The amorphous, mesoporous SiO2-SO3H catalyst with a surface area of 115 m2 g-1 and 1.32 mmol H+ per g was very efficient for the protonation of ketones on a 10% (m/m) basis, and the catalyst-bound intermediates can be trapped by polyalcohols to produce ketals in high yields or suffer aldol condensations within minutes under low-power microwave irradiation. The same catalyst can easily reverse the ketalization reaction.

Abstract: Evidence of pollution by heavy metals have been detected in the city of Guayaquil, province of Guayas, coastal Ecuador. The water and sediment in the mangrove environs of Puente Portete in Estero Salado were tested for concentrations of cadmium (Cd) and lead (Pb), as well as the following organisms: gastropods, including Littorina varia and Cerithidea mazatlanica, and the leaves of Rhizophora racemosa, Laguncularia racemosa, Avicennia germinans, and Conocarpus erectus. The samples were analyzed using flame atomic absorption spectrophotometry. The values of Cd and Pb in water and sediment exceeded the permissible limits established by Ecuadorian and Canadian standards. The gastropod species L. varia and C. mazatlanica were the best indicator organisms for detecting pollution by accumulating 2.45 ± 0.49 ppm Pb and 1.49 ± 0.67 ppm Cd, respectively. Because of the low bioavailability of heavy metals in sediments, mangrove plants did not accumulate Cd and Pb in leaves.

Resumen: Existen evidencias de contaminación por metales pesados en el Estero Salado, localizado en la ciudad de Guayaquil, provincia del Guayas, en la costa de Ecuador. Con la finalidad de identificar organismos bioindicadores de contaminación por metales pesados, se estudió la concentración de Cd y Pb en agua, sedimento, hojas de mangles como Rhizophora racemosa, Avicennia germinans, Conocarpus erectus y Laguncularia racemosa, y gasterópodos como Littorina varia y Cerithidea mazatlanica, que se encontraban a nivel del Puente Portete en el Estero Salado. Las muestras fueron analizadas por espectrofotometría de absorción atómica de flama. Los valores de Cd y Pb en agua y sedimento superaron a los límites permisibles establecidos en las normas ecuatoriana y canadiense. Los gasterópodos L. varia y C. mazatlanica demostraron ser los mejores bioindicadores de contaminación al acumular en sus tejidos blandos 2,45(0,49 mg kg-1 de Pb y 1,49(0,67 mg kg-1 de Cd, respectivamente. Los mangles no acumularon en sus hojas Cd y Pb por la baja biodisponibilidad en el sedimento.

Agronomic efficiency (AE) of soil fertilization of macro nutrients associated with vigor and production of new hybrids released for Valles Altos in the State of Mexico was calculated. With the concept "omission plots" of macro nutrients, modality of Liebigs law of the minimum, a full factorial test for Puma hybrids 1076, H-59, H-47, H-50 and Z-60 for eight fertilization doses was set. The formula "high yield" in kg ha-1 was 240N-90 P2O5- 80 K2O- 60S-50MgO-380CaO and labeled as (T8); and the subsequent omission of a macro-nutrient treatments were designed: T1(-N), T2(-P), T3(-K), T4(-S), T5(-Mg), T6(-Ca) amd T7 (from the "farmer" equivalent to 70% of NPK dose of "complete dose", but without S, Mg and Ca). It was seeded with 90 000 seeds per hectare in soil with "irrigation of establishment" on May 13th in the town of Temascalcingo, State of Mexico at 2372 masl. By quadruplicated three groups of variables were measured 1) flowering plant; 2) mature cob; and 3) harvest. AE calculation was made with kg of corn grain produced per kg of NPK added to the soil; and was due to differences in corn grain yield from farmer control each omission plot of -N, -P and -K. The variables were analyzed with SAS and separated the means by Tukey 5%. Grain production was correlated with leaf greenness index, nitrate and potassium content in cell extract. The results indicated: AE of nitrogen was 20.9 kg of corn grain per kg of N applied to the soil, phosphorus 10.4 kg of grain per kg of P2O5 and potassium 8.41 kg of grain per kg of K2O. Low production of corn grain was correlated to less than 35 SPAD units and less than 300 mg L-1 of N-NO3 were correlated.

