross-tolerance to acetylcholine and SNP. It does not interfere with the activation site of eNOs. Supported by FAPESP and CNPq. [ABSTRACT FROM AUTHOR]
- Published
- 2013
259. Reactive oxygen species potentiate vasodilator effect of nitric oxide donor with gold nanoparticles in aortas from renal hypertensive rats.
- Author
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Silva, B. R., Silva, R. S. da, and Bendhack, L. M.
- Published
- 2011
260. Fortification of bread with L-lysine HCl: Losses due to baking process
- Author
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Rao, C. S., Saab, R. M. G. B., and Da Silva, R. S. F.
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FOOD industry ,LYSINE ,NUTRITION - Published
- 1981
261. A new procedure to synthesize cis-[Ru(NH~3)~4L~2]^n^+ species containing ruthenium(II) or ruthenium(III) using tetrammino-(3,4-diolatobenzoato)ruthenium(II) as precursor
- Author
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Silva, R. S. Da, Tfouni, E., and Lever, A. B. P.
- Published
- 1995
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- View/download PDF
262. Improving the microwave dielectric properties of BiCu3Ti3FeO12 with the addition of Bi2O3.
- Author
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Colares, D. da M., Abreu, R. F., Silva, F. R., Abreu, T. O., Nobrega, F. A. C., Freitas, D. B., do Nascimento, J. P. C., Oliveira, F. G. S., Vasconcelos, I. F., Ghosh, A., Vasconcelos, S. J. T., Sales, J. C., Silva, R. S., and Sombra, A. S. B.
- Subjects
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DIELECTRIC properties , *DIELECTRIC resonator antennas , *DIELECTRIC loss , *MICROWAVES , *SCANNING electron microscopy - Abstract
In this work, the influence of the addition of Bi2O3 on the dielectric properties in the microwave range of BiCu3Ti3FeO12 (BCTFO) ceramic matrix and its potential application as a dielectric resonator antenna are analysed. X-ray diffraction shows that a reaction between BCTFO and Bi2O3 occurs that results in the formation of new crystalline phases. The morphology of the samples is studied by field-emission scanning electron microscopy and demonstrates a dependence of the grain size on the Bi2O3 content. From the Mössbauer spectroscopic analysis, it is found that the Fe3+ ions replace the Ti4+ in the crystalline structure. The addition of Bi2O3 also reduces the dielectric permittivity (ϵr), dielectric loss (tan δ) and the coefficient of the resonance frequency (τf) values. Finally, numerical simulations are carried out in order to obtain the antenna parameters and they demonstrate that BCTFO could be a potential candidate for devices operating in the S-band. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
263. 14b-Chloro-4a-methoxy-3,3-dimethyl-2,3,4a,14b-tetrahydro-1 H-benzo[ a]pyrano[2,3- c]phenazine: a new active structural type against Mycobacterium tuberculosis.
- Author
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Nunes, I. K. da C., De Simone, C. A., Silva, R. S. F., Pinto, A. V., and Goulart, M. O. F.
- Subjects
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MYCOBACTERIUM tuberculosis , *MYCOBACTERIUM , *LUNG diseases , *PHARMACEUTICAL chemistry , *CHEMISTRY - Abstract
The title compound, C22H21ClN2O2, obtained from the reaction of the phenazine of β-lapachone with trichloroisocyanuric acid, showed a minimum inhibitory concentration of 6.25 ng ml−1 in tuberculostatic assays against Mycobacterium tuberculosis and established a new structural type with potential interest in medicinal chemistry. The dihydropyran ring adopts a pure chair conformation, while the ring fused to it has a half-chair conformation. The two substituents, OMe and Cl, are in axial positions, due to anomeric effects towards the methoxy derivative. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
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264. OS (DES)AMORES NOS CONTOS DE EMILIA PARDO BAZÁN: TRADUÇÃO COMENTADA
- Author
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BYLAARDT, R. Z., SILVA, R. S., Oliveira, E., SILVA, C. T., REZENDE-FOHRINGER, K., and CASER, M. M.
- Abstract
Made available in DSpace on 2018-08-01T23:43:54Z (GMT). No. of bitstreams: 1 tese_11779_Dissertação final - 11 de março de 2018.pdf: 937031 bytes, checksum: 1289572c758c2167480604e99d3fd7db (MD5) Previous issue date: 2018-02-22 Propõe-se a leitura e tradução dos contos El amor asesinado, El dominó verde, La novia fiel, El encaje roto e Sangre del brazo, de Emilia Pardo Bazán, escritora espanhola da segunda metade do século XIX e começo do século XX. Com essa tradução, busca-se aprofundar a leitura da obra da autora, atentando em particular para a organização sintático-semântica do texto. Com uma visão pessimista do amor, Pardo Bazán faz de seus contos espelhos que refletem a situação da mulher e dos que a cercam. O relacionamento de casal é o tema central, destacando-se, de forma especial, o fracasso amoroso e a não realização dos sonhos de conquista da felicidade ao lado do ser amado. Apoiam-nos neste trabalho os escritos de Pilar Folguera Crespo (1997) em Historia de las mujeres en España, para a observação dos papéis de gênero registrados nos escritos de Pardo Bazán, de Ángeles Quesada Novás (2005), para o estudo do amor nos contos analisados, de Michaël Oustinoff (2011), para a discussão do traduzir como operação fundamental da linguagem, e de Antoine Berman (2007), para a questão da eticidade na tradução. Palavras-chave: Emilia Pardo Bazán- Cuentos de amor. Questões de gênero. Tradução do texto literário.
- Published
- 2018
265. Dos Pés à Cabeça: Moda e Modos em Sapato de Salto de Lygia Bojunga
- Author
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APOLINARIO, D. S., SILVA, R. S., GABRECHT, A. P., Coser, S., REZENDE-FOHRINGER, K., and CASER, M. M.
- Abstract
Made available in DSpace on 2018-08-01T23:43:50Z (GMT). No. of bitstreams: 1 tese_10667_Dissertação - Danielle da Silva Apolinario - PPGL - Jan 2017.pdf: 689295 bytes, checksum: 451bdbdd40610e58c2b2c6680484aa12 (MD5) Previous issue date: 2017-02-21 O presente trabalho analisa as personagens femininas, na obra Sapato de Salto da escritora brasileira Lygia Bojunga, e busca por meio dos elementos da moda que as calça, apontar como esses artefatos, muitas vezes, impostos às mulheres, são apresentados no enredo. A escritora, ao lado de outras autoras que produzem, de maneira especial, literatura infanto-juvenil, questiona em suas narrativas os valores defendidos pela sociedade patriarcal, propiciando aos jovens leitores espaço para a revisão de suas crenças e atitudes, que se refletem na aparência física exibida por homens e mulheres. Utiliza-se para a análise da questão de gênero o aporte teórico dos estudos, entre outros, de Guacira Lopes Louro por preterir os esquemas dicotômicos de pensamento, por pensar em termos de pluralidades e diversidades, além de se opor às abordagens essencialistas. A reflexão sobre a moda segue o viés das pesquisas de Diana Crane; Gilles Lipovetsky; Linda OKeeffe e RachelleBergstein. Palavras-chave: Sapato de salto-personagens femininas. Gênero-Modos e moda. Literatura infantil/juvenil.
- Published
- 2017
266. The increasing inclusion of technologies in histology teaching: A systematic review.
- Author
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E Silva RS, de Lima P, Guedert DG, Freire GDCL, and Cerqueira GS
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- Humans, Computer-Assisted Instruction methods, Curriculum, Digital Technology, Educational Technology trends, Learning, Microscopy methods, Teaching, Histology education
- Abstract
Histology is part of the curricular base of all health courses, being the basis for understanding the composition of all tissues in the human body. Over the years, more and more technologies have entered the academic environment, with the aim of improving the teaching and learning process. Thus, the objective of this work was to conduct a systematic review on the use of digital technologies in teaching histology. The PICo strategy was used to develop the guiding question and the results were presented in a Prisma Flow. The following platforms were used to search for articles: PubMed, Embase. Web of Science, Science Direct, Medline, Scielo, Periódicos CAPES and LILACS, Open Gray and Google Scholar, with a time limit between 2012 and 2022. The results showed that this area is still little explored, with there not being a wide range of technologies being used and applied in teaching, with gamification and virtual microscopy being the most applied. However, it was realized that the use of these technologies can improve student performance and increase their interest in the subject. Therefore, these tools are great methods to reduce difficulties and encourage the development of a more receptive environment for the histology teaching and learning process., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
