885 resultados para Microwave-assisted Solvothermal
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Powdery mildew is one of the most serious diseases of soybean and is found in all producing countries. The purpose of this study was to validate microsatellite markers previously identified as associated with resistance to powdery mildew in soybean. The study was conducted in two F, parent populations with contrasting resistance to powdery mildew, In the analysis 10 SSR primers were used for the populations. and tour polymorphic markers were identified for cross I (MGBR95-20937 x IAC-Foscarin 31) and three for cross 2 (MGBR-46 x Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) 48). The Chi-square analysis of the phenotypic evaluation confirmed the expected segregation (3: 1) of a dominant gene related to resistance. The polymorphic markers also segregated as expected (1:2:1). The markers Sat 366 and Sat 393 in the crosses 1 and 2. respectively, located at 9.41 and 12.45 cM from the gene. were considered promising for marker-assisted selection for resistance to powdery mildew in soybean. at a selection efficiency of 92.7% and 60.3% respectively.
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A possibilidade do desenvolvimento de técnicas de aplicação de produtos fitossanitários mais seguras, com menores volumes de calda, número de aplicações e deriva, aliados à necessidade de se obter melhores níveis de controle dos agentes nocivos às plantas cultivadas, justificam o uso da assistência de ar junto à barra de pulverização. Com o objetivo de avaliar a deposição da pulverização na cultura do feijoeiro (Phaseolus vulgaris), em presença e ausência da assistência de ar junto à barra de pulverização, com diferentes pontas de pulverização e volumes de calda, foi conduzido um experimento em delineamento inteiramente casualizado, utilizando-se como traçador o óxido cuproso. Alvos artificiais (papel filtro com 3 x 3 cm) foram afixados nas superfícies adaxial e abaxial de folíolos posicionados nos terços superior e inferior de plantas, selecionadas ao acaso, distribuídas perpendicularmente ao deslocamento do pulverizador. Após a aplicação do traçador os coletores foram lavados individualmente em solução extratora de ácido nítrico a 1,0 mol L-1. A determinação quantitativa dos depósitos foi realizada com o uso da espectrofotometria de absorção atômica. A assistência de ar junto à barra de pulverização não aumentou a deposição do traçador em folíolos de feijoeiro, aos 48 dias após a emergência da cultura.
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This letter reports microwave dielectric measurements performed in the antiferroelectric phase of NaNbO3 ceramics from 100 to 450 K. Remarkable dielectric relaxation was found within the antiferroelectric phase and in the vicinity of the ferroelectric-antiferroelectric phase transition. Such dielectric relaxation process was associated with relaxations of polar nanoregions with strong relaxor-like characteristic. In addition, the microwave dielectric measurements also revealed an unexpected and unusual anomaly in the relaxation strength, which was related to a disruption of the antiferroelectric order induced by a possible AFE-AFE phase transition. (C) 2004 Elsevier Ltd. All rights reserved.
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Density functional theory (DFT) calculations point out that the participation of water can effectively lower the barrier height for the isomerization process between hydrated oxide cation, MO(H2O)(+), and dihydroxide cation, M(OH)(2)(+), (M = V, Nb and Ta). The catalytic effect is achieved by a water-assisted mechanism in which water acts as proton donor and acceptor, via a transition structure corresponding to a six-membered ring. In the case of vanadium atom, the presence of two water molecules has been taken into account and the tautomerization becomes nearly barrierless, decreasing both the stability of the transition structures relative to intermediates and the depths of wells associated with the intermediates. (C) 2003 Elsevier B.V. All rights reserved.
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The non-ohmic and dielectric properties as well as the dependence on the microstructural features of CaCu(3)Ti(4)O(12)/CaTiO(3) ceramic composites obtained by conventional and microwave sintering were investigated. It was demonstrated that the non-ohmic and dielectric properties depend strongly on the sintering conditions. It was found that the non-linear coefficient reaches values of 65 for microwave-sintered samples and 42 for samples sintered in a conventional furnace when a current density interval of 1-10 mA cm(-2) is considered. The non-linear coefficient value of 65 is equivalent to 1500 for samples sintered in the microwave if a current interval of 5-30 mA is considered as is shortly discussed by Chung et al (2004 Nature Mater. 3 774). Due to a high non-linear coefficient and a low leakage current (90 mu A) under both processing conditions, these samples are promising for varistor applications. The conventionally sintered samples exhibit a higher relative dielectric constant at 1 kHz (2960) compared with the samples sintered in the microwave furnace (2100). At high frequencies, the dielectric constant is also larger in the samples sintered in the conventional furnace. Depending on the application, one or another synthesis methodology is recommended, that is, for varistor applications sintered in a microwave furnace and for dielectric application sintered in a conventional furnace.