Se calculó la eficiencia agronómica (EA) de la fertilización al suelo de macro nutrimentos asociado a vigor y producción de nuevos híbridos liberados para Valles Altos en el Estado de México. Con el concepto de "parcelas de omisión" de macro nutrimentos, modalidad de la Ley del Mínimo de Leibniz, se instaló prueba de un factorial completo de los híbridos Puma 1076, H-59, H-47, H-50 y Z-60 por ocho dosis de fertilización. La fórmula "de alto rendimiento" en kg ha-1 fue 240N-90P2O5-80K2O- 60S-50MgO-380CaO y se etiquetó como (T8); y con la sucesiva omisión de un macro-nutrimento se diseñaron los tratamientos de: T1(-N), T2(-P), T3(-K), T4(-S), T5(-Mg), T6(-Ca) y T7 (del "agricultor" equivalente al 70% de la dosis de NPK de "dosis completa"; pero sin S, Mg y Ca). Se sembró con 90 mil semillas por hectárea en suelo con "punta de riego" el 13 de mayo en el municipio de Temascalcingo, Estado de México a 2 372 msnm. Por cuadriplicado se midieron tres grupos de variables: 1) planta en floración; 2) mazorca madura; y 3) cosecha. El cálculo de la EA fue hecho con los kilogramos de grano de maíz producidos por kg de NPK añadido al suelo; y fue por diferencias de rendimiento de grano de maíz del testigo del agricultor con cada parcela de omisión de -N, -P y -K. Las variables se analizaron con SAS y se separaron las medias con prueba de Tukey al 5%. La producción de grano se correlacionó con el índice de verdor de hoja, contenidos de nitratos y potasio en el extracto celular. Los resultados indicaron: la EA de nitrógeno fue de 20.9 kg de grano de maíz por kg de N aplicado al suelo, fósforo de 10.4 kg de grano por kg de P2O5 y potasio de 8.41 kg de grano por kg de K2O. Se correlacionó baja producción de grano de maíz a menos de 35 unidades SPAD y menos de 300 de mg L-1 de N-NO3.

The chemical composition of the essential oil from the leaves of Pelargonium odoratissimum (L.) L'Hér., Geraniaceae, was determined and the antimicrobial activities against the Aspergillus flavus CML 1816, Aspergillus carbonarius CML1815 and Aspergillus parasiticus CMLA 817 fungi, as well the Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25 992 bacteria were evaluated. The essential oil was isolated by steam distillation using a modified Clevenger apparatus, and its constituents were identified and quantified by GC/MS and GC-FID analyses. In vitro bioanalytical testing was performed using a completely randomized design. The concentrations of essential oil employed ranged from 0.1 to 2 μL.mL-1 (in dimethyl sulfoxide) for the fungus species and from 1 to 500 μL.mL-1 for the bacteria. The diameters of the inhibition zones formed for bacteria and the mean diameters of mycelial growth in perpendicular directions for fungi were measured, followed by calculation of the percentage of inhibition. The essential oil from the leaves of P. odoratissimum furnished methyleugenol (96.80%), a phenylpropanoid. This essential oil inhibited the growth of fungi (100% inhibition) and exhibited a small effect on the bacteria at the concentrations tested.

Os óleos essenciais de folhas de goiabeira Psidium guajava L. de três diferentes cultivares (Paluma, Século XXI e Pedro Sato) e da planta silvestre foram analisados a fim de comparar os seus constituintes. O óleo essencial foi obtido por hidrodestilação em aparelho de Clevenger modificado. Para a caracterização e quantificação dos compostos presentes por CG-EM e CG respectivamente. Os resultados mostraram que os três óleos essenciais analisados apresentam inúmeras substâncias em comum com a predominância do 1,8-cineol. O óleo essencial da cultivar Paluma se difere dos demais devido a alta concentração de 1,8-cineol (42,68%) e do α-terpineol (38,68%). No óleo essencial da cultivar Século XXI observase a presença do 1,8 cineol (18,83%), trans-carifileno (12,08%) e o selin-11-en-4-α-ol (20,98%) como majoritários, enquanto que a cultivar Pedro Sato e a planta silvestre apresentaram com o 1,8 cineol com (17,68%) e (12,83%), oxido de cariofileno (9,34%) e (9,09%) e o selin-11-en-4-α-ol com (21,46%) e (22,19%), respectivamente.

