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1.
Appl Radiat Isot ; 184: 110177, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35272230

RESUMO

Flexible pipes are modular constructions made up of several layers. They are broadly employed in oil & gas industry, playing an important role in the Brazilian Pre-Salt production. Under specific conditions, seawater can ingress and this contact with metallic middle layers can significantly lead to a service life reduction of these layers, especially due to a mechanism known as CO2 Stress Corrosion Cracking (SCC-CO2). Therefore, it becomes mandatory that inspection systems suitable for submarine use in order to detect annulus flooding before the failure of the flexible pipe become available. This paper presents an inspection system based on the gamma rays transmission focused on detecting such flood condition, possibly overcoming limitations of other inspection systems available in the market. The reliability of this solution was statistically evaluated as presented herein, showing great robustness based on the numerous available trials.


Assuntos
Dióxido de Carbono , Brasil , Corrosão , Raios gama , Reprodutibilidade dos Testes
2.
Appl Radiat Isot ; 152: 156-161, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302533

RESUMO

Meteorites have been arousing the curiosity of mankind since antiquity. However, the interest in these objects goes far beyond mere curiosity in the study of such materials, which has great importance due essentially to the information they can provide. The importance of studying meteorites is associated about the earliest conditions and processes during the formation and earliest history of the solar system. So, in this study, the characterization of two meteorite fragments was performed using X-ray computed microtomography (micro-CT) and X-ray microfluorescence (micro-XRF). These techniques were used for their non-destructive characteristics and the ability to provide information about the structure and composition the meteorites. The micro-CT images showed encrusted structures within both samples. However, while in Lunar meteorites spheroidal structures very similar to small grains internally grouped in clusters were found, in the Martian meteorite a very peculiar structure was identified. Besides that, the micro-CT it was also possible to evaluate the different density materials that compose the samples. The micro-XRF results accounted for the presence of the elements Si, Ca, Ti, Cr, Mn, Fe, Ni and Sr in the Lunar sample, as well as of Si, S, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Sr and Y in the Martian sample. The results obtained are effective for the characterization of meteorites, proving thus that it is possible to obtain important information about the chemical composition, as well as about the distribution and the internal structure of these materials, evaluating aspects such as density and porosity.

3.
Appl Radiat Isot ; 151: 274-279, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31228736

RESUMO

Metallic archeological artifacts have specific characteristics that differs them to the other classes of materials due to the transformations that occurs to them, mainly electrochemical. This way, a process called corrosion takes place, starting at the surface of the artifacts, changing the metals in oxides, sulphates, carbonates or other compounds that may result in substantial modifications in their morphology or the total mineralization. Possibly, most part of the archeological artifacts was already suffering this natural deterioration process, even before the period of time that they have remained buried. A number of techniques can be used for the analysis of these artifacts; however, most of them require physical sectioning, which is a complex time-consuming process. This work proposes the use of X-ray microtomography (microCT), which is a non-invasive and expeditious analysis technique, in order to identify the structures and texture of metallic archeological artifacts under incrustations. A set of artifacts found in excavations in the city of Rio de Janeiro (Brazil) were investigated. They show evident forms of degradation, and the incrustations did not allow to clearly identifying them. Through the microCT results is was possible to evaluate the structure of the artifacts, as well as to quantify the material loss caused by corrosion. Such results provided significant data about these historic pieces, which is important for a precise diagnostic about their conservation state, being a useful tool for preserving the morphology of the collected artifact.