267. Biometric aspects of fruits and seeds and determination of the absorption curve of Hymenaea martiana Hayne seeds.
- Author
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Silva MJ, Alves EU, Silva JN, Silva RS, Bernardo MKF, Rodrigues CM, Pádua GVG, Silva JHCS, Silva MCL, Souza AG, and Smiderle OJ
- Subjects
- Seeds anatomy & histology, Fruit anatomy & histology, Biometry, Hymenaea anatomy & histology, Hymenaea classification, Hymenaea chemistry
- Abstract
The biometric differences between fruits and seeds are useful characteristics that can provide important data for the investigation and preservation of the species and may be linked to environmental and genetic influences. In this sense, considering the importance of this species and the need for conservation, the objective was to carry out physical characterization of the fruits and seeds of Hymenaea martiana as well as to determine the seed imbibition curve. The experiment was conducted at the Seed Analysis Laboratory at the Agricultural Sciences Center at the Federal University of Paraíba in Areia, PB. The evaluations carried out were as follows: biometry of fruits and seeds, number of seeds per fruit, colorimetry of fruits and seeds, percentage of damaged seeds, weight of a thousand seeds, seed water content, mass and imbibition curve. The biometric data were subjected to descriptive analysis to determine the minimum, maximum, average value, standard deviation, asymmetry, and kurtosis of the fruits and seeds. In terms of the biometric characteristics of the fruits and seeds of H. martiana, there was a marked variation, with average fruit lengths of 90.28 mm, widths of 46.83 mm, thicknesses of 34.69 mm, weights of 65.86 g and four seeds per fruit. The average length, width, thickness and weight of the seeds were 23.75 mm, 18.34 mm, 12.71 g and 4.13 g, respectively. The fruits were darker than the seeds, and both the fruits and seeds had red tones. Compared with nonscarified seeds, scarified seeds absorb a greater amount of water.
- Published
- 2024
- Full Text
- View/download PDF
268. Effects of cell concentration during cryopreservation on the post-thaw quality of Santa ines ram sperm.
- Author
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de Oliveira MB, Jeri Molina JC, da Silva RS, Ramos AF, Purdy PH, and Azevedo HC
- Subjects
- Female, Male, Sheep, Animals, Semen, Sperm Motility, Spermatozoa, Sheep, Domestic, Cryopreservation veterinary, Cryopreservation methods, Semen Preservation veterinary, Semen Preservation methods
- Abstract
Background: Non-surgical artificial insemination techniques for sheep may benefit from larger numbers of sperm in the insemination dose because the ewe cervix is convoluted and often cannot be traversed with an insemination gun resulting in deposition of the sperm at the os cervix., Objective: To compare a range of sperm concentrations when cryopreserving semen from Santa Ines rams and determine the effects of this on post-thaw quality., Materials and Methods: One ejaculate from each ram (n = 10) was diluted to four sperm concentrations to obtain the following groups: G-400, G-800, G-1200, and G-1600 x 10
6 sperm/mL. The semen samples were packaged in 0.25 mL straws, cooled to 5 degree C, cryopreserved in liquid nitrogen vapor, thawed in a water bath (40 degree C per 20 s), and were analyzed for computerized kinetics, capacitation and acrosome integrity, and plasma membrane integrity of sperm., Results: The G-400 treatment resulted in samples with the highest linearity and progressive motion (P < 0.05) and had significantly greater plasma membrane integrity, and lower capacitation and acrosome reaction rates compared to G-1600 (P < 0.05). Overall, use of the G-400 treatment resulted in better kinetics, less plasma membrane damage and less early capacitation. However, despite reducing the ejaculate yield and increasing the costs of the semen freezing process, the G-800 and G-1200 treatments make a greater absolute number of sperm with good kinetics, plasma membrane integrity and capacitation status available., Conclusion: Ram sperm concentration impacts cryopreservation, and higher concentrations may be advantageous if a single artificial insemination protocol is desirable. doi.org/10.54680/fr22610110812.- Published
- 2022
269. Positive relationships between insects and negative with spiders on Acacia auriculiformis (Fabaceae) plants in the savannah biome and their distribution pattern.
- Author
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Teixeira DL, Leite GLD, Silva LF, Veloso RVS, Silva RS, Guanabens PFS, Silva WM, Silva Junior ASP, Munhoz EJMM, Gomes JB, and Zanuncio JC
- Subjects
- Animals, Ecosystem, Insecta, Plants, Acacia, Ants, Arthropods, Fabaceae, Hemiptera, Spiders
- Abstract
Forest restoration is mainly based on plant-soil relationships and plant species with economic potential, but those between insects and other arthropods are also important to this reestablishment. The objective was to evaluate, during 24 months, the relationships between tending ants, Hemiptera phytophagous, predators and their distribution pattern (aggregated, random or uniform). The arthropods were sampled, stored and identified and their relationships and distribution patterns calculated with the BioDiversity-Pro software. The number of tending ants and phytophagous Hemiptera, Brachymyrmex sp. and Aethalion reticulatum, Cephalotes and Aleyrodidae were positively correlated. Tending ants were negatively correlated with Sternorrhyncha predators on A. auriculiformis saplings. The distribution of arthropods was aggregated, except for Teudis sp. and Cephalocoema sp., with a random pattern. The herbivores Stereoma anchoralis, Aethalion reticulatum and Tetragonisca angustula and the predators Brachymyrmex sp. and Dolichopodidae were the most abundant arthropods. The relationships between the arthropods studied on A. auriculiformis indicate that this plant, even introduced, is suitable for programs to recover degraded areas in the savannah.
- Published
- 2022
- Full Text
- View/download PDF
270. Free-feeding organisms and galling insects (Hymenoptera) interactions on Caryocar brasiliense (Malpighiales: Caryocaraceae) trees, a savanna plant from Brazil.
- Author
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Leite GLD, Soares MA, Veloso RVS, Silva LF, Guanabens PFS, Munhoz EJM, Pereira WR, Silva RS, Fernandes GW, Serrão JE, and Zanuncio JC
- Subjects
- Animals, Brazil, Ecosystem, Grassland, Humans, Insecta, Plants, Trees, Coleoptera, Hemiptera, Hymenoptera, Malpighiales, Mites
- Abstract
Galling insects are abundant in nature, found in many ecosystems globally, with species attacking plants of economic importance. We studied the effects of free-feeding organisms on the abundance of galling insects on Caryocar brasiliense (Caryocaraceae) trees in the Brazilian Cerrado (Savanna). Percentage of defoliation and the number of phytophagous mites or number of phytophagous Hemiptera correlated negatively with percentage of galled leaves and the parasitoid Eurytoma sp. (Hymenoptera: Eurytomidae) adults, respectively. Percentage of galled leaves and the numbers of Eurytoma sp. adults and phytophagous mites correlated positively with spiders. Numbers of mites and Hemiptera phytophagous correlated positively with those of lady beetles and Sycophila sp. (Hymenoptera: Eurytomidae), respectively. The number of Ablerus magistretti Blanchard (Hymenoptera: Aphelinidae) adults correlated negatively with Sycophila sp. The number of Agistemus sp. (Acari: Stigmaeidae) correlated, negatively and positively, with those of lady beetles and phytophagous mites, respectively. Free-feeding herbivores affected the presence of galling insects (Hymenoptera) on C. brasiliense trees, competing for food and space. The same was observed between two parasitoids of Eurytoma sp. galling insect, which can reduce the natural biological control of this pest.
- Published
- 2022
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- View/download PDF
271. Copaiba oil and Neem extract can be a potential alternative for the behavioral control of Sitophilus zeamais.
- Author
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Martins JC, Silva ÉM, Silva RS, Ferreira SR, and Picanço MC
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- Animals, Behavior Control, Melia chemistry, Insect Control, Insecticides pharmacology, Oils, Volatile pharmacology, Plant Extracts pharmacology, Weevils
- Abstract
Insects' ethology is an important factor when it is desired to carry out pest management. This knowledge makes it possible to manipulate behavioral activities, repel, or attract insects according to needs and interests. The maize weevil Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), one of the main stored grain pests, has been the target of studies of behavioral changes studies through natural substances due to its resistance to different insecticidal classes. Thus, this study aimed to evaluate the effect of sublethal concentrations of neem extract and copaiba oil on the locomotor behavior of S. zeamais. The behavioral characteristic considered were walking activity, the frequency of contact of insects with the treated grain mass, and the time spent for this behavior. The walking activity of the S. zeamais increased with exposure to Neem extract and Copaiba oil. In general, the Neem extract and Copaiba oil-induced more contact with grain mass than the control, suggesting an attractive effect on the insect, however more significant for the Neem oil. The insect's behavior was altered, presenting a specific path due to Copaiba oil and Neem extract stimuli. These results indicate that Copaiba oil and Neem extract can be a potential alternative for controlling S. zeamais on stored products since changes in this pests' behavior can reduce qualitative and quantitative grain damage. Thus, the development of products based on Copaiba oil and Neem extract may be helpful for storage pest management.