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SrBi4Ti4O15 (SBTi) thin films were obtained by the polymeric precursor method and crystallized in a domestic microwave oven. For comparison, films were also crystallized in a conventional furnace at 700 degrees C for 2 h. Structural and morphological characterization of the SBTi thin films was investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. Using platinum coated silicon substrates configuration, ferroelectric properties of the films were determined with remanent\polarization P-r and a coercive field E-c of 5.1 mu C/cm(2) and 135 kV/cm for the film thermally treated in the microwave oven and 5.4 mu C/cm(2) and 85 kV/cm for the film thermally treated in conventional furnace, respectively. The films thermally treated in the conventional furnace exhibited excellent fatigue-free characteristics up to 10(10) switching cycles indicating that SBTi thin films can be a promise material for use in non-volatile memories. (C) 2007 Elsevier B.V. All rights reserved.
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Thin films of SrBi4Ti4O15 (SBTi), a prototype of the Bi-layered-ferroelectric oxide family, were obtained by a soft chemical method and crystallized in a domestic microwave oven. For comparison, films were also crystallized in a conventional method at 700 degrees C for 2 h. Structural and morphological characterization of the SBTi thin films were investigated by Xray diffraction (XRD) and atomic force microscopy (AFM), respectively. Using platinum coated silicon substrates, the ferroelectric properties of the films were determined. Remanent polarization P-r and a coercive field E-c values of 5.1 mu C/cm(2) and 135 kV/cm for the film thermally treated in the microwave oven and 5.4 mu C/cm(2) and 85 kv/cm for the film thermally treated in conventional furnace were found. The films thermally treated in the conventional furnace exhibited excellent fatigue-free characteristics up to 10(10) switching cycles indicating that SBTi thin films are a promising material for use in non-volatile memories. (C) 2007 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Perovskites oxides win importance by its properties and commercials applications, they have a high thermal stability, have conductive properties, electrical, catalytic, electro catalytic, optical and magnetic, and are thermally stable. Because of these properties, are being widely studied as carriers of oxygen in the process of power generation with CO2 capture. In this work, the base carrier system La1-xMexNiO3 (Me = Ca and Sr) were synthesized by the method via the combustion reaction assisted by microwave. were synthesized from the combustion reaction method by microwave process. This method control the synthesi`s conditions to obtain materials with specific characteristics. The carriers calcined at 800 ° C/2h were analyzed by thermal analysis (TG-DTA), to verify its thermal stability, X-ray diffraction (XRD) to verify the phase formation, with subsequent refinement by the Rietveld method, to quantify the percentage of phases formed, the surface area by BET method was determined, scanning electron microscopy (SEM) was obtained to evaluate the material morphology and temperature programmed reduction (TPR) was done to observe the metallic phase of the nickel. After all proposed characterization and analysis of their results can be inferred to these oxides, key features so that they can be applied as carriers for combustion reactions in chemical cycles. The final products showed perovskite-type structures K2NiF4 (main) and ABO3.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to evaluate whether seasonality affects human-assisted reproduction treatment outcomes. For this, 1932 patients undergoing intracytoplasmic sperm injection (ICSI) were assigned to a season group according to the day of oocyte retrieval: winter (n = 435), spring (n = 444), summer (n = 469) or autumn (n = 584). Analysis of variance was used to compare the ICSI outcomes. The fertilization rate was increased during the spring (winter: 67.9%, spring: 73.5%, summer: 68.7% and autumn: 69.0%; p < 0.01). In fact, a nearly 50% increase in the fertilization rate during the spring was observed (odds ratio 1.45, confidence interval 1.20-1.75; p < 0.01). The oestradiol concentration per number of oocytes was significantly higher during the spring (winter: 235.8 pg/mL, spring: 282.1 pg/mL, summer: 226.1 pg/mL and autumn: 228.7 pg/mL; p = 0.030). This study demonstrates a seasonal variability in fertilization after ICSI, where fertilization is higher during the spring than at any other time.