4.
Plant Biol (Stuttg) ; 21(6): 1110-1118, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31173441

RESUMO

Seedling establishment is a critical step in environment colonisation by higher plants that frequently occurs under adverse conditions. Thus, we carried out an integrated analysis of seedling growth, water status, ion accumulation, reserve mobilisation, metabolite partitioning and hydrolase activity during seedling establishment of the native Caatinga species Piptadenia moniliformis (Benth.) Luckow & R.W. Jobson under salinity. Two-day-old seedlings were cultivated in vitro for 4 days in water agar (control) or supplemented with 50 or 100 mm NaCl. Biochemical determinations were performed according to standard spectrophotometric protocols. We found that 100 mm NaCl stimulated starch degradation, amylase activity and soluble sugar accumulation, but limited storage protein hydrolysis in the cotyledons of P. moniliformis seedlings. Although Na+ accumulation in the seedling affected K+ partitioning between different organs, it was not possible to associate the salt-induced changes in reserve mobilisation with Na+ toxicity, or water status, in the cotyledons. Remarkably, we found that starch content increased in the roots of P. moniliformis seedlings under 100 mm NaCl, probably in response to the toxic effects of Na+ . The mobilisation of carbon and nitrogen reserves is independently regulated in P. moniliformis seedlings under salt stress. The salt-induced delay in seedling establishment and the resulting changes in the source-sink relationship may lead to storage protein retention in the cotyledons. Possibly, the intensification of starch mobilisation in the cotyledons supported starch accumulation in the root as a potential mechanism to mitigate Na+ toxicity.


Assuntos
Carbono/metabolismo , Moniliformis/metabolismo , Nitrogênio/metabolismo , Plântula/metabolismo , Animais , Cotilédone/efeitos dos fármacos , Cotilédone/metabolismo , Moniliformis/efeitos dos fármacos , Salinidade , Plântula/efeitos dos fármacos , Sódio/metabolismo , Cloreto de Sódio/farmacologia
5.
Rev Sci Instrum ; 88(10): 105112, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29092468

RESUMO

A low-cost system able to perform microtomography of samples such as teeth, insects, or other small materials and low atomic numbers is presented. For this, a small flat panel type sensor was used. The process of characterization of the detector is detailed, as well as its main characteristics. The electromechanical control and the software used are also described. The advantages, some limitations, and comparisons with commercial systems are presented along with some three-dimensional volumetric reconstruction of different materials that served as samples during the development of the system.

6.
Plant Biol (Stuttg) ; 19(3): 335-344, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28039918

RESUMO

Reserve mobilisation, metabolite partitioning and reserve-degrading enzyme activity were studied in sunflower seedlings cultivated in vitro under a 12-h photoperiod or in the dark to investigate the involvement of source-sink relation and carbon starvation in the regulation of reserve mobilisation under continuous darkness. Reserves, metabolites and enzyme activity were determined with standard spectrophotometric methods. At the first 24 h of treatment (acclimation phase), darkness did not affect growth, but restricted carbon and nitrogen use, as indicated by sugar and amino acid accumulation in the different seedling parts. After 5 days of treatment (survival phase), extended darkness limited growth and retarded storage lipid mobilisation due to carbon starvation, as evidenced by the depletion of carbohydrates in cotyledons and hypocotyl, as well as the consumption of amino acids in hypocotyls and roots. Alterations in the source-sink relationship might have been a response to prolonged darkness, instead of a mechanism used to regulate reserve mobilisation, as these alterations cannot be associated with negative feedback mediated by metabolite accumulation. Storage lipid degradation depends, at least in part, on mechanisms that co-ordinately regulate the activities of lipases and isocitrate lyase. Taking these results together, it is possible that reserve mobilisation in sunflower seedlings cultivated in the dark might be regulated by mechanisms that perceive the absence of light and predict carbon starvation, adjusting reserve use according to future energy demands to allow, at least in the short term, seedling survival.


Assuntos
Enzimas/metabolismo , Helianthus/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Carbono/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Cotilédone/crescimento & desenvolvimento , Escuridão , Metabolismo dos Lipídeos , Fotoperíodo , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Plântula/fisiologia
7.
J Econ Entomol ; 109(2): 649-59, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26791817

RESUMO

This study was performed to investigate the activity of 19 dichloromethane-soluble fractions obtained from the methanolic extracts of 10 Annonaceae species against the fall armyworm, Spodoptera frugiperda (J. E. Smith). The stem bark of Duguetia lanceolata A. St.-Hil. showed the highest insecticidal activity, with a median lethal time (LT50) of 61.4 h and a median lethal concentration (LC50) of 946.5 µg/ml of diet. The dichloromethane-soluble fractions from six D. lanceolata specimens were subjected to evaluation of their activities against S. frugiperda and metabolomic analysis using hydrogen (1H) nuclear magnetic resonance (NMR) spectroscopy. Although all of the samples affected S. frugiperda mortality, their insecticidal activities varied according to the sample used in the experiments. Using partial least squares regression of the results, the D. lanceolata specimens were grouped according to their metabolite profile and insecticidal activity. A detailed analysis via uni- and bidimensional NMR spectroscopy showed that the peaks in the 1H NMR spectra associated with increased insecticidal activity could be attributed to 2,4,5-trimethoxystyrene, which suggests that this substance is involved in the insecticidal activity of the stem bark fraction of D. lanceolata.


