Biomass Sorghum: Effect of Acid, Basic and Alkaline Peroxide Pretreatments on the Enzymatic Hydrolysis and Ethanol Production

Abstract This study evaluated the effects of three chemical pretreatments of biomass sorghum (BS): dilute alkaline (PTA1 and PTA2), dilute acid (PTB1 and PTB2) and alkaline hydrogen peroxide (PTC1 and PTC2) in the enzymatic hydrolysis and ethanol production. Among the six investigated conditions, the pretreatment with 7.36% H2O2 (PTC2) was the most efficient in the lignin removal and preservation of the polysaccharide fraction. After the enzymatic hydrolysis, increases in the glucose and xylose concentrations were observed in the pretreated BS hydrolysates, mainly in PTB1 and PTC1. All the hydrolysates obtained low concentrations of inhibitors. In the alcoholic fermentations with Pichia stiptis, the greatest ethanol yield was obtained in PTB1 hydrolysate (3.84 g L-1), corresponding to 16.15% of yield. The highest ethanol yield in PTB1 hydrolysate can be justified by the maximum concentration of xylose obtained in this hydrolysate, demonstrating the potential of P. stiptis in the fermentation of pentose to ethanol. The results indicated that biomass sorghum is an alternative lignocellulose source with potential for the production of second generation ethanol, opening up prospects for additional studies.

Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters

ABSTRACT This study investigated the anesthetic potential of the essential oil (EO) of Aloysia polystachya in juveniles of dusky grouper (Epinephelus marginatus). Fish were exposed to different concentrations of EO of A. polystachya to evaluate time of induction and recovery from anesthesia. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 µL L−1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na+ and K+ levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 µL L−1. However, most evaluated blood parameters showed compensatory responses due to EO exposure.

Effect of evaporation and pasteurization in the biochemical and immunological composition of human milk

OBJETIVO: Avaliar os efeitos da evaporação e da pasteurização do leite humano na sua composição bioquímica e imunológica e em sua osmolaridade. MÉTODOS: As amostras de leite humano maduro foram divididas em quatro grupos de estudo: leite humano in natura, leite humano pasteurizado, leite humano evaporado a 70 por cento do volume inicial e leite humano pasteurizado e evaporado a 70 por cento, com 12 diferentes amostras de leite em cada grupo. Das amostras dos grupos, foram dosadas as concentrações de sódio, potássio, cálcio, fósforo, magnésio, proteína, gordura, lactose, imunoglobulina A e osmolaridade. RESULTADOS: A pasteurização do leite humano não mostrou alterações estatisticamente significantes na concentração dos elementos sódio, potássio, cálcio, fósforo, magnésio, proteína, gordura, lactose, nem na osmolaridade; no entanto, mostrou redução significante na concentração média de imunoglobulina A. A evaporação mostrou aumento estatisticamente significativo de 38 por cento em média na concentração dos elementos sódio, potássio, cálcio, fósforo, magnésio, proteína, gordura e lactose e redução média de 45 por cento na concentração da imunoglobulina A, sem alteração significativa da osmolaridade em relação ao leite sem processamento. CONCLUSÃO: Através da evaporação a 70 por cento do volume inicial do leite humano, pode ser obtido leite humano com condições de satisfazer as necessidades nutricionais preconizadas para o recém-nascido pré-termo, com exceção do cálcio e do fósforo.

OBJECTIVE: To assess the effects of evaporation and pasteurization of human milk on its biochemical and immunological composition and on its osmolarity. METHODS: The samples of mature human milk were categorized into four study groups: in natura human milk, pasteurized human milk, human milk evaporated at 70 percent of the baseline volume and human milk pasteurized and evaporated at 70 percent, with 12 different samples of milk in each group. The samples were used to determine the concentrations of sodium, potassium, calcium, phosphorus, magnesium, protein, fat, lactose, immunoglobulin A and osmolarity. RESULTS: The pasteurization of human milk did not show statistically significant changes in the concentration of sodium, potassium, calcium, phosphorus, magnesium, protein, fat, lactose, or in osmolarity; however, it showed remarkable reduction in the mean concentration of immunoglobulin A. Evaporation had a mean increase of 38 percent in the concentration of sodium, potassium, calcium, phosphorus, magnesium, protein, fat and lactose and mean reduction of 45 percent in the concentration of immunoglobulin A, without significant change in osmolarity in unprocessed milk. CONCLUSION: By evaporation at 70 percent of the baseline value of human milk, it is possible to obtain human milk that meets the nutritional requirements recommended for preterm infants, except for calcium and phosphorus.