- Published
- 2022
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272. Sucking insects and their predators on tree canopies of a monocultural stand of Caryocar brasiliense.
- Author
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Demolin-Leite GL, Veloso RVS, Azevedo AM, Silva JL, Silva LF, Guanabens PFS, Gomes JB, Pereira WR, Silva RS, and Zanuncio JC
- Subjects
- Animals, Ecosystem, Humans, Insecta, Trees, Aphids, Malpighiales
- Abstract
Caryocar brasiliense Camb. (Malpighiales: Caryocaraceae) trees are widely distributed throughout the Cerrado ecosystem. The fruits of C. brasiliense trees are used by humans for food and as the main income source in many communities. C. brasiliense conservation is seriously threatened due to habitat loss caused by the land-use change. Sucking insects constitute an important ecological driver that potentially impact C. brasiliense survival in degraded environments. In addition, insects sampling methodologies for application in studies related to the conservation of C. brasiliense are poorly developed. In this study, sucking insects (Hemiptera) and their predators were recorded in three vertical strata of Caryocar brasiliense canopies. The distribution of sucking species showed vertical stratification along the canopy structure of C. brasiliense. The basal part of the canopy had the highest numbers of sucking insects Aphis gossypii (Glover 1877) (Hemiptera: Aphididae) and Bemisia tabaci (Genn. 1889) (Hemiptera: Aleyrodidae), and their predators Chrysoperla sp. (Neuroptera: Chrysopidae), spiders (Araneae), and Zelus armillatus (Lep. & Servi., 1825) (Hemiptera: Reduviidae). Predators' distribution follows the resource availability and preferred C. brasiliense tree parts with a higher abundance of prey.
- Published
- 2022
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- View/download PDF
273. Ecotoxicological effects of commercial herbicides on the reproductive system of aquatic arthropod Limnocoris submontandoni (Hemiptera: Naucoridae).
- Author
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Souza AM, Maciel JC, Barroso GM, Silva RS, Garraffoni ARS, Neves CA, Soares MA, and Santos JB
- Subjects
- Animals, Ecotoxicology, Genitalia, Arthropods, Hemiptera, Herbicides toxicity, Water Pollutants, Chemical toxicity
- Abstract
Worldwide, conventional agriculture makes extensive use of pesticides. Although the effects of herbicides are relatively well known in terms of environmental impacts on non-target organisms, there is very little scientific evidence regarding the impacts of herbicide residues on aquatic arthropods from tropical conservation areas. This study evaluates for the first time the toxicity of the herbicides ametryn, atrazine, and clomazone on the aquatic insect Limnocoris submontandoni (Hemiptera: Naucoridae). The lethal concentration (LC50) of herbicides was evaluated for these insects, as well as the effect of the herbicides on the insects' tissues and testicles. The estimated LC50 was 1012.41, 192.42, and 46.09 mg/L for clomazone, atrazine, and ametryn, respectively. Spermatocyte and spermatid changes were observed under the effect of atrazine, and effects on spermatogenesis were observed for some concentrations of clomazone, with apparent recovery after a short time. Our results provide useful information on the effects of herbicide residues in aquatic systems. This information can help minimize the risk of long-term reproductive effects in non-target species that have been previously overlooked in ecotoxicology studies.
- Published
- 2021
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- View/download PDF
274. First report of Palaeomystella tibouchinae Becker & Adamski, 2008 (Lepidoptera: Coleophoridae: Momphinae) in Rhynchanthera grandiflora (Melastomataceae) in Brazilian rupestrian fields of Espinhaço mountain range.
- Author
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Dos Santos JCB, da Cunha TG, Soares MA, Mendonça Filho CV, Araújo FHV, Ferreira SR, and Silva RS
- Subjects
- Animals, Brazil, Melastomataceae, Moths
- Published
- 2021
- Full Text
- View/download PDF
275. Pyometra-associated insulin resistance assessment by insulin binding assay and tyrosine kinase activity evaluation in canine muscle tissue.
- Author
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Pöppl ÁG, Valle SC, Mottin TS, Leal JS, González FHD, Kucharski LC, and Da Silva RSM
- Subjects
- Animals, Dogs, Female, Muscles metabolism, Phosphorylation, Protein-Tyrosine Kinases metabolism, Dog Diseases metabolism, Insulin Resistance, Insulins metabolism, Pyometra metabolism, Pyometra veterinary
- Abstract
Diestrus is associated with insulin resistance in bitches and pyometra can further impair insulin sensitivity. This study aimed to compare insulin sensitivity, insulin binding, and tyrosine kinase activity in bitches in anestrus, diestrus, or with pyometra. Patients submitted to elective ovariohysterectomy were divided into anestrus (n = 11) or diestrus (n = 13) according to reproductive history, vaginal cytology, and uterine histology. The group pyometra (n = 8) included bitches diagnosed with the disease based on clinical presentation and abdominal ultrasound findings and further confirmed by uterine histopathology. All patients were submitted to an intravenous glucose tolerance test (IVGTT) before ovariohysterectomy, and rectus abdominis muscle samples were collected during surgery for plasmatic membrane suspension preparation. Muscle-membranes were submitted to cold saturation insulin binding assay for dissociation constant (Kd) and maximum binding capacity (Bmax) determination, as well as exogenous substrate Poly (Glu: Tyr 4:1) phosphorylation assay for basal tyrosine kinase evaluation. Bitches with pyometra showed higher basal insulin (P < 0.001) and higher area under the curve (AUC) for insulin (P = 0.01) and glucose (P < 0.001) response during the IVGTT in comparison with bitches in anestrus or diestrus. Diestrus (P < 0.0001) and pyometra (P = 0.001) were associated with reduced tyrosine kinase activity in comparison with anestrus. No differences were documented in Kd and Bmax results for the low-affinity/high-capacity insulin receptors; however, high-affinity/low-capacity insulin receptors showed higher Kd and Bmax results in bitches in diestrus or with pyometra (P < 0.05) in comparison with anestrus. Despite the pyometra group showed the highest Kd values (P < 0.01), its Bmax results did not differ from the diestrus group (P > 0.05). Diestrus' higher Kd values and reduced tyrosine kinase activity in muscle tissue were compensated by increased total insulin binding capacity. Absent differences in IVGTT results between diestrus and anestrus bitches corroborate this finding. However, in bitches with pyometra, the highest Kd values were not compensated by increased total insulin binding capacity. This finding was associated with insulin resistance and glucose intolerance in IVGTT results. Moreover, pyometra resolution restored insulin sensitivity and glucose tolerance. These features can play a key role in pyometra-associated CDM, as well as in diabetic remission after pyometra resolution., (Copyright © 2021. Published by Elsevier Inc.)
- Published
- 2021
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276. First Report of Leptocybe invasa Fischer & LaSalle (Hymenoptera: Eulophidae) in the southern Tocantins, Brazil.
- Author
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Sarmento RA, Sarmento MI, da Silva RS, and Afonso R
- Subjects
- Animals, Brazil, Plant Tumors, Hymenoptera, Wasps
- Published
- 2021
- Full Text
- View/download PDF
277. First report of Chrysodeixis includens (Walker, [1858]) (Lepidotera: Noctuidae) in the dragon fruit (Hylocereus undatus) (Cactaceae).
- Author
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Jesus LM, Souza TAA, Silva RS, Araújo FHV, Picanço MC, and Martins JC
- Subjects
- Animals, Fruit, Cactaceae, Moths
- Published
- 2021
- Full Text
- View/download PDF
278. Distribution extension of Curimatella immaculata (Fernández-Yépez, 1948) Curimatidae, Amazon, Brazil.
- Author
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de Oliveira LP, Corrêa F, da Silva RS, and Vieira LJS
- Subjects
- Animals, Brazil, Rivers, Characiformes
- Published
- 2021
- Full Text
- View/download PDF
279. Viability of Staphylococcus aureus and expression of its toxins (SEC and TSST-1) in cheeses using Lactobacillus rhamnosus D1 or Weissella paramesenteroides GIR16L4 or both as starter cultures.