Assuntos
Annonaceae/química , Controle de Insetos , Inseticidas/análise , Spodoptera , Animais , Annonaceae/metabolismo , Espectroscopia de Ressonância Magnética , Testes de Toxicidade
8.
Transplant Proc ; 46(6): 1781-3, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25131036

RESUMO

OBJECTIVES: Biliary atresia (BA) is the most common cause of liver transplantation in children. The earlier the treatment is done, the better the prognosis. The aim is to evaluate the impact of late diagnosis in children with BA, including the histopathological findings and success rate of biliary drainage in patients submitted to hepatic portoenterostomy (HPE). MATERIALS AND METHODS: A retrospective study of cases of BA in the Department of Pediatric Surgery, Federal University of São Paulo (UNIFESP) between 1998-2011. We found 63 cases of BA; of these, 42 underwent HPE and 21 were referred for liver transplantation. Clinic and pathologic data were evaluated. RESULTS: The HPE was performed with a mean age of 86.5 days, with 16.6% having the operation at 60 days or earlier; 59.2% between 61 and 90 days; and 23.8% after 90 days. Successful biliary drainage occurred in 31% of surgeries, Mean days when HPE drained was 69.1 days, and 94.3 days when the surgery did not drain (P = .05). All patients who were successfully drained, did not have grade IV fibrosis on histology. In cases in which surgery was performed after 60 days that had not drained, 25% had grade IV fibrosis on biopsy (P = .0469). CONCLUSION: The age of HPE relates to better prognosis of the disease. It was found that the rate of grade IV fibrosis is higher in no drainage patients. All patients with grade IV fibrosis had no biliary drainage.


Assuntos
Ductos Biliares Intra-Hepáticos/patologia , Atresia Biliar/patologia , Diagnóstico Tardio/efeitos adversos , Drenagem , Portoenterostomia Hepática , Atresia Biliar/complicações , Atresia Biliar/diagnóstico , Atresia Biliar/cirurgia , Biópsia , Progressão da Doença , Drenagem/métodos , Feminino , Fibrose , Seguimentos , Humanos , Lactente , Masculino , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
9.
Braz J Med Biol Res ; 46(4): 368-47, 2013 04.
Artigo em Inglês | MEDLINE | ID: mdl-23598646

RESUMO

Exaggerated blood pressure response (EBPR) during the exercise treadmill test (ETT) has been considered to be a risk factor for hypertension. The relationship of polymorphisms of the renin-angiotensin system gene with hypertension has not been established. Our objective was to evaluate whether EBPR during exercise is a clinical marker for hypertension. The study concerned a historical cohort of normotensive individuals. The exposed individuals were those who presented EBPR. At the end of the observation period (41.7 months = 3.5 years), the development of hypertension was analyzed within the two groups. Genetic polymorphisms and blood pressure behavior were assessed as independent variables, together with the classical risk factors for hypertension. The I/D gene polymorphism of the angiotensin-converting enzyme and M235T of angiotensinogen were ruled out as risk factors for hypertension. EBPR during ETT is not an independent influence on the chances of developing hypertension. No differences were observed between the hypertensive and normotensive individuals regarding gender (P = 0.655), skin color (P = 0.636), family history of hypertension (P = 0.225), diabetes mellitus (P = 0.285), or hypertriglyceridemia (P = 0.734). The risk of developing hypertension increased with increasing body mass index (BMI) and advancing age. The risk factors, which independently influenced the development of hypertension, were age and BMI. EBPR did not constitute an independent risk factor for hypertension and is probably a preclinical phase in the spectrum of normotension and hypertension.


