Textbooks show that in cis-1,3-disubstituted cyclohexane molecule, the conformer with the substituents in the diaxial positions is higher in energy and hence, it presents a low population in the conformational equilibrium. The diaxial conformer is destabilized by the repulsion between the substituent groups and the axial hydrogen atoms on the same side of the ring. This interaction is known as the 1,3-diaxial interaction. In this study, the solvent effect on the conformational equilibria of cis-3-N-ethylaminocyclohexanol (cis-3-EACOL) and cis-3-N,N-diethylaminocyclohexanol (cis-3-DEACOL) has been assessed through the spin-spin coupling constant (3JHH). The results show that the diaxial conformation of cis-3-EACOL decreases from 92% in CCl4 (∆Gee−aa = 1.48 kcal mol−1) to 10% in DMSO-d6 (∆Gee−aa = −1.31 kcal mol−1). For cis-3-DEACOL the diaxial conformer decreased from 36% in CCl4 (∆Gee−aa = −0.33 kcal mol−1) to 7% in Pyridine-d5 (∆Gee−aa = −1.55 kcal mol−1). The stabilization of the diaxial conformer in nonpolar solvents takes place due to the O-H···N intramolecular hydrogen bond, which overcomes the 1,3-diaxial steric interactions.

Pharmaceutical cocrystals are composed of a drug and a coformer and are currently gaining attention due to their possibility of improving drug solubility. Quantitative determination of cocrystals is usually carried out by liquid chromatography method, but an alternative for the same is derivative UV spectrophotometry. Cocrystals of lamotrigine (LAM) were formed with nicotinamide (NIC) in order to improve the solubility of LAM. The aim of this study was to develop and validate a simple, low-cost, environment friendly, first-order derivative spectrophotometric method for simultaneous determination of LAM and NIC in cocrystals. Determination of LAM and NIC was performed at 244.4 and 271.6 nm, respectively. The method was accurate with recovery values of 98.21-101.52%, and precise (relative standard deviation (RSD) < 1.88%). Robustness evaluated by Plackett-Burman design showed no significant influence of the factors (pH, scanning speed, and sonication time) on LAM and NIC assays. The developed method was compared with a high performance liquid chromatography (HPLC) method and applied to study the cocrystal stoichiometry and solubility. The results indicated a molar ratio of 1:1 and that the cocrystal is more soluble than the drug. This study demonstrated that the first-order derivative method is feasible for drug and coformer determination in cocrystals and is a suitable alternative to chromatographic methods.

Biochar is a rich-carbon material highly functionalized, which allows the use as electrodes modifier for preconcentration and voltammetric determination of several species. This work describes a castor cake biochar production and chemical activation with different reaction conditions using HNO3 and/or H2O2. Biochar samples were characterized using scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, Fourier-transform infrared spectroscopy, Raman and zeta potential. Carbon paste modified electrodes (CPME) have been constructed using different biochar samples to evaluate the adsorptive capacity for the spontaneous preconcentration and voltammetric determination of Pb2+, Cd2+, Cu2+ and Ni2+ ions, paraquat and methyl parathion pesticides. The activation treatments promoted modifications in the elemental, morphological and structural biochar characteristics. Activated biochar CPMEs showed increase in the current signal around 15 and 2.5 times higher than unmodified and precursor biochar electrode, respectively. N2 sample (HNO3, 60 °C for 3.0 h) presented the better response signals for all compounds. This was attributed to the more effective surface oxidation, promoting a high porosity, acid character and amount of acid functional groups. Besides that, this greater analytical response allows the CPME-N2 application as a passive sampler for the voltammetric determination of inorganic and organic contaminants for environmental management in aqueous matrices.

Este trabalho apresenta o desenvolvimento e a avaliação de um sistema de tratamento de águas residuárias de suinocultura constituído de decantador e seguido de reator anaeróbio de manta de lodo (reator UASB), em escala real. O reator UASB foi construído de alvenaria e concreto armado. Coletaram-se amostras do esgoto bruto e do efluente do decantador e reator UASB, e se monitoraram os seguintes parâmetros: temperatura, pH, alcalinidade, ácidos voláteis totais (AVT), sólidos suspensos totais (SST), sólidos suspensos voláteis (SSV), demanda bioquímica de oxigênio (DBO) e demanda química de oxigênio (DQO), de acordo com os métodos estabelecidos pelo Standard Methods (APHA, 1998). Os resultados médios de remoção total de DQO e de DBO foram de 93 e 92%, respectivamente. As concentrações médias de DQO, DBO e SST no efluente final foram de 0,8, 1,8 e 0,8 g L-1, respectivamente. A carga orgânica volumétrica (COV) aplicada no reator UASB variou de 1,1 a 17,5 kg DQO m-3 d-1. O sistema decantador-reator UASB apresenta-se como alternativa promissora para o tratamento de águas residuárias de suinocultura.

This research presents the development and evaluation of a system for treatment of swine wastewaters constituted by slat settler, followed by upflow anaerobic sludge blanket (UASB) reactor, at full scale. The UASB reactor was completely made of masonry and reinforced concrete. The evaluation of the treatment system was carried out through samples collected in the influent and effluent from the settler and UASB reactor. The following parameters were analyzed: temperature, pH, alkalinity, total volatile acids (VFA), suspended solids (TSS), volatile suspended solids (VSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), according to the methods established by the Standard Methods (APHA, 1998). The mean results of COD and BOD removal were 93 and 92%, respectively. The mean concentrations of COD, BOD and TSS in the final effluent were 790, 1818 and 854 g L-1, respectively. The volumetric organic load (VOL) in the UASB reactor ranged from 1.1 to 17.5 kg COD m-3 d-1. The system slat settler-UASB reactor showed itself to be a promising alternative for the treatment of swine wastewaters.

