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Abstract  

Captopril (CAP) was the first commercially available angiotensine-converting enzyme (ACE) inhibitor. In the anti-hypertensive therapy is considered the selected drug has to be therapeutically effective together with reduced toxicity. CAP is an antihypertensive drug currently being administered in tablet form. In order to investigate the possible interactions between CAP and excipients in tablets formulations, differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis completed by X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR) were used for compatibility studies. A possible drug-excipient interaction was observed with magnesium stearate by DSC technique.

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Summary  

Seventy nine samples, including soil and rock, were collected from the agrestic region of the State of Pernambuco, Brazil. The activity concentrations of 238U and 226Ra in the samples were determined by gamma-spectrometry using an HPGe detector. The concentrations of 238U were 22 Bq . kg-1 to 22 kBq . kg-1. The concentrations of 226Ra were 14 Bq . kg-1   to 17 kBq . kg-1. The 238U/226Ra ratios in the soil were 0.7 to 3.4 (arithmetic mean 1.7). The radiometric data were evaluated to explain 238U and 226Ra migration in the soil and the possible consequences to the environment.

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Bianca V. Sousa, Karoline D. Brito, José J. N. Alves, Meiry G. F. Rodrigues, Carlos M. N. Yoshioka, and Dilson Cardoso

Abstract

Current specifications for gasoline impose strong restrictions on the content of aromatic compounds. Isomerization of normal paraffins to isoparaffins is considered an important petroleum reaction for the production of clean gasoline to improve its Research Octane Number (RON) and Motor Octane Number (MON). The isoparaffins are considered as an alternative to the use of oxygenated and aromatic compounds, whose maximum contents are subjected to strict regulations in order to protect the environment. In this work, catalysts supported on mordenite were obtained by competitive ion exchange using aqueous solutions of platinum complexes. Different concentrations of platinum were tested for the isomerization of n-hexane. All the catalysts obtained were shown to be selective to the formation of isomers with high-octane number, which are the products of greatest interest in the oil refining industry. The highest conversion and the best selectivity for 2,3-dmC4 di-branched component, the isomer with the highest octane number, were found with the 1.10 wt% Pt/HMOR.

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Acta Agronomica Hungarica
Authors: P. Almeida, L. Dinis, J. Coutinho, T. Pinto, R. Anjos, J. Ferreira-Cardoso, M. Pimentel-Pereira, F. Peixoto, and J. Gomes-Laranjo

Studies on gas exchange parameters were made at different temperatures and radiation levels in seven seedling populations of chestnut cultivar Judia from different parts of the Trás-os-Montes region, Portugal. Differences were found for the optimal temperature, which was 31°C for JD7, 31.5°C for JD5, 32°C for JD2, 32.5°C for JD4, 33°C for JD3 and JD6, and 33.5°C for JD1 and the ink-resistant hybrid BRO310. At these values, rates of photosynthesis ranged between 8.7 and 13.4 mmol CO 2 m −2 s −1 for JD6 and JD7, while the light conditions allowing 90% of maximal photosynthesis varied between 650 (JD6) and 1385 (JD4) μmol m −2 s −1 . JD1 showed the highest value of leaf water potential, −0.35 Mpa, and JD6, JD7 and BRO310 the lowest, −0.65 Mpa. JD1 also showed the second lowest stomatal conductance (93 mmol m −2 s −1 ) and transpiration rate (3.0 mmol H 2 O m −2 s −1 ).In relation to the photosynthetic pigments, JD3 and JD7 were the most sun-loving clones having the highest values for the Chl a / b ratio (3.2 and 3.3, respectively), while JD1 had the lowest Chl/Car ratio (3.9). The overall results suggested that the JD3, JD1 and JD5 populations might increase heat stress tolerance in Judia.

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Journal of Thermal Analysis and Calorimetry
Authors: J. R. J. Delben, S. S. Rojas, K. Miazato, P. Melnikov, A. A. S. T. Delben, C. X. Cardoso, and A. Job
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Journal of Thermal Analysis and Calorimetry
Authors: V. A. Cardoso, L. M. Nunes, J. C. O. Santos, I. M. G. Santos, M. M. Conceiçăo, J. R. Santos Jr., and A. G. Souza
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Journal of Radioanalytical and Nuclear Chemistry
Authors: N. Canha, M. Freitas, M. Almeida-Silva, S. Almeida, H. Dung, I. Dionísio, J. Cardoso, C. Pio, A. Caseiro, T. Verburg, and H. Wolterbeek

Abstract  

One Plus Sequential Air Sampler—Partisol was placed in a small village (Foros de Arrão) in central Portugal to collect PM10 (particles with an aerodynamic diameter below 10 μm), during the winter period for 3 months (December 2009–March 2010). Particles masses were gravimetrically determined and the filters were analyzed by instrumental neutron activation analysis to assess their chemical composition. The water-soluble ion compositions of the collected particles were determined by Ion-exchange Chromatography. Principal component analysis was applied to the data set of chemical elements and soluble ions to assess the main sources of the air pollutants. The use of both analytical techniques provided information about elemental solubility, such as for potassium, which was important to differentiate sources.

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Journal of Thermal Analysis and Calorimetry
Authors: M. R. Serafini, P. P. Menezes, L. P. Costa, C. M. Lima, L. J. Quintans Jr, J. C. Cardoso, J. R. Matos, J. L. Soares-Sobrinho, S. Grangeiro Jr, P. S. Nunes, L. R. Bonjardim, and A. A. S. Araújo
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Journal of Thermal Analysis and Calorimetry
Authors: M. R. Serafini, P. P. Menezes, L. P. Costa, C. M. Lima, L. J. Quintans Jr, J. C. Cardoso, J. R. Matos, J. L. Soares-Sobrinho, S. Grangeiro Jr, P. S. Nunes, L. R. Bonjadim, and A. A. S. Araújo

Abstract

In this investigation, the study of inclusion complexes formation between p-cymene and β-cyclodextrin using the methods of physical mixture, paste (PC) and slurry (SC), was evaluated. The results of DSC and TG/DTG showed that the products prepared by PC and SC methods were able to incorporate greater amounts of p-cymene, as evidenced by the weight loss of 7.15 and 3.97%, respectively, which occurred between 120 and 270 °C. SEM images showed decreased size of the household, especially in the SC product. The absorption bands in the IR spectrum, characteristic of p-cymene, were also identified in the preparations, indicating the presence of the compound in the complex.

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