Assuntos
Pressão Sanguínea/fisiologia , Hipertensão/fisiopatologia , Adolescente , Adulto , Fatores Etários , Idoso , Angiotensinogênio/genética , Pressão Sanguínea/genética , Índice de Massa Corporal , Estudos de Coortes , Teste de Esforço , Feminino , Humanos , Hipertensão/enzimologia , Hipertensão/genética , Masculino , Pessoa de Meia-Idade , Peptidil Dipeptidase A/genética , Polimorfismo Genético , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
10.
Braz. j. med. biol. res ; 46(4): 368-347, 05/abr. 2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-671389

RESUMO

Exaggerated blood pressure response (EBPR) during the exercise treadmill test (ETT) has been considered to be a risk factor for hypertension. The relationship of polymorphisms of the renin-angiotensin system gene with hypertension has not been established. Our objective was to evaluate whether EBPR during exercise is a clinical marker for hypertension. The study concerned a historical cohort of normotensive individuals. The exposed individuals were those who presented EBPR. At the end of the observation period (41.7 months = 3.5 years), the development of hypertension was analyzed within the two groups. Genetic polymorphisms and blood pressure behavior were assessed as independent variables, together with the classical risk factors for hypertension. The I/D gene polymorphism of the angiotensin-converting enzyme and M235T of angiotensinogen were ruled out as risk factors for hypertension. EBPR during ETT is not an independent influence on the chances of developing hypertension. No differences were observed between the hypertensive and normotensive individuals regarding gender (P = 0.655), skin color (P = 0.636), family history of hypertension (P = 0.225), diabetes mellitus (P = 0.285), or hypertriglyceridemia (P = 0.734). The risk of developing hypertension increased with increasing body mass index (BMI) and advancing age. The risk factors, which independently influenced the development of hypertension, were age and BMI. EBPR did not constitute an independent risk factor for hypertension and is probably a preclinical phase in the spectrum of normotension and hypertension.


Assuntos
Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Pressão Sanguínea/fisiologia , Hipertensão/fisiopatologia , Fatores Etários , Angiotensinogênio/genética , Índice de Massa Corporal , Pressão Sanguínea/genética , Estudos de Coortes , Teste de Esforço , Hipertensão/enzimologia , Hipertensão/genética , Polimorfismo Genético , Peptidil Dipeptidase A/genética , Estudos Retrospectivos , Fatores de Risco
11.
Rev. bras. plantas med ; 15(3): 325-331, 2013. tab
Artigo em Português | LILACS | ID: lil-684147

RESUMO

Métodos alternativos para o controle de doenças e pragas de plantas vêm sendo pesquisados buscando causar menores danos ao ambiente e a saúde humana. Diante disso, o objetivo deste estudo foi identificar extratos de plantas e óleos essenciais com possíveis efeitos sobre Phakopsora pachyrhizi, agente etiológico da ferrugem-asiática da soja. Assim, 61 extratos de plantas da flora nativa da região do Alto Rio Grande, Minas Gerais e cinco óleos essenciais obtidos comercialmente foram utilizados com a finalidade de testar os efeitos na germinação de urediniósporos do referido fungo. Foram utilizadas placas de Petri de 6 cm, com meio ágar-água, adicionado com 150 µL de extrato de planta ou 6 µL do óleo essencial misturado ao meio de cultura. Como testemunhas foram utilizadas 150 µL de Tween 20 a 0,7% e 150 µL de água destilada. Após, foram adicionados 50µL de uma suspensão de urediniósporos, na concentração de 2mg.5mL-1 e espalhados com alça de Drigalsky. As placas foram colocadas em BOD, a 23(±2ºC), por 4 horas. A germinação foi paralisada com adição de lactoglicerol. A avaliação da percentagem de esporos germinados foi realizada em microscópio de luz. Dentre os extratos vegetais testados, dez apresentaram percentual de germinação abaixo de 15%, tendo os extratos obtidos das plantas Pelargonium sp., Salvia officinalis, Lavandula officinalis, Mentha pulegium e M. arvensis apresentado germinação de esporos de 3,0%, 3,5%, 3,0%, 2,0% e 4,0%, respectivamente. Todos os óleos essenciais avaliados foram efetivos na inibição da germinação, com destaque para o óleo essencial de Caryophilus aromaticus, que apresentou percentagem de germinação de 5%, resultando num percentual de inibição de 50,0%.