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Background: The selection of developmentally competent human gametes may increase the efficiency of assisted reproduction. Spermatozoa and oocytes are usually assessed according to morphological criteria. Oocyte morphology can be affected by the age, genetic characteristics, and factors related to controlled ovarian stimulation. However, there is a lack of evidence in the literature concerning the effect of gonadotropin-releasing hormone (GnRH) analogues, either agonists or antagonists, on oocyte morphology. The aim of this randomized study was to investigate whether the prevalence of oocyte dysmorphism is influenced by the type of pituitary suppression used in ovarian stimulation.Methods: A total of 64 patients in the first intracytoplasmic sperm injection (ICSI) cycle were prospectively randomized to receive treatment with either a GnRH agonist with a long-term protocol (n: 32) or a GnRH antagonist with a multi-dose protocol (n: 32). Before being subjected to ICSI, the oocytes at metaphase II from both groups were morphologically analyzed under an inverted light microscope at 400x magnification. The oocytes were classified as follows: normal or with cytoplasmic dysmorphism, extracytoplasmic dysmorphism, or both. The number of dysmorphic oocytes per total number of oocytes was analyzed.Results: Out of a total of 681 oocytes, 189 (27.8 %) were morphologically normal, 220 (32.3 %) showed cytoplasmic dysmorphism, 124 (18.2%) showed extracytoplasmic alterations, and 148 (21.7%) exhibited both types of dysmorphism. No significant difference in oocyte dysmorphism was observed between the agonist- and antagonist- treated groups (P > 0.05). Analysis for each dysmorphism revealed that the most common conditions were alterations in polar body shape (31.3%) and the presence of diffuse cytoplasmic granulations (22.8%), refractile bodies (18.5%) and central cytoplasmic granulations (13.6%). There was no significant difference among individual oocyte dysmorphisms in the agonist- and antagonist-treated groups (P > 0.05).Conclusions: Our randomized data indicate that in terms of the quality of oocyte morphology, there is no difference between the antagonist multi-dose protocol and the long-term agonist protocol. If a GnRH analogue used for pituitary suppression in IVF cycles influences the prevalence of oocyte dysmorphisms, there does not appear to be a difference between the use of an agonist as opposed to an antagonist.
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Background: It is not well established whether the increased number of leukocytes in the seminal fluid impairs the outcomes of assisted reproductive technology (ART). This investigation analysed the outcomes of the intracytoplasmic sperm injection (ICSI) and intracytoplasmic morphologically selected sperm injection (IMSI) cycles in couples in which the male partner exhibited leukocytospermia.Methods: A total of 100 cycles in 100 couples were included in this study. For the ICSI or IMSI procedures, the patients were divided into two groups according to the presence or absence of leukocytospermia and then matched by (female) age:- ICSI: Group I (n = 25): Leukocytospermia - semen samples with a leukocyte count of greater than or equal to 1 x 10(6)/mL; and Group II (n = 25): Non-leukocytospermia - semen samples with a leukocyte count < 1 x 10(6)/mL.- IMSI: Group I (n = 25): Leukocytospermia; and Group II (n = 25): Non-leukocytospermia.The endpoints included the rates of fertilisation, implantation, clinical pregnancy, miscarriage, ongoing pregnancy and live birth. Student's t-tests, Mann-Whitney tests and Chi-square tests were performed, and P < 0.05 was considered significant.Results: The data from the ICSI groups showed that leukocytospermia did not have a negative influence on the rates of fertilisation (Group I: 57.9+/-30.2%, Group II: 61.9+/-27.7%; P = 0.74), implantation (Group I: 12.3%; Group II: 13.5%; P = 0.93), clinical pregnancy (Group I: 24%; Group II: 24%; P = 1.0), miscarriage ( Group I: 0, Group II: 0), ongoing pregnancy (Group I: 24%; Group II: 24%; P = 1.0), or live births (Group I: 24%; Group II: 24%; P = 1.0). Similarly, the data from the IMSI groups also showed that the leukocytospermia did not have a negative influence on the rates of fertilisation (Group I: 67.6+/-24.6%, Group II: 59.5+/-28.1%; P = 0.36), implantation (Group I: 17.5%; Group II: 16.7%; P = 0.90), clinical pregnancy (Group I: 28%; Group II: 24%; P = 1.0), miscarriage (Group I: 14.3%; Group II: 0; P = 0.33), ongoing pregnancy (Group I: 24%; Group II: 24%; P = 1.0), or live births (Group I: 24%, 6/25; Group II: 24%, 6/25; P = 1.0).Conclusions: The results indicate that the leukocytospermia may not have a negative effect on the outcomes of ICSI or IMSI cycles. Nevertheless, it seems that it is necessary to more precisely determine the effects, if any, of seminal leukocytes on fertilisation and implantation processes. Such efforts will help to establish a more reliable leukocyte threshold, which could eventually demonstrate whether there is a negative influence on the ART procedures.
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Vaginal weight cone (VWC) versus assisted pelvic floor muscle training (APFMT) in the treatment of urinary incontinence (UI) in women.One hundred three incontinent women were randomly distributed into two groups: group G1 (n = 51) treated with VWC and G2 (n = 52), APFMT. The following parameters were performed initially and after treatment: (1) clinical questionnaire, (2) visual analogue scale (VAS), (3) 60-min pad test, and (4) subjective and objective assessment of pelvic floor muscle (PFM).There was a significant decrease in nocturia and urine loss after treatment in both groups (p < 0.05). In VAS, there was a significant improvement of all parameters in both groups (p < 0.05). The pad test showed significant decrease in both groups (p < 0.05). There was a significant increase of PFM strength in both groups (p < 0.05).There was no difference between groups treated with VWC and APFMT.