- Author
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Silva GO, Castro RD, Oliveira LG, Sant'Anna FM, Barbosa CD, Sandes SHC, Silva RS, Resende MFS, Lana AMQ, Nunes AC, Cerqueira MMOP, and Souza MR
- Subjects
- Animals, Bacterial Toxins genetics, Cheese analysis, Enterotoxins genetics, Food Microbiology, Lactobacillales metabolism, Lacticaseibacillus rhamnosus metabolism, Milk, Staphylococcus aureus genetics, Staphylococcus aureus metabolism, Superantigens genetics, Transcriptome, Weissella metabolism, Bacterial Toxins metabolism, Cheese microbiology, Enterotoxins metabolism, Lacticaseibacillus rhamnosus growth & development, Staphylococcus aureus growth & development, Superantigens metabolism, Weissella growth & development
- Abstract
Staphylococcus aureus is one of the main causative agents of food poisoning. This bacterium is an important component of cheese microbiota and plays an important role in foodborne diseases. Another important component of the microbiota is the lactic acid bacterium, which actively participates in processes that define the physicochemical, sensorial, and microbiological features of cheese. Of the various microbiological interactions in cheese, the interaction between lactic acid bacteria and Staph. aureus is most relevant. To this end, we evaluated the viability of Staph. aureus strains and the expression of their enterotoxins in cheeses produced experimentally, using Weissella paramesenteroides GIR16L4 or Lactobacillus rhamnosus D1 or both as starter cultures. Over 7 d, we observed that the presence of lactic acid bacteria did not impair Staph. aureus growth. However, via qPCR we observed a change in the gene expression of staphylococcal enterotoxins, suggesting that molecular communication exists between Staph. aureus strains and lactic acid bacteria in cheese., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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- View/download PDF
280. Renal developmental disturbances and their long-term consequences in female pups from vitamin D-deficient mothers: involved mechanisms.
- Author
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Almeida LF, Francescato HDC, Silva RS, Silva CGA, Antunes-Rodrigues J, de Paula FJA, and Coimbra TM
- Subjects
- Animals, Female, Kidney metabolism, Kidney pathology, Kidney Diseases metabolism, Kidney Diseases pathology, Maternal Nutritional Physiological Phenomena, Rats, Kidney blood supply, Kidney Diseases etiology, Vitamin D Deficiency complications
- Abstract
The mechanisms involved in kidney disturbances during development, induced by vitamin D3 deficiency in female rats, that persist into adulthood were evaluated in this study. Female offspring from mothers fed normal (control group, n=8) or vitamin D-deficient (Vit.D-, n=10) diets were used. Three-month-old rats had their systolic blood pressure (SBP) measured and their blood and urine sampled to quantify vitamin D3 (Vit.D3), creatinine, Na+, Ca+2 and angiotensin II (ANGII) levels. The kidneys were then removed for nitric oxide (NO) quantification and immunohistochemical studies. Vit.D- pups showed higher SBP and plasma ANGII levels in adulthood (P<0.05) as well as decreased urine osmolality associated with increases in urinary volume (P<0.05). Decreased expression of JG12 (renal cortex and glomeruli) and synaptopodin (glomeruli) as well as reduced renal NO was also observed (P<0.05). These findings showed that renal disturbances in development in pups from Vit.D- mothers observed in adulthood may be related to the development of angiogenesis, NO and ANGII alterations.
- Published
- 2019
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- View/download PDF
281. Natural factors regulating mustard aphid dynamics in cabbage.
- Author
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Fidelis EG, Farias ES, Silva RS, Lopes MC, Silva NR, and Picanço MC
- Subjects
- Animals, Aphids growth & development, Aphids parasitology, Brazil, Life Cycle Stages, Life Tables, Population Dynamics, Predatory Behavior, Aphids physiology, Brassica parasitology
- Abstract
Lipaphis erysimi (L.) Kaltenbach (Hemiptera: Aphididae) is one of the most important pests of brassica crops, mainly causing losses due to sap sucking, toxin injection and viral transmission. Knowledge about the main natural factors that regulate populations of this pest, as well as its critical mortality stage, is crucial for the development of integrated pest management of L. erysimi. Here, we determined the critical stage and key mortality factors for L. erysimi in cabbage using an ecological life table. Causes of mortality at each stage of L. erysimi development were monitored daily in the field for seven seasons. From the experimental data, we determined the key factor and critical stage of mortality through correlation and regression analyses. The nymphal stage, especially first instar nymphs, was critical for L. erysimi mortality. The key mortality factors were, in descending order of importance, physiological disturbances and predation by Syrphidae, Coccinellidae and Solenopsis ants. Therefore, control measures should target early stages of L. erysimi and the use of cabbage cultivars that have negative effects against L. erysimi may be a promising strategy for its management. Our results may be useful for plant geneticists who could develop new cabbage cultivars based on these findings. In addition, conservation measures of the main predators of L. erysimi may contribute to the natural control of this pest.
- Published
- 2019
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- View/download PDF
282. Evaluation of a Physical-Chemical Protocol for Porcine Tracheal Decellularization.
- Author
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Guimaraes AB, Correia AT, Alves BP, Da Silva RS, Martins JK, Pêgo-Fernandes PM, Xavier NS, Dolhnikoff M, and Cardoso PFG
- Subjects
- Animals, Male, Swine, Tissue Engineering methods, Tissue Scaffolds, Trachea cytology
- Abstract
Introduction/objective: Tracheal resection with primary reconstruction is the definitive treatment for many tracheal benign and malignant diseases. When primary resection is not deemed feasible as a result of the length of the stenosis, airway transplantation may become a solution. Tissue engineering offers an alternative way for creating tracheal substitutes. The development of tracheal allograft transplantation includes the decellularized tracheal scaffolds made of extracellular matrix that are seeded with the receptor's cells. Many protocols are used to obtain a decellularized scaffold. Most of them consist of cyclical physical-chemical steps with enzymes. This study proposes a protocol for decellularization based only in physical-chemical steps., Methods: Decellularization of pig tracheal segments was carried out using a standardized protocol consisting of freezing and thawing, 10 cycles of agitation, exposure to sodium deoxycholate, and washing. The degree of decellularization was determined by quantifying residual DNA. We also analyzed the morphology under hematoxylin and eosin staining., Results: Fourteen porcine tracheal segments were decellularized. All scaffolds obtained showed less than 2% of residual DNA (mean 20 ± 8 ng/mg) when compared to the fresh samples (mean 850 ± 123 ng/mg), P = .001. Morphological analysis showed that the epithelium and mixed glands were completely removed. It was possible to identify residual nuclei inside the cartilaginous rings (73.7 ± 12 × 26 ± 8 nuclei/field, P < .001)., Conclusion: The protocol tested was able to provide effective decellularization of porcine tracheas., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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- View/download PDF
283. Redox and metabolic strategies developed by anterior and posterior gills of the crab Neohelice granulata after short periods of hypo- or hyper-osmotic stress.
- Author
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Fernandes FA, Dutra BK, Mosele F, Araujo ASR, Ferreira GD, Belló-Klein A, Kucharski LC, Vinagre AS, and Da Silva RSM
- Subjects
- Animals, Gills, Hydrogen Peroxide, Oxidation-Reduction, Sodium-Potassium-Exchanging ATPase, Brachyura physiology, Osmotic Pressure, Stress, Physiological
- Abstract
The aim of this study was to identify the response pattern of redox balance, Na
+ /K+ ATPase activity and HSP70 expression in the posterior and anterior gills of the crab Neohelice granulata submitted to hypo- or hyper-osmotic stress for 1 h and 6 h. After 1 h of either type of osmotic stress, there was an increase in catalase activity, but a decrease in GSSG/GSH ratio (oxidized to reduced glutathione ratio) and Na+ /K+ ATPase activity in both gill sets. H2 O2 levels decreased only in the posterior gills. H2 O2 levels and Na+ /K+ ATPase activity remained reduced after 6 h of exposure to either type of osmotic stress in both gill sets. The GSSG/GSH ratio returned to initial levels after 6 h of hyper-osmotic stress, whereas it increased 10 times in both gill sets after hypo-osmotic stress. Furthermore, HSP70 protein expression increased in posterior gills after 6 h of hypo-osmotic stress. H2 O2 levels in tank water decreased after hypo-osmotic challenge and increased after 6 h of hyper-osmotic stress, indicating increased H2 O2 excretion. Therefore, N. granulata gills have redox, metabolic and molecular strategies to deal with rapid osmotic challenges, an important environmental parameter that influences juvenile and adult crab distribution and abundance within different populations., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
284. Insecticide toxicity to the borer Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae): developmental and egg-laying effects.