Alternative methods to control plant diseases and plagues have been studied, in order to cause less damages to the environment and human health. The purpose of this study was to identify plant extracts and essential oils as possible alternative products that affect the urediniospore germination of Phakopsora pachyrhizi, the causal agent of the Asian soybean rust. Plant extracts (61) from the native flora of the Alto Rio Grande region, State of Minas Gerais, Brazil, as well as five commercial essential oils were used with the purpose of testing their effects on the germination of urediniospores of the referred fungus. 6cm Petri dishes were used, with water-agar medium, added with 150 µL of plant extract or 6 µL of essential oil mixed to the culture medium. As control, 150 µL of Tween 20 at 0.7% and 150 µL of distilled water were used. Then, 50 µL of a suspension of urediniospores were added, at a concentration of 2mg5mL-1 and spread with Drigalsky spatula. Then, the plates were put in BOD, at 23(±2ºC), for 4 hours. Germination was paralyzed by adding lactoglicerol. The percentage of spore germination was evaluated in a light microscope. Among the vegetal extracts tested, ten of them presented a germination percentage below 15%. The extracts from the Pelargonium sp., Salvia officinalis, Lavandula officinalis, Mentha pulegium and M. arvensis plants presented 3.0%, 3.5%, 3.0%, 2.0% and 4.0% of urediniospore germination, respectively. All the essential oils evaluated were effective in inhibiting germination, especially the Caryophilus aromaticus essential oil that presented 5.0% of germination, with 50.0% of inhibition.


Assuntos
Óleos Voláteis/análise , Extratos Vegetais/análise , Phakopsora pachyrhizi/isolamento & purificação , Germinação
12.
Rev. bras. plantas med ; 15(3): 352-362, 2013. tab
Artigo em Inglês | LILACS | ID: lil-684151

RESUMO

Aiming to contribute to the development of alternative control methods of the coffee leaf miner, Leucoptera coffeella (Guérin-Mèneville & Perrottet, 1842) (Lepidoptera: Lyonetiidae), a search for plants able to produce active substances against this insect was carried out, with species collected during different periods of time in the Alto Rio Grande region, (Lavras, Minas Gerais, Brazil). Coffee leaves containing L. coffeella mines were joined with 106 extracts from 77 plant species and, after 48 hours, the dead and alive caterpillars were counted. The extracts from Achillea millefolium, Citrus limon, Glechoma hederacea, Malva sylvestris, Mangifera indica, Mentha spicata, Mirabilis jalapa, Musa sapientum, Ocimum basiculum, Petiveria alliaceae, Porophyllum ruderale, Psidium guajava, Rosmarinus officinalis, Roupala montana, Sambucus nigra and Tropaeolum majus showed the highest mortality rates.


Visando contribuir para o desenvolvimento de métodos alternativos de controle do bicho-mineiro-do-cafeeiro, Leucoptera coffeella (Lepidoptera: Lyonetiidae), buscou-se selecionar plantas coletadas em diferentes épocas na região do Alto Rio Grande, (Lavras, Minas Gerais, Brasil) que contenham substâncias ativas contra este inseto. Folhas de cafeeiro com minas intactas de L. coffeella foram colocadas em contato com 106 extratos provenientes de 78 espécies vegetais e, após 48 horas, contaram-se as lagartas vivas e mortas. Os extratos de Achillea millefolium, Citrus limon, Glechoma hederacea, Malva sylvestris, Mangifera indica, Mentha spicata, Mirabilis jalapa, Musa sapientum, Ocimum basiculum, Petiveria alliaceae, Porophyllum ruderale, Psidium guajava, Rosmarinus officinalis, Roupala montana, Sambucus nigra e Tropaeolum majus, provocaram os maiores índices de mortalidade.


