A systematic study of transfection efficiency and cytotoxicity in HeLa cells using iron oxide nanoparticles prepared with organic and inorganic bases

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modeling of organic light-emitting diodes with graded concentration in the emissive multilayer

We model the electrical behavior of organic light-emitting diodes whose emissive multilayer is formed by blends of an electron transporting material, tris-(8-hydroxyquinoline) aluminum (Alq(3)) and a hole transporting material, N,N-'-diphenyl-N,N-'-bis(1,1(')-biphenyl)-4,4-diamine. The multilayer is composed of layers of different concentration. The Alq(3) concentration gradually decreases from the cathode to the anode. We demonstrate that these graded devices have higher efficiency and operate at lower applied voltages than devices whose emissive layer is made of nominally homogeneous blends. Our results show an important advantage of graded devices, namely, the low values of the recombination rate distribution near the cathode and the anode, so that electrode quenching is expected to be significantly suppressed in these devices. (C) 2004 American Institute of Physics.

Structure and Growth Kinetics of 3-Glycidoxypropyltrimethoxysilane-Derived Organic/Silica Hybrids at Different Temperatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of organic molecules originated during composting process

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Organic acid profile of commercial sour cassava starch

A presença de ácidos orgânicos no polvilho azedo, além de contribuir com aspectos como sabor e aroma, tem, conforme a literatura indica, correlação com a propriedade de expansão, que é um fator determinante no uso alimentício. Amostras de polvilho azedo foram coletadas nas Regiões Sul e Sudeste diretamente nas empresas ou no comércio. Foram preparadas para análise em cromatografia líquida de alta eficiência (CLAE), sendo que o cromatógrafo estava equipado com coluna Biorad Aminex HPX-87H para análise de ácidos orgânicos e detector refratométrico. As condições de análise envolveram o emprego da fase móvel ácido sulfúrico 0,005M, fluxo de 0,6 ml/min e temperatura da coluna de 60oC. Os ácidos quantificados foram lático (0,036 a 0,813 g/100g), acético (0 a 0,068 g/100g), propiônico (0 a 0,013 g/100g) e butírico (0 a 0,057 g/100g), presentes na fermentação natural. Os resultados revelaram grande variação entre as amostras, com diferenças mesmo dentro das Regiões. Algumas amostras apresentaram quantidades elevadas de ácidos, especialmente do ácido lático, mas nestas amostras os ácidos propiônico e butírico não foram detectados. A ausência do ácido butírico não era esperada, uma vez que esse ácido está diretamente relacionado com o aroma característico do polvilho azedo. O fato pode sugerir que a obtenção de algumas das amostras estudadas pode ter ocorrido sem o processo fermentativo natural.

The sensitization of the ligand-field state of the hexaammineruthenium(II) complex ion by organic compounds

The sensitized photolysis of [Ru(NH3)(6)](2+) by the organic dye rhodamine B and biacetyl was studied under conditions in which only the sensitizer absorbs. The reaction products resulting from ammonia aquation and Ru(II) to Ru(III) oxidation are the same for direct and sensitized photolysis. The energy transfer rate constant, calculated from the fluorescence quenching of rhodamine B, is similar to that estimated from the limiting quantum yield of the photosensitized photoaquation of the complex. Both reactions originate from a common reactive low-lying ligand-field (LF) state, which is also responsible for the direct photolysis reactions. This state, which leads directly to photoaquation, seems to have a certain charge transfer to solvent (CTTS) character, which is responsible for the photo-oxidation products. Sensitization is effective with rhodamine B (17 450 cm(-1)) and biacetyl (19 000 cm(-1)), whereas no reaction is observed with neutral red (16 900 cm(-1)). These results show that the excited state responsible for the photochemical reactions lies in the energy range between 16 900 cm(-1) and 17 700 cm(-1) and possesses spin-orbit character.

Influence of biosolids rate on chemical properties of an oxisol in São Paulo, Brazil

Organic residues may cause major health and environmental problems. This is the case in our study area, where more than 10 billion L per year of residential and industrial waste are produced. Land application of biosolids can be an economical solution by recycling waste and can provide valuable fertilizer if used correctly. The aim of this work was to study the effect of biosolids on the chemical properties of an Oxisol. The experiment was located at Ilha Solteira northwest of São Paulo State, Brazil. The soil was cropped to Sorghum bicolor.The field experimental design consisted of random blocks with six treatments and four replications of each treatment. Biosolids were surface applied to four treatments at rates of 5, 10, 20, and 40 Mg ha(-1) on a dry matter basis; in addition, a treatment with mineral fertilizer and a control were included. One year after biosolids application, soil samples were taken at 0-10, 10-20, and 20-40 cm. Organic matter content (Walkley-Black) and pH (CaCl2) were routinely determined. Cation exchange capacity, exchangeable bases (Ca, Mg, K), and P were determined by exchange resin extraction. No significant differences in any of the analyzed properties were found below the 20 cm depth. Extractable phosphorus (P) and potassium (K) increased with increasing biosolids rate in the top 20 cm, whereas calcium (Ca) and (Ma) magnesium content were not significantly influenced by biosolids. Soil pH decreased with increasing biosolids application. The sewage sludge application did not influence the sorghum production in the first year of culture, under unfavorable soil moisture conditions, but it influenced the dry matter.