The compositions of the essential oils from the leaves of three domestic varieties of the guava tree Psidium guajava L. (Paluma, Século XXI and Pedro Sato) and of one wild variety were compared. Essential oils were extracted by steam distillation, the components were identified by gas chromatography coupled to mass spectrometry GC-MS, and the apparent concentrations were determined by gas chromatography with a flame ionization detector. The results demonstrated that the three essential oils contained many common substances with a prevalence of 1,8-cineole, whereas the essential oil of the Paluma variety contained 1,8-cineole (42.68%) as the major constituent, as well as α-terpineol (38.68%). The principal components of the essential oil of the Século XXI variety were 1,8-cineole (18.83%), trans-caryophyllene (12.08%), and selin-11-en-4-αol (20.98%), while those of the Pedro Sato variety and of the wild plant were 1,8-cineole (17.68%) and (12.83%), caryophyllene oxide (9.34%) and (9.09%), and selin-11-en-4-α-ol (21.46%) and (22.19%), respectively.

High copper content is of great concern among producers of sugar-cane spirits who frequently use filters instead of cleaning the stills. This study compared the efficiency of activated carbon, ion-exchange-polymeric resin, and activated-carbon/iron-oxide magnetic composite for copper reduction without removing excessive organic compounds that are important for the beverage's quality. Resin was the most efficient copper adsorbent, removing fewer organic compounds. The composite also removed copper; however, it also removed large amounts of organic compounds. Activated carbon didn't remove sufficient copper to reduce its concentration to less than 5 g L-1, and it removed large amounts of higher alcohols and esters.

Pharmacodynamic analyses were proposed to determine optimal empirical antibiotic therapy against Gram-negative bacteria isolated in a Brazilian ICU. Due to high resistance rates, standard regimens of cefepime, ciprofloxacin, meropenem, and piperacillin/tazobactam were not able to attain significant bactericidal CFR. Prolonged infusion of meropenem achieved 88% CFR, making it a possible empirical regimen in this ICU until susceptibilities become available. Still, even through administration of high dose prolonged infusions, 12.0% of simulated subjects did not achieve bactericidal exposure, suggesting that combination therapy would frequently be required in this setting. In conclusion, we recommend that in the presence of identified resistance problems among Gram-negative bacteria in a unit or hospital, MIC testing of formulary agents should be conducted along with pharmacodynamic simulation to assist in choosing an optimal antibiotic and dosage regimen for empirical use of severe infections until cultures and susceptibilities become available.

Compostos voláteis da cúrcuma (Curcuma longa L.) cultivada no Brasil foram isolados por microextração por fase sólida. Os rizomas foram cozidos em solução de bicarbonato de sódio 0,1%, fatiados, secos e triturados. Visando estabelecer o sistema ideal para a microextração, fibras de polidimetilsiloxano de 100µm de espessura foram expostas ao headspace de frascos de 10mL. Estudou-se a influência das seguintes variáveis sobre o rendimento dos compostos voláteis obtidos: amostras em pó (0,1 a 1,0g) e em solução (40mg/L), diferentes temperaturas (40 a 70ºC) e tempos (2 a 20min) de partição. O efeito da temperatura (210 a 240ºC) e do tempo (3 e 5min) de dessorção também foi avaliado. As melhores condições para a partição dos compostos voláteis foram 0,1g do pó, 70ºC e 5min. A temperatura de 220ºC e o tempo de 5 minutos foram os de maior eficiência para a dessorção. A cromatografia gasosa foi conduzida em coluna capilar, detecção por ionização de chama e identificação por espectrometria de massas. A análise dos espectros de massas obtidos para os nove compostos voláteis predominantes indicou a presença de ar-curcúmeno, ar-turmerona, zingibereno, beta-sesquifelandreno, sabineno, 1,8-cineol e 1,4-terpineol.

Volatile compounds from turmeric (Curcuma longa L.) cultived in Brazil were isolated by solid phase microextraction. The rhizomes were cooked in 0.1% sodium bicarbonate solution, sliced, dried and ground. Polydimethyldiloxanes fibers (100 mm diameter) were exposed to the headspace of 10 mL flasks with the aim of establishing an ideal microextraction system. The influence of the following parameters on the volatile substances obtained was studied: powder samples (0.1 to 1.0 g) and dissolved samples (40 mg/L), different temperatures (40 to 70ºC) and partition periods (2 to 20 min). The effect of temperature (210 to 240ºC) and time (3 to 5 min) on desorption efficiency was also evaluated. Optimum conditions for the partition of the volatiles were 0.1 g of powder sample, 70ºC and 5 min. A temperature of 220ºC and a 5 min period were of better efficiency for desorption. Gas chromatography was performed using capillary column and flame ionization detector. The eluates were identified by mass spectrometry. The mass spectra obtained for the predominant volatile compounds indicated the presence of ar-curcumene, ar-tumerone, zingeberene, beta-sesquiphellandrene, sabinene, 1,8-cineol and 1,4-terpineol.