Assuntos
Produtos Biológicos/efeitos adversos , Lepidópteros/imunologia , Extratos Vegetais/análise
13.
J Mol Neurosci ; 48(1): 253-6, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22531885

RESUMO

There is a growing need to curate the overwhelming amount of sequencing data which is available in many public databases. For instance, new information shows that the M235T polymorphism at the angiotensinogen gene (AGT) is actually positioned at the position corresponding to the amino acid 268 and not 235. This polymorphism is filled as rs699 in the NCBI SNP database and results in the synthesis of a threonine (T) instead of a methionine (M). It has been widely studied and associated as an important risk factor for several vascular and neuropsychiatric conditions. We faced this new situation during the targeted sequencing of 360 chromosomes from Brazilian subjects studied for the M235T polymorphism, leading to the identification of a novel variation (rs141900991). This report explores the potential impact of such a dinucleotide variation, which promotes the change of alanine (A) to serine (S) at the AGT protein structure (A237S). Considering the previous M268T variation at the four possible haplotypes combined (MA, MS, TA and TS), we performed a comparative hydrophobicity simulation, using the Kyte-Doolittle algorithm, available at the CLB Bio workbench, in the four possible haplotypes. Additional simulations were performed using the programs PolyPhen, I-Mutant and SIFT, in order to evaluate the pathogenicity of both mutations. The predicted hydrophobicity decreases of a similar magnitude, with both MS and TA haplotypes, but the presence of both variations induces a major decrease in hydrophobicity, suggesting a cumulative effect, with possible modifying effect since that this variation per se would limit the hydrophobicity range and the latter chances in finding significant phenotype differences. A better characterization of this kind of variant is particularly important because the current genome wide scan analyses in complex disorders with cardiac or neural etiology are not generating reliable findings, especially if we consider the huge investment with such approach. Additional and unknown variations like this one, with potential modifying effect, might be more common than previously expected.


Assuntos
Angiotensinogênio/genética , Doenças Cardiovasculares/genética , Transtornos Mentais/genética , Polimorfismo de Nucleotídeo Único/genética , Brasil/epidemiologia , Doenças Cardiovasculares/epidemiologia , Bases de Dados Genéticas/normas , Variação Genética/genética , Haplótipos , Humanos , Transtornos Mentais/epidemiologia , Fatores de Risco
14.
Arq. bras. med. vet. zootec ; 64(2): 521-523, abr. 2012. tab
Artigo em Português | LILACS | ID: lil-622513

RESUMO

The influence of seasonality on chemical composition of cheese produced during different seasons, was verified as well as their microbiological quality. A total of 32 samples of colonial cheeses produced in the southwestern Paraná were analyzed. Although the study could be thoroughly not completed, the chemical results showed significant variations (p <0.05) among the cheeses produced during the spring and summer seasons. The microbiological results indicated that 50%, 100% and 12.5% of the samples were contaminated with fecal coliforms, Staphylococcus coagulase positive and Salmonella spp., so at odds with the microbiological standards established by the legislation.

15.
J Nematol ; 44(4): 321-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23482720

RESUMO

Microorganisms produce volatile organic compounds (VOCs) which mediate interactions with other organisms and may be the basis for the development of new methods to control plant-parasitic nematodes that damage coffee plants. In the present work, 35 fungal isolates were isolated from coffee plant rhizosphere, Meloidogyne exigua eggs and egg masses. Most of the fungal isolates belonged to the genus Fusarium and presented in vitro antagonism classified as mutual exclusion and parasitism against the nematode-predator fungus Arthrobotrys conoides (isolated from coffee roots). These results and the stronger activity of VOCs against this fungus by 12 endophytic bacteria may account for the failure of A. conoides to reduce plant-parasitic nematodes in coffee fields. VOCs from 13 fungal isolates caused more than 40% immobility to Meloidogyne incognita second stage juveniles (J2), and those of three isolates (two Fusarium oxysporum isolates and an F. solani isolate) also led to 88-96% J2 mortality. M. incognita J2 infectivity decreased as a function of increased exposure time to F. oxysporum isolate 21 VOCs. Gas chromatography-mass spectrometry (GC-MS) analysis lead to the detection of 38 VOCs produced by F. oxysporum is. 21 culture. Only five were present in amounts above 1% of the total: dioctyl disulfide (it may also be 2-propyldecan-1-ol or 1-(2-hydroxyethoxy) tridecane); caryophyllene; 4-methyl-2,6-di-tert-butylphenol; and acoradiene. One of them was not identified. Volatiles toxic to nematodes make a difference among interacting microorganisms in coffee rhizosphere defining an additional attribute of a biocontrol agent against plant-parasitic nematodes.