Influence of the iron source on the solar photo-Fenton degradation of different classes of organic compounds

In this work the influence of two different iron sources, Fe(NO3)(3) and complexed ferrioxalate (FeOx), on the degradation efficiency of 4-chlorophenol (4CP), malachite green, formaldehyde, dichloroacetic acid (DCA) and the commercial products of the herbicides diuron and tebuthiuron was studied. The oxidation of 4CP, DCA, diuron and tebuthiuron shows a strong dependence on the iron source. While the 4CP degradation is favored by the use of Fe(NO3)(3), the degradation of DCA and the herbicides diuron and tebuthiuron is most efficient when ferrioxalate is used. on the other hand, the degradation of malachite green and formaldehyde is not very influenced by the iron source showing only a slight improvement when ferrioxalate is used. In the case of formaldehyde, DCA, diuron and tebuthiuron, despite of the additional carbon introduced by the use of ferrioxalate, higher mineralization percentages were observed, confirming the beneficial effect of ferrioxalate on the degradation of these compounds. The degradation of tebuthiuron was studied in detail using a shallow pond type solar flow reactor of 4.5 L capacity and 4.5 cm solution depth. Solar irradiation of tebuthiuron at a flow rate of 9 L h(-1), in the presence of 10.0 mmol L-1 H2O2 and 1.0 mmol L-1 ferrioxalate resulted in complete conversion of this herbicide and 70% total organic carbon removal. (c) 2005 Elsevier Ltd. All rights reserved.

Enhanced emission from Eu(III) beta-diketone complex combined with ether-type oxygen atoms of di-ureasil organic-inorganic hybrids

Organic-inorganic hybrids, named di-ureasils and described by polyether-based chains grafted to both ends to a siliceous backbone through urea cross linkages, were used as hosts for incorporation of the well-known coordination complex of trivalent europium (Eu3+) ions described by the formula [Eu(TTA)(3)(H2O)(2)] (where TTA stands for thenoyltrifluoroacetone). By comparing with Eu3+-doped di-ureasil without complex form the new materials prepared here enhanced the quantum efficiency for photoemission of Eu3+ ions. The enhancement can be explained by the coordination ability of the organic counterpart of the host structure which is strong enough to displace water molecules in [Eu(TTA)(3)(H2O)(2)] from the rare earth neighbourhood after the incorporation process. High intensity of Eu3+ emission was observed with a low non-radiative decay rate under ultraviolet excitation. The quantum efficiency calculated from the decay of D-5(0) emission was 74%, which in the same range of values previously obtained for the most efficient Eu3+ coordination compounds reported in literature. Luminescence, X-ray absorption and infrared absorption results considered together leads to a picture where the first coordination shell of Eu3+ is composed of the 6 oxygen atoms of the 3 beta-diketonate ligands and 2 ether-like oxygen atoms of the host. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Early loading of single crowns supported by 6-mm-long implants with a moderately rough surface: a prospective 2-year follow-up cohort study

AimTo evaluate prospectively the clinical and radiographic outcomes after 2 years of loading of 6 mm long moderately rough implants supporting single crowns in the posterior regions.Material and methodsForty SLActive Straumann (R) short (6 mm) implants were placed in 35 consecutively treated patients. Nineteen implants, 4.1 mm in diameter, and 21 implants, 4.8 mm in diameter, were installed. Implants were loaded after 6 weeks of healing. Implant survival rate, marginal bone loss and resonance frequency analysis (RFA) were evaluated at different intervals. The clinical crown/implant ratio was also calculated.ResultsTwo out of 40 implants were lost before loading. Hence, the survival rate before loading was 95%. No further technical or biological complications were encountered during the 2-year follow-up. The mean marginal bone loss before loading was 0.34 +/- 0.38 mm. After loading, the mean marginal bone loss was 0.23 +/- 0.33 and 0.21 +/- 0.39 mm at the 1- and 2-year follow-ups. The RFA values increased between insertion (70.2 +/- 9) and the 6-week evaluation (74.8 +/- 6.1). The clinical crown/implant ratio increased with time from 1.5 at the delivery of the prosthesis to 1.8 after 2 years of loading.ConclusionShort implants (6 mm) with a moderately rough surface loaded early (after 6 weeks) during healing yielded high implant survival rates and moderate loss of bone after 2 years of loading. Longer observation periods are needed to draw more definite conclusions on the reliability of short implants supporting single crowns.To cite this article:Rossi F, Ricci E, Marchetti C, Lang NP, Botticelli D. Early loading of single crowns supported by 6-mm-long implants with a moderately rough surface: a prospective 2-year follow-up cohort study.Clin. Oral Impl. Res. 21, 2010; 937-943.doi: 10.1111/j.1600-0501.2010.01942.x.