O presente trabalho teve como objetivo comparar a eficiência de armadilhas de papel corrugado com a de armadilhas de colmo de bambu taquaril (Phyllostachys sp.) seco na captura de Dermanyssus gallinae, presentes em uma bateria de gaiolas de metal utilizadas na criação de galinhas de postura. A presença de ovos no interior de cada tipo de armadilha foi comparada por meio do teste de Qui-Quadrado e pelo intervalo de confiança para duas proporções. Os valores das somas de estágios móveis nas diferentes armadilhas a cada intervalo de tempo foram comparados utilizando-se o teste de Wilcoxon. A proporção de armadilhas contendo ovos não foi diferente nos dois tipos de armadilha (p < 0,05). O número total de estágios móveis capturados durante a coleta a cada dois dias de intervalo em cada tipo de armadilha foi diferente (p < 0,01), enquanto que as contagens, nas armadilhas de papelão, apresentaram distribuição normal e foram superiores aos valores de espécimes móveis capturados nas armadilhas de bambu.

This work aims to compare the performance of corrugated paper and "taquaril" bamboo (Phyllostachys sp.) straw traps for collecting (in sampling) Dermanyssus gallinae in a metal cages battery laying hens. The presence of eggs in the two trap models were compared using a Qui-square test and a proportion confidence interval test. Total daily values of mobile instars gathered in each type of trap were compared using the Wilcoxon's test. The amount of traps containing eggs was not different in neither of the traps (p < 0,05). The number of mobile instars sampled at every two days per trap model was different (p < 0,01). Counting in the corrugated paper traps showed a Gauss distribution histogram and was superior to the values of the bamboo straw traps.

O presente estudo teve como proposta controlar uma infestação natural de Rhipicephalus sanguineus em um canil pertencente à Escola de Veterinária da UFMG, com uma área de 72 m² e 25 cães de diversas raças. Um teste de sensibilidade a produtos acaricidas foi aplicado em uma amostra de carrapatos capturados no canil. Dos produtos testados: Amitraz 12,5% (Produto 1); uma associação de Alfametrina 2% e Dichlorvós 60% (produto 2); Deltametrina 5% (produto 3) e uma associação de Trichlorfon 77,6%, Coumaphós 1% e Cyfluthrin 1% (produto 4); somente os produtos 1 e 4 apresentaram 100% de eficácia. O Amitraz 12,5% foi utilizado no controle dos estádios de R. sanguineus presentes no ambiente do canil, com um esquema de 4 aplicações a cada 7 dias de intervalo. Para os estádios parasitários, um único tratamento com Flumetrina 1.0% pour-on foi empregado em todos os animais. A inspeção e o monitoramento do ambiente e dos animais foram realizados durante um período de um ano. Estas medidas de controle reduziram significativamente a população de carrapatos dentro do canil. O canil não apresentou infestação pelo carrapato nos seis meses seguintes aos tratamentos. Uma infestação leve foi observada no 7º mês pós-tratamento, quando foi realizada uma nova aplicação de Amitraz 12,5% no ambiente do canil e um novo tratamento com Flumetrina 1.0% pour-on nos animais, com resultados satisfatórios.

The present work was aimed at proposing a control measure for Rhipicephalus sanguineus in a naturally infected kennel of 72 m² of the UFMG Veterinary School with 25 dogs of different breeds. A sensitivity test to acaricide products was applied in a sample of R. sanguineus. Out of the acaricide products tested: 12.5% Amitraz (product 1); 2% Alfamethrin and 60% Dichlorvos association (product 2); 5% Deltamethrin (product 3) and the association between 77.6% Trichlorfon, 1.0% Coumaphos and 1.0% Cyfluthrin (product 4); only 1 and 4 products showed 100% efficacy. Amitraz (12.5%) was used for controlling R. sanguineus in the surrounding of the kennel, on which four treatments every seven days were carried out in the facilities. For parasitic R. sanguineus, a single topical treatment was used: Flumetrin 1.0% pour - on on all the 25 dogs. This control measure significantly reduced the population of R. sanguineus within the kennel. A slight infestation was observed in the seventh month after treatment. A new application of 12.5% Amitraz was done in the kennel as well as a new topical treatment with Flumetrin 1.0% pour - on on the dogs. The control procedure proposed in the present study was an emergency measure and its effectiveness was checked through environmental surveys throughout a one-year period.

Some reproductive parameters of adult stages of Amblyomma cajennense ticks were studied. The capacity of virgin females to reproduce by parthenogenesis was evaluated, during an experimental infestation, in absence of males, on a horse (Equus cabalus). Ticks were spread either completely free or in limited sites on the body of the animal. The engorged virgin females showed longer feeding periods and lighter body weights than those that had been fertilized. Some of these unmated females produced smaller egg masses, which had no embryonary development. On the other hand, females that had been inseminated produced larger egg masses, with normal embryonary development that led to viable larvae. Under the studied conditions, A. cajennense females did not reproduce by parthenogenesis.