- Author
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Silva RS, Arcanjo LP, Soares JRS, Ferreira DO, Serrão JE, Martins JC, Costa ÁH, and Picanço MC
- Subjects
- Animals, Benzamides, Female, Hydrazines, Insect Control, Juvenile Hormones, Larva, Methomyl, Nitriles, Oviposition, Ovum, Oxazines, Pyrethrins, Solanum, Sulfones, Thiocarbamates, ortho-Aminobenzoates, Insecticides, Lepidoptera
- Abstract
Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) is one of the major pests of solanaceous plants in South America. It is considered a great threat by the European and Mediterranean Plant Protection Organization due to the serious economic damage that it causes on tomato farms; therefore, controlling this pest is a challenging task in South America. Controlling N. elegantalis at the egg stage is the best way to prevent it from damaging crops; however, thorough studies about the effectiveness of chemicals on the different life stages of this insect pest are lacking. In this study, the effects of different chemical classes were evaluated on N. elegantalis adults, female oviposition behavior, larvae, eggs, and embryonic development. None of the tested insecticides demonstrated toxicity to the adults; however, the results showed that cartap hydrochloride affects oviposition behavior. Moreover, methomyl and cartap hydrochloride exhibited high toxicity against the eggs and larvae, with higher than 80% of mortality. These insecticides interrupted larval hatching and caused alterations in the chorion layer. Flubendiamide and deltamethrin demonstrated toxicity on N. elegantalis larvae; however, lufenuron, indoxacarb, methoxyfenozide, and chlorantraniliprole demonstrated low toxicity on both eggs and larvae, with lower than 70% of mortality. Fruit treated with cartap hydrochloride had a deterrent effect. The ovicidal activity revealed by methomyl and cartap hydrochloride might provide new approaches regarding insecticide effects on eggs. Methomyl, cartap hydrochloride, flubendiamide, and deltamethrin demonstrated toxicity on larvae. The evaluation of the chorion of the eggshell in this study has clarified the toxic effect of methomyl and cartap hydrochloride on eggs.
- Published
- 2018
- Full Text
- View/download PDF
285. Temperature dependence of the nonlinear optical response of smectic liquid crystals containing gold nanorods.
- Author
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Silva RS, de Melo PB, Omena L, Nunes AM, da Silva MGA, Meneghetti MR, and de Oliveira IN
- Abstract
The present study is devoted to the investigation of the nonlinear optical properties of a smectic liquid crystal doped with gold nanorods. Using the Z-scan technique, we investigate the changes in the optical birefringence of a homeotropic sample upon laser exposure, considering the configurations of normal and oblique incidence. Our results reveal that the birefringence variations may be governed by distinct physical mechanisms, depending on the relative angle between the far-field director and the wave vector of the excitation laser beam. In particular, we observe that the position dependence of the far-field transmittance exhibits different behaviors as the incidence angle is changed, indicating that distortions in the beam wavefront may be associated with the thermal lens phenomenon or an optically induced reorientation of the nematic director. The temperature dependence of the nonlinear refractive and absorptive coefficients is investigated close to the smectic-A-nematic phase transition. A detailed analysis of the interplay between smectic order and plasmon resonance is performed, thus unveiling the capability of plasmonic liquid crystal to be used in optical devices.
- Published
- 2017
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286. Glyceroneogenesis in the hepatopancreas of the crab Neohelice granulata: Diet, starvation and season effects.
- Author
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Sarapio E, Santos JT, Model JFA, De Fraga LS, Vinagre AS, Martins TL, Da Silva RSM, and Trapp M
- Subjects
- Animals, Dietary Carbohydrates metabolism, Dietary Proteins metabolism, Fatty Acids metabolism, Seasons, Brachyura metabolism, Diet, Gluconeogenesis physiology, Glucose metabolism, Glycerol metabolism, Hepatopancreas metabolism, Starvation
- Abstract
We determined the activity of glyceroneogenesis from [2-
14 C]-pyruvate, the phosphoenolpyruvate carboxykinase activity, [2-14 C]-pyruvate oxidation and total lipid levels in the hepatopancreas of the crab Neohelice granulata fed with a carbohydrate-rich (HC) diet or a high-protein (HP) diet and then subjected to 5weeks of starvation, in summer and winter, to determine whether the seasonal adjustments of lipid metabolism to food scarcity are modulated by the composition of the diet previously given to the crabs. The results demonstrated that glyceroneogenesis is an active pathway in N. granulata hepatopancreas, and is regulated by seasonal variations, diet composition and starvation. This study showed that in summer the increase in the hepatopancreas glyceroneogenesis activity is among the strategies used by N. granulata fed an HP diet, to maintain the triglyceride/fatty acid cycle during starvation, a normal condition in the biological cycle of this crab. However, the administration of an HC diet reduced the glyceroneogenesis capacity in response to starvation in summer. In winter, the decrease in the glyceroneogenesis capacity in both fed (HP and HC diets) and starved crabs seems to be a strategy to reduce energy consumption and/or requirement. In contrast to the summer results, the incorporation of [2-14 C]-pyruvate into14 CO2 was markedly higher in both diet (HC and HP) groups and in starved crabs during the winter. Four decades after the first study describing the glyceroneogenesis pathway in rat white adipose tissue, this pathway is evidenced for the first time in a crustacean., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2017
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- View/download PDF
287. The characterization of Bordetella pertussis strains isolated in the Central-Western region of Brazil suggests the selection of a specific genetic profile during 2012-2014 outbreaks.
- Author
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Rocha EL, Leite D, Camargo CH, Martins LM, Silva RSN, Martins VP, and Campos TA
- Subjects
- Brazil epidemiology, Electrophoresis, Gel, Pulsed-Field, Humans, Infant, Infant, Newborn, Prevalence, Serogroup, Serotyping, Whooping Cough microbiology, Bordetella pertussis genetics, Disease Outbreaks, Genotype, Whooping Cough epidemiology
- Abstract
Pertussis is a worldwide acute respiratory disease caused by the bacterium Bordetella pertussis. Despite high vaccine coverage, the bacterium continues to circulate in populations and is still one of the most common vaccine-preventable diseases. In Brazil, pertussis incidence has presented a significant decrease since 1990 but since 2011 a sudden increase in incidence has been observed. Thus, the aim of this study was to perform a molecular epidemiological characterization of B. pertussis strains isolated in the Central-Western region (specifically in Distrito Federal) of Brazil from August 2012 to August 2014. During this period, 92 B. pertussis strains were isolated from the outbreaks. All strains were characterized by serotyping and XbaI pulsed-field gel electrophoresis profiles. From August to December 2012, the most prevalent serotype observed was 1,3 (13/17). During 2013 the prevalence of serotype 1,3 decreased (13/30) and from January 2014 to August 2014 the most prevalent serotype was 1,2 (33/45). Fourteen PFGE profiles were identified. Of these, BP-XbaI0039 prevalence increased from 3/17 in 2012 to 10/30 in 2013, and 35/45 in 2014. These results evidence the selection of a specific genetic profile during this period, suggesting the occurrence of a bacterial genomic profile with high circulation potential.
- Published
- 2017
- Full Text
- View/download PDF
288. Selection of morphoagronomic descriptors for the characterization of accessions of cassava of the Eastern Brazilian Amazon.
- Author
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Silva RS, Moura EF, Farias-Neto JT, Ledo CA, and Sampaio JE
- Subjects
- Brazil, Crops, Agricultural growth & development, Manihot growth & development, Models, Genetic, Crops, Agricultural genetics, Manihot genetics, Quantitative Trait, Heritable
- Abstract
The aim of this study was to select morphoagronomic descriptors to characterize cassava accessions representative of Eastern Brazilian Amazonia. It was characterized 262 accessions using 21 qualitative descriptors. The multiple-correspondence analysis (MCA) technique was applied using the criteria: contribution of the descriptor in the last factorial axis of analysis in successive cycles (SMCA); reverse order of the descriptor's contribution in the last factorial axis of analysis with all descriptors ('O'´p') of Jolliffe's method; mean of the contribution orders of the descriptor in the first three factorial axes in the analysis with all descriptors ('Os') together with ('O'´p'); and order of contribution of weighted mean in the first three factorial axes in the analysis of all descriptors ('Oz'). The dissimilarity coefficient was measured by the method of multicategorical variables. The correlation among the matrix generated with all descriptors and matrices based on each criteria varied (r = 0.21, r = 0.97, r = 0.98, r = 0.13 for SMCA, 'Os', 'Oz' and 'O'´p', respectively). The least informative descriptors were discarded independently and according to both 'Os' and 'Oz' criteria. Thirteen descriptors were capable to discriminate the accessions and to represent the morphological variability of accessions sampled in Brazilian Eastern Amazonia: color of apical leaves, petiole color, color of stem exterior, external color of storage root, color of stem cortex, color of root pulp, texture of root epidermis, color of leaf vein, color of stem epidermis, color of end branches of adult plant, branching habit, root shape, and constriction of root.