Kinetics of the reaction of alkylamines with 7,7,8,8-tetracyanoquinodimethane (TCNQ) in organic solvents

The following sequence of substitution reactions was studied spectrophotometrically in organic solvents: RNH2 + TCNQ →-HCN 7-substituted TCNQ →-HCN +RNH2 7.7-disubstituted TCNQ where R = butyl, octyl, dodecyl, and hexadecyl. The production of 7-(alkylamino)-7,7,8-tricyanoquinodimethanes proceeds via the formation of the anion radical of TCNQ (TCNQ-·) whose rate of appearance was found to be a function of the chain length of R, reaching a maximum for octylamine. The formation of TCNQ-· was sensitive to the solvent polarity and electron-donor power and was associated with a small enthalpy and a highly negative entropy of activation. Above a certain [C8H17NH2] the rate of disappearance of TCNQ-· was independent of the amine concentration, and the reaction had a much higher enthalpy and entropy of activation. The occurrence of tautomerism precluded an investigation of the conversion of 7-(octylamino)-7,8,8-tricyanoquinodimethane into 7,7-bis(octylamino)-8,8-dicyanoquinodimethane. A study of the reaction of octylamine with 7-morpholino-7,8,8-tricyanoquinodimethane (which does not exist in tautomeric forms) showed that the second substitution step proceeds with the same mechanism as the first one. The only difference between the two compounds (TCNQ and its monosubstituted morpholino derivative) is one of reactivity. © 1985 American Chemical Society.

Effects of vinasse upon the decomposition rate of Ocotea pulchella leaves in cerrado soil

Ocotea pulchella leaves placed on soil treated with vinasse lost 64.48% of their organic matter, whereas the leaves sampled in the control parcels lost 70.68%, after one year. -from Authors

Economic evaluation of nile tilapia juvenile production, feed with commercial ration and with primary production come from organic and inorganic fertilization

Study objective was to evaluate economically a Nile tilapia juvenile production, employing different feeding techniques. Tilapia fingerlings of 8g were stocked at 5 fish m-2 stocking in 50 and 150 m2 ponds, during 75 days. Treatments were: inorganic fertilization (P205 and N); organic fertilization (poultry manure) and commercial ration (32% CP). Water quality results were considered adequate for fish rearing. In juvenile production there were significant differences among treatments for individual final weight, medians were: for inorganic fertilization 12.92g (13.35g in 50 m2 and 12.49g in 150 m2); for organic fertilization 30.55g (33.69g in 50 m2 and 27.40g in 150 m2) and for commercial ration 51.23g (52.90g in 50 m2 and 50.15g in 150 m2). Survival rate ranged from 63 to 71%, with no statistic difference. Commercial ration was effective to bigger juvenile production, with a better market value. Costs considered in economic analyses were tilapia fingerlings, fertilizer, ration, labor and installation depreciation. Obtained information showed that juvenile production in 50 m2 ponds is not viable economically and, in 150 m2, production is viable only when commercial ration is used.

Design of a state observer using decay rate LMI constraints for fault detection in mechanical systems

Nowadays, one of the most important concerns for many companies is to maintain the operation of their systems without sudden equipment break down. Because of this, new techniques for fault detection and location in mechanical systems subject to dynamic loads have been developed. This paper studies of the influence of the decay rate in the design of state observers using LMI for fault detection in mechanical systems. This influence is analyzed by the performance index proposed by Huh and Stein for the condition of a state observer. An example is presented to illustrate the methodology discussed.

Dairy goat health management and milk production on organic and conventional system in Brazil

The aimed of this article is to measure risk factors on health and milk production on organic and conventional dairy goats in Brazil. Two experimental groups (organic and conventional) were evaluated simultaneously. The study design was completely randomized. The organic herd consisted of 25 goats and 15 kids. In the conventional production system, a dairy herd comprising 40 goats and 20 kids participated in the study. Data on milk production and health management were available from January 2007 to December 2009. The abortion rate in the conventional system was 5% (2/40) whereas in organic system no abortion was diagnosed (0/25). The mortality rate at weaning in the conventional system was 5% (2/40) and in the organic system was 8% (2/25). Milk production was lower (2.20 kg/day) in organic than conventional system (2.66 kg/day). Goats and kids in organic farm had a higher FEC (386±104 and 900±204, respectively) (p<0.05) than those in conventional farm (245±132 and 634±212, respectively). In addition, Saanen kids had higher FEC (p<0.001) than goats. Treatment with antiparasitic drugs was higher in conventional system (50%) than organic system (1.3%).