Foram coletadas 35 amostras de mel natural em diferentes condições climáticas, por um período de dois anos. Os apiários se localizavam nos distritos de Bom Jesus do Amparo, Barão de Cocais e São Gonçalo do Rio Abaixo, a cerca de 100 km de Belo Horizonte, a capital do Estado de Minas Gerais, Brasil. As amostras foram analisadas quanto aos teores de K, Fe, Mn, Cu, Zn, espectro polínico, cor, cinzas e umidade. As médias encontradas foram: K = 1130; Mn = 3,88; Fe = 2,79; Zn = 2,34 e Cu = 0,54 µ g/g. No período de seca houve predomínio de grãos de pólen de origem de espécies de Eucalyptus e, em menor extensão de Vernonia. No período chuvoso, houve uma inversão dessa proporção. O tratamento estatístico dos resultados, separados por colméia e por estação climática, apresentou médias estatisticamente equivalentes, embora tenham sido obtidos índices expressivos de correlação (p = 0,05), como % Eucalyptus x Mn (0,450), ou entre Fe x Zn (0,698) ou ainda entre K x Mn, de 0,738.

Thirty-five natural honey samples from three apicultural regions of the state of Minas Gerais, Brazil, were collected from honeybee hives under various climatic conditions over a two-year period. The beehives were located in the districts of Bom Jesus do Amparo, Barão de Cocais and São Gonçalo do Rio Abaixo, all within a 100 km radius of Belo Horizonte, Minas Gerais, Brazil. The pollinic spectrum, color and ash, moisture, K, Fe, Mn, Cu and Zn contents were determined. Elemental analysis were done by flame atomic absorption spectrometry. Accuracy and precision were verified by recovery tests and relative standard deviation, respectively. The mean mineral contents encountered were K = 1130; Mn = 3.88; Fe = 2.79; Zn = 2.34 and Cu = 0.54 µ g/g. During the dry season, several species of Eucalyptus pollen grains predominated, with Vernonia pollen grains present in lower abundance. In the rainy season, there was an inversion of dominance. Statistical treatment of results, separated according to comb and season, showed statistically equivalent means, although some good correlation indices (p = 0.05) were obtained, e.g. between percent Eucalyptus pollen grains and Mn content (0.450), between Fe and Zn (0.698) and between K and Mn (0.738).

Alguns tipos de pães para sanduíches são sensíveis à contaminação por bolores e leveduras. Por isso a legislação brasileira de alimentos permite a adição de propionato de cálcio no limite máximo de 0,2%. A cromatografia gasosa é um método utilizado para quantificação do ácido propiônico, sendo necessária a etapa de extração desse ácido do pão que comumente se encontra sob a forma de propionato de cálcio. Foram feitos vários testes utilizando-se métodos de extração por arraste à vapor, extração etérea contendo 3% de ácido ortofosfórico e extração direta com solução aquosa de ácido fórmico 0,05 M. Foram também testadas várias colunas cromatográficas e verificado o comportamento do ácido isovalérico, ácido butírico e metil isobutil cetona (MIBK) como padrões internos. Em função dos melhores resultados obtidos, optou-se por extrair o ácido propiônico com solução etérea de ácido fórmico 3%, usando ácido butírico como padrão interno e análise cromatográfica na coluna DEGS. A recuperação média de 97,4% foi obtida com propionato de cálcio padrão e de 85,0% com amostras de pão adicionadas de propionato de cálcio. O método mostrou-se preciso, rápido e de fácil execução.

Some kinds of bread for sandwiches are susceptible to contamination by mold and yeast. Therefore, the brazilian food law allows the use of propionate salts to prevent growth of these microorganisms. The maximum level allowed is 0.2%. Gas chromatographic analysis is the method used to quantify propionic acid, which must be extracted from bread that contains these salts, usually calcium propionate. Several tests were performed, using different extraction methods such as steam distillation or extraction with ether containing 0.3% phosphoric acid or 0.05 M formic acid. Three different chromatographic columns and three different internal standards - isovaleric acid, butyric acid and isobutyl methyl ketone (MIBK) were tested. The use of a DEGS column, with butyric acid as internal standard and extraction of propionic acid with 3% formic acid in ether was chosen. The recovery of calcium propionate from a standard solution by this method was 97.4%, while that obtained with samples of bread spiked with this salt was 85%. This method was found to be rapid, precise and easy to execute.