- Published
- 2017
- Full Text
- View/download PDF
289. Correlation and path analysis of biomass sorghum production.
- Author
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Vendruscolo TP, Barelli MA, Castrillon MA, da Silva RS, de Oliveira FT, Corrêa CL, Zago BW, and Tardin FD
- Subjects
- Environment, Genetic Variation, Genotype, Phenotype, Quantitative Trait, Heritable, Biomass, Sorghum genetics
- Abstract
Sorghum biomass is an interesting raw material for bioenergy production due to its versatility, potential of being a renewable energy source, and low-cost of production. The objective of this study was to evaluate the genetic variability of biomass sorghum genotypes and to estimate genotypic, phenotypic, and environmental correlations, and direct and indirect effects of seven agronomic traits through path analysis. Thirty-four biomass sorghum genotypes and two forage sorghum genotypes were cultivated in a randomized block design with three replicates. The following morpho-agronomic traits were evaluated: flowering date, stem diameter, number of stems, plant height, number of leaves, green mass production, and dry matter production. There were significant differences at the 1% level for all traits. The highest genotypic correlation was found between the traits green mass production and dry matter production. The path analysis demonstrated that green mass production and number of leaves can assist in the selection of dry matter production.
- Published
- 2016
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290. Photocytotoxicity of a cyanine dye with two chromophores toward melanoma and normal cells.
- Author
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Murakami LS, Ferreira LP, Santos JS, da Silva RS, Nomizo A, Kuz'min VA, and Borissevitch IE
- Subjects
- Animals, Carbocyanines metabolism, Cell Survival drug effects, Dose-Response Relationship, Drug, Fluorescent Dyes metabolism, Hematoporphyrins metabolism, Humans, Inhibitory Concentration 50, Melanoma, Experimental metabolism, Mice, Permeability, Photosensitizing Agents metabolism, Time Factors, Carbocyanines pharmacology, Fluorescent Dyes pharmacology, Hematoporphyrins pharmacology, Melanoma, Experimental pathology, Photochemotherapy methods, Photosensitizing Agents pharmacology
- Abstract
Background: Due to high optical absorption, triplet quantum yield and affinity to biological structures bichromophoric cyanine dyes (BCDs) can be considered promising sensitizers for application in photodynamic therapy (PDT). In this work, we report on the study of the BCD photocytotoxicity toward melanoma and normal cells in comparison with that of commercial photosensitizer Photogem®., Methods: The cytotoxic and phototoxic effects were measured by standard tests of cell viability. The drug uptake was obtained by the flow cytometry and optical absorption techniques. The BCD intracellular distribution was obtained by the fluorescence image microscopy using specific organelle markers., Results: Both drugs demonstrated increased cytotoxicity under irradiation, while in darkness their cytotoxic effect at concentrations lower than 20 μM after 24 h of incubation did not exceed 20%. For 5 h of incubation, BCD photocytotoxicity in relation to melanoma cells reached 100% already at concentrations below 5 μM, while for normal cells the effect did not exceed 70% even for the 20 μM concentration. It is shown that BCD penetrates into the cells and is located predominantly in perinuclear cytoplasmic structures., Conclusions: The BCD photosensitizing characteristics appear more adequate for application in PDT than that of the actually applied commercial photosensitizer Photogem®. Higher light absorption by BCD in the near IR region and its preferential localization in mitochondria can explain its high photocytotoxicity., General Significance: BCD can be considered as a new promising photosensitizer class for cancer PDT., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2015
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291. FSH up-regulates angiogenic factors in luteal cells of buffaloes.
- Author
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Fátima LA, Evangelista MC, Silva RS, Cardoso AP, Baruselli PS, and Papa PC
- Subjects
- Angiogenic Proteins analysis, Animals, Cells, Cultured, Female, Fibroblast Growth Factor 2 analysis, Fibroblast Growth Factor 2 genetics, Fluorescent Antibody Technique, Granulosa Cells chemistry, Granulosa Cells drug effects, Granulosa Cells metabolism, Luteal Cells chemistry, Luteinizing Hormone pharmacology, Male, Progesterone biosynthesis, RNA, Messenger analysis, Real-Time Polymerase Chain Reaction veterinary, Receptor, Fibroblast Growth Factor, Type 2 analysis, Receptor, Fibroblast Growth Factor, Type 2 genetics, Receptor, Fibroblast Growth Factor, Type 3 analysis, Receptor, Fibroblast Growth Factor, Type 3 genetics, Superovulation physiology, Up-Regulation, Vascular Endothelial Growth Factor A analysis, Vascular Endothelial Growth Factor A genetics, Angiogenic Proteins genetics, Buffaloes metabolism, Follicle Stimulating Hormone pharmacology, Luteal Cells metabolism
- Abstract
Follicle-stimulating hormone has been widely used to induce superovulation in buffaloes and cows and usually triggers functional and morphologic alterations in the corpus luteum (CL). Several studies have shown that FSH is involved in regulating vascular development and that adequate angiogenesis is essential for normal luteal development. Angiogenesis is regulated by many growth factors, of which vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2) have an established central role. Therefore, we have used a combination of in vitro and in vivo studies to assess the effects of FSH on the expression of VEGF and FGF2 and their receptors in buffalo luteal cells. The in vivo model consisted of 12 buffalo cows, divided into control (n = 6) and superovulated (n = 6) groups, and CL samples were collected on day 6 after ovulation. In this model, we analyzed the gene and protein expression of FGF2 and its receptors and the protein expression of VEGFA systems with the use of real-time PCR, Western blot analysis, and immunohistochemistry. In the in vitro model, granulosa cells were collected from small follicles (diameter, 4-6 mm) of buffaloes and cultured for 4 d in serum-free medium with or without FSH (10 ng/mL). To induce in vitro luteinization, LH (250 ng/mL) and fetal bovine serum (10%) were added to the medium, and granulosa cells were maintained in culture for 4 d more. The progesterone concentration in the medium was measured at days 4, 5, and 8 after the beginning of cell culture. Cells were collected at day 8 and subjected to real-time PCR, Western blot analysis, and immunofluorescence for assessment of the expression of FGF2, VEGF, and their receptors. To address the percentage of steroidogenic and growth factor-expressing cells in the culture, flow cytometry was performed. We observed that in superovulated buffalo CL, the FGF2 system mRNA expression was decreased even as protein expression was increased and that the VEGF protein was increased (P < 0.05). In vitro experiments with granulosa cells showed an increase in the mRNA expression of VEGF and FGF2 and its receptors 1 and 2 and protein expression of VEGF, kinase insert domain receptor, FGF receptor 2, and FGF receptor 3 in cells treated with FSH (P < 0.05), in contrast to the in vivo experiments. Moreover, the progesterone production by FSH-treated cells was elevated compared with untreated cells (P < 0.05). Our findings indicate that VEGF, FGF2, and their receptors were differentially regulated by FSH in vitro and in vivo in buffalo luteal cells, which points toward a role of CL environment in modulating cellular answers to gonadotropins., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
292. Profile of nucleotide catabolism and ectonucleotidase expression from the hippocampi of neonatal rats after caffeine exposure.
- Author
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Da Silva RS, Richetti SK, Tonial EM, Bogo MR, and Bonan CD
- Subjects
- Animals, Animals, Newborn, Base Sequence, DNA Primers, Female, Hippocampus enzymology, Rats, Rats, Wistar, Reverse Transcriptase Polymerase Chain Reaction, Caffeine administration & dosage, Hippocampus metabolism, Nucleotidases metabolism, Nucleotides metabolism
- Abstract
Nucleotides and nucleosides play an important role in neurodevelopment acting through specific receptors. Ectonucleotidases are the major enzymes involved in controlling the availability of purinergic receptors ligands. ATP is co-released with several neurotransmitters and is the most important source of extracellular adenosine by catabolism exerted by ectonucleotidases. The main ectonucleotidases are named NTPDases (1-8) and 5'-nucleotidase. Adenosine is a powerful modulator of neurotransmitter release. Caffeine blocks adenosine receptor activity as well as adenosine-mediated neuromodulation. Considering the susceptibility of the immature brain to caffeine and the need for correct purinergic signaling during fetal development, we have analyzed the effects of caffeine exposure during gestational and lactational periods on nucleotide degradation and ectonucleotidase expression from the hippocampi of 7-, 14- and 21-days-old rats. Nucleotides hydrolysis was assessed by colorimetric determination of inorganic phosphate released. Ectonucleotidases expression was performed by RT-PCR. ATP and ADP hydrolysis displayed parallel age-dependent decreases in both control and caffeine-treated groups. AMP hydrolysis increased with caffeine treatment in 7-days-old rats (75%); although there was no significant difference in AMP hydrolysis between control (non caffeine-treated) rats and 14- or 21-days caffeine-treated rats. ADP hydrolysis was not affected by caffeine treatment. Caffeine treatment in 7- and 14-days-old rats decreased ATP hydrolysis when compared to the control group (19% and 60% decrease, respectively), but 21-days-treated rats showed an increase in ATP hydrolysis (39%). Expression levels of NTPDase 1 and 5 decreased in hippocampi of caffeine-treated rats. The expression of 5'-nucleotidase was not affected after caffeine exposure. The changes observed in nucleotide hydrolysis and ectonucleotidases expression could promote subtle effects on normal neural development considering the neuromodulatory role of adenosine.