Influence of the alkali metal cation on the fragmentation of monensin in ESI-MS/MS

The MS/MS fragmentation of the alkali metal complexes of monensin A are studied. The increase in alkali metal ionic radii decreases the ability of the Grob-Wharton fragmentation mechanism to occur and reduces the overall degree of fragmentation. Conversely, the electronegativity of the metal cation is related to the number of fragment ions observed.

O presente trabalho relata os estudos de fragmentação por espectrometria de massas seqüencial de complexos formados pela monensina A e uma série de metais alcalinos. Foi observado que o aumento do raio iônico do metal alcalino levou a uma diminuição do mecanismo de fragmentação do tipo Grob-Wharton e ao grau de fragmentação. Por outro lado, a maior eletronegatividade mostrou estar relacionada ao número de fragmentos observados.

Concentraciones de calcio, magnesio, sodio y potasio en leche materna y fórmulas de inicio / Concentrations of calcium, magnesium, sodium and potassium in human milk and infant formulas

Concentrations of calcium, magnesium, sodium and potassium were determined in 55 samples of mature human milk from Canary women and 5 samples of powdered infant formula. According to the literature our data fell within the normal intervals described for each kind of milk. The mean concentration of Ca, Mg, Na y K of powdered infant formula was higher than those concentrations found in the human milks. Significant differences among the concentrations of Ca, Mg and Na for the milks of the considered mothers were observed. Only the Ca intakes for infants fed with human milk were lower than those requirements recommended by the Food and Nutrition Board (1989). However, the infants fed with powdered infant formula had an adequate intake of all the studied metals. A progressive decrease of the Na, K and Ca concentrations with the lactation stage was observed. Maternal age, parity and sex of the newborns did not affect the metal concentrations significantly.

Quemaduras por agentes químicos / Chemical burns

Se realiza una revisión de la literatura nacional e internacional sobre quemaduras químicas. En primer término se describen las causas, la fisiopatología de las quemaduras y se presenta una clasificación de los compuestos químicos corrosivos que al ponerse en contacto con la piel general quemaduras químicas. Se destacan los ácidos inorgánicos, ácidos orgánicos, compuestos alcalinos y compuestos específicos que, por la naturaleza y gravedad de las lesiones que producen, requieren de una presentación individual, tales como el fósforo y el tetracloruro de titanio. A continuación se describen las medidas generales iniciales de tratamiento para toda quemadura química y algunas medidas especiales para corrosivos específicos de alta peligrosidad. Luego se definen las medidas de tratamiento local secundario. Por último, se incluye un párrafo especial para el manejo de las quemaduras oculares por agentes corrosivos. Al cierre, se destaca la necesidad de desarrollar una política educativa de prevención en el manejo de productos corrosivos como el mejor método par reducir la incidencia de lesiones graves

Electrical conductance studies of alkali metal acetate in anhydrous acetic acid solutions

Conductance studies of alkali metal acetates in glacical acetic acid as reported in the literature are few [1] Most of these investigators, gave some kinds of scattered values regarding the conductance of one or two salts at certain temperature. Neither the value of the limiting conductance nor the ion-pair dissociation constant could be evaluated from their data except only those values of Jones and Griswold [2]]who derived the values of limiting molar conductance and ion-pair dissociation constant at 30 degree. An extrapolation approach of conductance concentration data to evaluate the limiting molar conductance as well as the ion-pair dissociation constant had been suggested in various methods[3-5] In the present study, it is aimed to investigate systematically the conductance of some alkali inorganic salts [Li, Na and K acetates] in a low dielectric constant solvent

Potentiometric titration of carboxyalkylated poly vinyl alcohol with mono-, di-, and trichloroacetic acids with alkali metal hydroxides and quaternary ammonium bases

Potentiometric titrations of the products obtained by polyvinyl alcohol first carboxyalkylated with chloroacetic acids were conducted with LiOH, NaOH, KOH, NH4OH, N[CH3]4OH and N[C2H5]4OH in deionized water, and with mixtures of LiOH and tetraethylammonium hydroxide of varying proportions. The results were expressed in terms of the modified Henderson-Hasselbach equation pH = pKa-n log [[1-alpha]/alpha]. Appreciable shifts in the titration curves to lower pH values were observed, accompanied by increase of the calculated capacity of the polyelectrolyte, in the sequence N[C2H5]4OH < N[CH3]4OH < NH4OH < KOH < LiOH. The values of pKa [at alpha = 0.5] where alpha is the degree of neutralization and is found to increase with the size of counterion. The titration curves obtained with mixture of LiOH and N[C2H5]4OH showed that the calculated values of capacity and the position of the curves were intermediate between those obtained with solutions of the single cations