16.
Neotrop Entomol ; 40(1): 123-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21437494

RESUMO

We evaluated the effects of crude extracts from the plantain Plantago lanceolata and the bitter gourd Momordica charantia on the oviposition preference and development of the coffee leaf miner Leucoptera coffeella Guérin-Mèneville & Perrottet under laboratory and/or greenhouse conditions. The ovicidal effects of these extracts were also studied in a greenhouse. Plantago lanceolata and M. charantia extracts also underwent fractionation directed by oviposition tests with the coffee leaf miner. The extracts of both plants reduced L. coffeella oviposition and egg hatching, apparently as a result of action of plant metabolites on the embryo. Adults originating from eggs treated with the extracts exhibited similar survival rates, but a higher female/male ratio. Fecundity was reduced for females obtained from eggs treated with the M. charantia extract. Partial chemical analysis indicated that both extracts produced polar fractions that reduced the oviposition of L. coffeella on coffee leaves under laboratory conditions. The extracts of P. lanceolata and M. charantia have potential for use in the development of new products to control the coffee leaf miner.


Assuntos
Lepidópteros/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantago , Animais , Lepidópteros/anatomia & histologia , Lepidópteros/crescimento & desenvolvimento , Oviposição/efeitos dos fármacos , Controle Biológico de Vetores
17.
Appl Radiat Isot ; 67(10): 1824-8, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19540128

RESUMO

In order to guarantee the structural integrity of oil plants it is crucial to monitor the amount of weld thickness loss in offshore pipelines. However, in spite of its relevance, this parameter is very difficult to determine, due to both the large diameter of most pipes and the complexity of the multi-variable system involved. In this study, a computational modeling based on Monte Carlo MCNPX code is combined with computed radiography to estimate the weld thickness loss in large-diameter offshore pipelines. Results show that computational modeling is a powerful tool to estimate intensity variations in radiographic images generated by weld thickness variations, and it can be combined with computed radiography to assess weld thickness loss in offshore and subsea pipelines.

18.
Braz. j. microbiol ; 39(4): 756-760, Dec. 2008. tab
Artigo em Inglês | LILACS | ID: lil-504319

RESUMO

The aim of this work was to evaluate the antibacterial activity of Brazilian plants extracts against fish pathogenic bacteria. Forty six methanolic extracts were screened to identify their antibacterial properties against Streptococcus agalactiae, Flavobacterium columnare and Aeromonas hydrophila. Thirty one extracts showed antibacterial activity.


O objetivo deste trabalho foi avaliar a atividade antibacteriana de extratos de plantas brasileiras contra bactérias patogênicas para peixes. A atividade antibacteriana de quarenta e seis extratos metanólicos de plantas foi avaliada contra os agentes Streptococcus agalactiae, Flavobacterium columnare e Aeromonas hydrophila. Trinta e um extratos apresentaram atividade antibacteriana.


Assuntos
Aeromonas hydrophila , Antibacterianos , Bactérias , Peixes , Flavobacterium , Extratos Vegetais , Streptococcus agalactiae , Métodos , Métodos , Virulência
19.
Appl Radiat Isot ; 66(5): 587-92, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18339548

RESUMO

This work presents a methodology for digital radiography simulation for industrial applications using the MCNPX radiography tally. In order to perform the simulation, the energy-dependent response of a BaFBr imaging plate detector was modeled and introduced in the MCNPX radiography tally input. In addition, a post-processing program was used to convert the MCNPX radiography tally output into 16-bit digital images. Simulated and experimental images of a steel pipe containing corrosion alveoli and stress corrosion cracking were compared, and the results showed good agreement between both images.


Assuntos
Simulação por Computador , Intensificação de Imagem Radiográfica , Método de Monte Carlo
20.
Braz J Microbiol ; 39(4): 756-60, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24031303

RESUMO

The aim of this work was to evaluate the antibacterial activity of Brazilian plants extracts against fish pathogenic bacteria. Forty six methanolic extracts were screened to identify their antibacterial properties against Streptococcus agalactiae, Flavobacterium columnare and Aeromonas hydrophila. Thirty one extracts showed antibacterial activity.

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