- Published
- 2012
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293. [Attitudes of nurses towards families: validation of the scale Families' Importance in Nursing Care--Nurses Attitudes].
- Author
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Oliveira Pda C, Fernandes HI, Vilar AI, Figueiredo MH, Ferreira MM, Martinho MJ, Figueiredo Mdo C, Andrade LM, de Carvalho JC, and Martins MM
- Subjects
- Cultural Characteristics, Humans, Attitude of Health Personnel, Family Nursing, Professional-Family Relations, Surveys and Questionnaires
- Abstract
The attitudes of nurses towards families determine the care process. With this study, we aimed to obtain an instrument that would allow us to learn about this variable. Hence, our purpose was to perform the cross-cultural adaptation and evaluate the psychometric features of the Portuguese version of the instrument Families' Importance in Nursing Care - Nurses Attitudes (FINC-NA), which aims to evaluate the attitudes of nurses towards the importance of involving the patient's family in the nursing care. The method recommended by the literature was followed. The sample consisted of 136 nurses working in primary health care. The results obtained in the reliability tests showed good internal consistency (Cronbach's Alpha=0.87). The psychometric study permits us to state that the Portuguese version of the FINC-NA, which in Portuguese is referred to as A importância das famílias nos cuidados de enfermagem - atitudes dos enfermeiros (IFCE-AE), is a reliable and valid tool.
- Published
- 2011
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294. Economic injury level for the coffee berry borer (Coleoptera: Curculionidae: Scolytinae) using attractive traps in Brazilian coffee fields.
- Author
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Fernandes FL, Picanço MC, Campos SO, Bastos CS, Chediak M, Guedes RN, and Silva RS
- Subjects
- Animals, Benzoic Acid pharmacology, Brazil, Coffee, Ethanol pharmacology, Female, Insect Control economics, Methanol pharmacology, Population Density, Sample Size, Sampling Studies, Seasons, Coleoptera drug effects, Crops, Agricultural economics, Insect Control methods, Pheromones pharmacology
- Abstract
The currently existing sample procedures available for decision-making regarding the control of the coffee berry borer Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) are time-consuming, expensive, and difficult to perform, compromising their adoption. In addition, the damage functions incorporated in such decision levels only consider the quantitative losses, while dismissing the qualitative losses. Traps containing ethanol, methanol, and benzaldehyde may allow cheap and easy decision-making. Our objective was to determine the economic injury level (EIL) for the adults of the coffee berry borer by using attractant-baited traps. We considered both qualitative and quantitative losses caused by the coffee borer in estimating the EILs. These EILs were determined for conventional and organic coffee under high and average plant yield. When the quantitative losses caused by H. hampei were considered alone, the EILs ranged from 7.9 to 23.7% of bored berries for high and average-yield conventional crops, respectively. For high and average-yield organic coffee the ELs varied from 24.4 to 47.6% of bored berries, respectively. When qualitative and quantitative losses caused by the pest were considered together, the EIL was 4.3% of bored berries for both conventional and organic coffee. The EILs for H. hampei associated to the coffee plants in the flowering, pinhead fruit, and ripening fruit stages were 426, 85, and 28 adults per attractive trap, respectively.
- Published
- 2011
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295. Zebrafish neurotransmitter systems as potential pharmacological and toxicological targets.
- Author
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Rico EP, Rosemberg DB, Seibt KJ, Capiotti KM, Da Silva RS, and Bonan CD
- Subjects
- Animals, Behavior, Animal drug effects, Central Nervous System metabolism, Synaptic Transmission drug effects, Central Nervous System drug effects, Models, Animal, Neurotransmitter Agents metabolism, Pharmacology methods, Toxicology methods, Zebrafish metabolism
- Abstract
Recent advances in neurobiology have emphasized the study of brain structure and function and its association with numerous pathological and toxicological events. Neurotransmitters are substances that relay, amplify, and modulate electrical signals between neurons and other cells. Neurotransmitter signaling mediates rapid intercellular communication by interacting with cell surface receptors, activating second messenger systems and regulating the activity of ion channels. Changes in the functional balance of neurotransmitters have been implicated in the failure of central nervous system function. In addition, abnormalities in neurotransmitter production or functioning can be induced by several toxicological compounds, many of which are found in the environment. The zebrafish has been increasingly used as an animal model for biomedical research, primarily due to its genetic tractability and ease of maintenance. These features make this species a versatile tool for pre-clinical drug discovery and toxicological investigations. Here, we present a review regarding the role of different excitatory and inhibitory neurotransmitter systems in zebrafish, such as dopaminergic, serotoninergic, cholinergic, purinergic, histaminergic, nitrergic, glutamatergic, glycinergic, and GABAergic systems, and emphasizing their features as pharmacological and toxicological targets. The increase in the global knowledge of neurotransmitter systems in zebrafish and the elucidation of their pharmacological and toxicological aspects may lead to new strategies and appropriate research priorities to offer insights for biomedical and environmental research., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
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296. Mechanisms underlying the vascular relaxation induced by a new nitric oxide generator.
- Author
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Rodrigues GJ, Cicillini SA, Silva RS, and Bendhack LM
- Subjects
- Animals, Aorta cytology, Aorta drug effects, Calcium metabolism, Dose-Response Relationship, Drug, Endothelium, Vascular metabolism, Male, Muscle, Smooth, Vascular metabolism, Nitric Oxide chemistry, Organometallic Compounds chemical synthesis, Organometallic Compounds chemistry, Rats, Rats, Wistar, Endothelium, Vascular drug effects, Muscle, Smooth, Vascular drug effects, Nitric Oxide biosynthesis, Organometallic Compounds pharmacology, Vasodilation drug effects
- Abstract
Nitric oxide (NO) is a potent vasodilator and it can be generated by the ruthenium complex cis-[Ru(H-dcbpy(-))(2)(Cl)(NO(2)(-))] (DCBPY). The present study aimed to investigate the NO specie generated and to characterize the cellular mechanisms involved on the vasodilatation induced by DCBPY. It was found that at pH 7.4 and 9.4, the NO(+) coordinated to ruthenium (Ru-NO(+)) is converted to NO(2)(-) (Ru-NO(2)(-)), which remains stable. However, the configuration Ru-NO(+) is stable at pH 5.4. It was also verified that the DCBPY complex (Ru-NO(2)(-) configuration) induces vascular relaxation of contracted rat aortic rings in a concentration-dependent manner. Therefore, the potency (pD(2) values) and the maximum relaxant effect (ME) were compared. It was observed that relaxation is more pronounced to Ru-NO(+) configuration, compared with Ru-NO(2)(-), with no difference in ME. On the other hand, the potency of DCBPY (Ru-NO(2)(-)) is lower than that of SNP and higher than that of NITRITE, with no difference in ME for all the compounds. Further experiments were conducted using DCBPY in the Ru-NO(2)(-) configuration. It was noted that the relaxation induced by DCBPY is completely blocked by the soluble guanylyl cyclase (sGC) enzyme inhibitor. The non-selective K(+) channel blocker (TEA) diminishes the potency of DCBPY, but it does not change the ME. Incubation with selective radicalar NO (NO()) and extracellular NO scavengers almost abolishes the relaxation induced by DCBPY. The use of a selective nitroxyl (NO(-)) scavenger decreases the potency of DCBPY, but it does not alter the ME. By using confocal microsopy, it was found that DCBPY, SNP, and NITRITE raise the cytosolic NO concentration and reduce the cytosolic Ca(2+) concentration [Ca(2+)]c in rat aortic smooth muscle cells. These effects are not different when DCBPY and SNP are compared, but they are lower for NITRITE. Taken together, our results demonstrate that the compound DCBPY (Ru-NO(2)(-)) is an NO generator that promotes relaxation of rat aortic rings due to a reduction in [Ca(2+)]c. The vascular smooth muscle relaxation is dependent on sGC activation., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
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297. Sleep, ageing and night work.
- Author
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Pires ML, Teixeira CW, Esteves AM, Bittencourt LR, Silva RS, Santos RF, Tufik S, and Mello MT
- Subjects
- Adult, Age Factors, Aged, Brazil, Humans, Male, Middle Aged, Polysomnography, Sleep Disorders, Circadian Rhythm diagnosis, Surveys and Questionnaires, Automobile Driving, Sleep Disorders, Circadian Rhythm etiology, Task Performance and Analysis, Work Schedule Tolerance
- Abstract
Studies have shown that the frequency or worsening of sleep disorders tends to increase with age and that the ability to perform circadian adjustments tends to decrease in individuals who work the night shift. This condition can cause consequences such as excessive sleepiness, which are often a factor in accidents that occur at work. The present study investigated the effects of age on the daytime and nighttime sleep patterns using polysomnography (PSG) of long-haul bus drivers working fixed night or day shifts. A total of 124 drivers, free of sleep disorders and grouped according to age (<45 years, N = 85, and > or =45 years, N = 39) and PSG timing (daytime (D) PSG, N = 60; nighttime (N) PSG, N = 64) participated in the study. We observed a significant effect of bedtime (D vs N) and found that the length of daytime sleep was shorter [D: <45 years (336.10 +/- 73.75 min) vs N: <45 years (398 +/- 78.79 min) and D: > or =45 years (346.57 +/- 43.17 min) vs N: > or =45 years (386.44 +/- 52.92 min); P < or = 0.05]. Daytime sleep was less efficient compared to nighttime sleep [D: <45 years (78.86 +/- 13.30%) vs N: <45 years (86.45 +/- 9.77%) and D: > or =45 years (79.89 +/- 9.45%) and N: > or =45 years (83.13 +/- 9.13%); P < or = 0.05]. An effect of age was observed for rapid eye movement sleep [D: <45 years (18.05 +/- 6.12%) vs D: > or =45 years (15.48 +/- 7.11%) and N: <45 years (23.88 +/- 6.75%) vs N: > or =45 years (20.77 +/- 5.64%); P < or = 0.05], which was greater in younger drivers. These findings are inconsistent with the notion that older night workers are more adversely affected than younger night workers by the challenge of attempting to rest during the day.
- Published
- 2009
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298. New nitric oxide donors based on ruthenium complexes.
- Author
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Lunardi CN, da Silva RS, and Bendhack LM
- Subjects
- Animals, Aorta drug effects, Calcium Channels drug effects, Calcium Channels physiology, Cyclic GMP-Dependent Protein Kinases metabolism, Hypertension, Renal physiopathology, Muscle Relaxation, Muscle, Smooth, Vascular enzymology, Muscle, Smooth, Vascular physiopathology, Nitric Oxide metabolism, Potassium Channels drug effects, Potassium Channels physiology, Rats, Ruthenium chemistry, Signal Transduction drug effects, Time Factors, Vasodilation drug effects, Vasodilation physiology, Cyclic GMP-Dependent Protein Kinases drug effects, Muscle, Smooth, Vascular drug effects, Nitric Oxide Donors pharmacology, Ruthenium pharmacology
- Abstract
Nitric oxide (NO) donors produce NO-related activity when applied to biological systems. Among its diverse functions, NO has been implicated in vascular smooth muscle relaxation. Despite the great importance of NO in biological systems, its pharmacological and physiological studies have been limited due to its high reactivity and short half-life. In this review we will focus on our recent investigations of nitrosyl ruthenium complexes as NO-delivery agents and their effects on vascular smooth muscle cell relaxation. The high affinity of ruthenium for NO is a marked feature of its chemistry. The main signaling pathway responsible for the vascular relaxation induced by NO involves the activation of soluble guanylyl-cyclase, with subsequent accumulation of cGMP and activation of cGMP-dependent protein kinase. This in turn can activate several proteins such as K+ channels as well as induce vasodilatation by a decrease in cytosolic Ca2+. Oxidative stress and associated oxidative damage are mediators of vascular damage in several cardiovascular diseases, including hypertension. The increased production of the superoxide anion (O2-) by the vascular wall has been observed in different animal models of hypertension. Vascular relaxation to the endogenous NO-related response or to NO released from NO deliverers is impaired in vessels from renal hypertensive (2K-1C) rats. A growing amount of evidence supports the possibility that increased NO inactivation by excess O2- may account for the decreased NO bioavailability and vascular dysfunction in hypertension.
- Published
- 2009
- Full Text
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299. Relationship between Brazilian airline pilot errors and time of day.
- Author
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de Mello MT, Esteves AM, Pires ML, Santos DC, Bittencourt LR, Silva RS, and Tufik S
- Subjects
- Accidents, Aviation, Brazil, Humans, Research Design, Aerospace Medicine statistics & numerical data, Arousal physiology, Circadian Rhythm physiology, Fatigue
- Abstract
Flight safety is one of the most important and frequently discussed issues in aviation. Recent accident inquiries have raised questions as to how the work of flight crews is organized and the extent to which these conditions may have been contributing factors to accidents. Fatigue is based on physiologic limitations, which are reflected in performance deficits. The purpose of the present study was to provide an analysis of the periods of the day in which pilots working for a commercial airline presented major errors. Errors made by 515 captains and 472 co-pilots were analyzed using data from flight operation quality assurance systems. To analyze the times of day (shifts) during which incidents occurred, we divided the light-dark cycle (24:00) in four periods: morning, afternoon, night, and early morning. The differences of risk during the day were reported as the ratio of morning to afternoon, morning to night and morning to early morning error rates. For the purposes of this research, level 3 events alone were taken into account, since these were the most serious in which company operational limits were exceeded or when established procedures were not followed. According to airline flight schedules, 35% of flights take place in the morning period, 32% in the afternoon, 26% at night, and 7% in the early morning. Data showed that the risk of errors increased by almost 50% in the early morning relative to the morning period (ratio of 1:1.46). For the period of the afternoon, the ratio was 1:1.04 and for the night a ratio of 1:1.05 was found. These results showed that the period of the early morning represented a greater risk of attention problems and fatigue.
- Published
- 2008
- Full Text
- View/download PDF
300. Effect of smoking habits on sleep.
- Author
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Conway SG, Roizenblatt SS, Palombini L, Castro LS, Bittencourt LR, Silva RS, and Tufik S
- Subjects
- Adult, Aged, Body Mass Index, Case-Control Studies, Female, Humans, Male, Middle Aged, Oxyhemoglobins metabolism, Polysomnography, Regression Analysis, Sleep Apnea Syndromes diagnosis, Sleep Apnea Syndromes physiopathology, Sleep Initiation and Maintenance Disorders diagnosis, Sleep Initiation and Maintenance Disorders physiopathology, Time Factors, Sleep Apnea Syndromes etiology, Sleep Initiation and Maintenance Disorders etiology, Smoking adverse effects
- Abstract
To evaluate the effect of smoking habits on sleep, data from 1492 adults referred to the Sleep Institute were accessed and divided into 3 categories of smoking status: current, former and non-smokers. Categories of pack-years (<15 and > or =15) defined smoking severity. The association of smoking status and smoking severity with sleep was analyzed for sleep parameters, especially apnea and hypopnea index (AHI) > or =5, more than 5% of total sleep time (TST) spent with oxyhemoglobin saturation (SaO2) <90%, and arousal index. The arousal index was higher among current (21 +/- 17) and former smokers (20 +/- 17) than non-smokers (17 +/- 15; P < 0.04). Former smokers had a higher percent of TST at SaO2 <90% than non-smokers (9 +/- 18 vs 6 +/- 13; P < 0.04). Former smokers with pack-years > or =15 compared to <15 exhibited higher AHI (22 +/- 24 vs 16 +/- 21; P < 0.05) and arousal index (22 +/- 19 vs 18 +/- 15; P < 0.05). Current smokers with pack-years > or =15 compared to <15 exhibited higher arousal index (23 +/- 18 vs 18 +/- 16; P < 0.05) and percent of TST at SaO2 <90% (11 +/- 17 vs 6 +/- 13; P < 0.05). Smoking status and pack-years were not associated with AHI > or =5 on logistic regression analysis, but current smokers with pack-years > or =15 were 1.9 times more likely to spend more than 5% of TST at SaO2 <90% than non-smokers (95%CI = 1.21-2.97; P = 0.005). The variability of arousal index was influenced by gender, AHI and current smokers with pack-years > or =15 (all P < 0.01). Smoking habits seem to be associated with arousal and oxyhemoglobin desaturation during sleep, but not with AHI. The effect was more pronounced in current than former smokers.
- Published
- 2008
- Full Text
- View/download PDF
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