Evaluation of a modified QuEChERS extraction of multiple classes of pesticides from a rice paddy soil by LC-APCI-MS/MS

A new method for the determination of clomazone, fipronil, tebuconazole, propiconazole, and azoxystrobin in samples of rice paddy soil is presented. The extraction of the pesticides from soil samples was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Some extraction conditions such as salt addition, sample acidification, use of buffer, and cleanup step were evaluated. The optimized method dealt with a single extraction of the compounds under study with acidified acetonitrile, followed by the addition of MgSO(4) and NaCl prior to the final determination by liquid chromatography-atmospheric chemical pressure ionization-tandem mass spectrometry. Validation studies were carried out in soil samples. Recoveries of the spiked samples ranged between 70.3 and 120% with relative standard deviation lower than 18.2%. The limits of quantification were between 10 and 50 μg kg(-1). The method was applied to the analysis of real samples of soils where rice is cultivated.     

Lidocaine effects on corneal endothelial cell ultrastructure

The purpose of this study was to determine whether intracameral commercial lidocaine 2% induces alterations on the rabbit corneal endothelium. Forty white rabbits received different substances inside the anterior chamber: group (G)1, no substance; G2 and G3 received lidocaine 2% with preservative in aqueous solution; G4 and G5, lidocaine 2% with preservative in gel solution; G6 and G7, the anesthetic preservative (metilparahydroxybenzoate 0.1%); and G8 and G9, lidocaine 2% without preservative in aqueous solution. The animals from G2, 4, 6 and 8 were sacrificed after 1 h, and from G3, 5, 7 and 9 after 24 h after injection of the substance inside the anterior chamber. The corneas were clinically evaluated and assessed by transmission and scanning electron microscopy. G1, 2, 6, 7, 8 and 9 animals had very similar characteristics in clinical, ultrastructural and morphometric evaluations; the G3 and G4 animals showed discrete edema and one animal in G5 had intense corneal edema. We conclude that lidocaine 2% with preservative induces few ultrastructural alterations in the corneal endothelial cells.     

New Insights of Turmeric Extract-Loaded PLGA Nanoparticles: Development,Characterization and In Vitro Evaluation of Antioxidant Activity

Here, we presented new insights of the development of poly(lactic-co-glycolic acid) nanoparticles containing turmeric compounds (turmeric-PLGA-NPs) using emulsion-solvent evaporation method. The nanoparticulate system was characterized by size, zeta potential, morphology, release profile, partition parameter, stability and encapsulation efficiency (%EE). Antioxidant activity studies were also evaluated. The Korsmeyer-Peppas model (M_t/M_∞ vs. t) was used to determine the release mechanisms of the studied system. Our results demonstrated the emulsion-solvent evaporation method was shown advantageous for producing turmeric-PLGA-NPs in the range of 145 nm with high homogeneity in size distribution, zeta potential of ?21.8 mV and %EE about 72%. Nanoparticles were stable over a period of one month. In vitro study showed a release of curcumin governed by diffusion and relaxation of the polymeric matrix. The partition parameter of the extract in relation to blank-PLGA-NPs was 0.111?±?0.008 M^?1, indicating a low affinity of curcumin for the polymer matrix. Antioxidant ability of the turmeric-PLGA-NPs in scavenging the radical 2,2-azinobis (3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS) was inferior to free turmeric extract and showed a concentration and time-dependent profile. The study concluded that PLGA nanoparticles are potential carriers for turmeric extract delivery.

     

Globulin and albumin proteins in dehulled seeds of three Phaseolus vulgaris cultivars

Albumin and globulin fractions, obtained after modifications of the Osborne's fractionation scheme, were investigated in the seeds of three cultivars of Phaseolus vulgaris, after removal of the seed coats, to prevent interactions of tannins and phenols with the globulins. Also, by using an appropriate buffer to separate the globulins more efficiently, no cross-contaminations were observed in SDS-PAGE between these two fractions. The combination of these two procedures resulted in globulin to albumin ratios 70percnt higher than those published previously with the same cultivars. Amino acid compositions of total globulin, phaseolin and albumin fractions are presented. Whereas the albumins contained much more cysteine than the globulins, the concentrations of methionine were evenly distributed in these two fractions. Also, the bulk of methionine was found in phaseolin; cysteine was found in non-phaseolin proteins. In addition, the globulins contained unexpectedly high amounts of lysine.     

Chemical Composition and Bile Acid Binding Activity of Products Obtained from Amaranth (<Emphasis Type="Italic">Amaranthus cruentus</Emphasis>) Seeds

Cardiovascular diseases are currently the greatest cause of mortality in the world, and dislipidemia is appearing as one of the most important risk factors. The binding of bile acids (BAs) has been hypothesized as a possible mechanism by which dietary fibers lower blood cholesterol levels. Besides the fibers, other components in the amaranth seeds may be related to this hypocholesterolemic effect. The objective of the present study was to evaluate the BA binding capacity of some products obtained from defatted amaranth flour (DAF) and from the amaranth protein concentrate (APC). The alkaline residue, rich in fibers (8.6%), presented the lowest binding activity for the BAs tested, with the exception of glycocholic acid. The DAF showed intermediary binding activity for all the BAs tested, although similar to that of the APC for deoxycholic acid, and to that of the amaranth protein hydrolysate (APH) for taurocholic acid. The DAF and APC showed binding activity for secondary bile acids toxic to the intestinal mucus. From the results, amaranth products were shown to have the ability to bind BAs, but it was not possible to affirm whether the main component responsible for this activity was the proteins, fibers or eventually some other non-evaluated component.     

Soybean drought-stressed plants impair Anticarsia gemmatalis (Lepidoptera: Erebidae) midgut proteolytic activity and survival

Phytoparasitica - Soybean plants are exposed to multiple stresses during development. Co-occurring stresses can activate common defense pathways on plants, increasing end products concentrations,...     

The Correlation between Age,Body Weight and Testicular Parameters in Murrah Buffalo Bulls Raised in Brazil

Buffalo are an economically important source for meat and milk production, especially in Brazil. However, important aspects of their biology remain unknown thus far. Herein, we describe the reproductive characteristics of male Murrah buffalo (Bubalus bubalis) raised under extensive management conditions by applying biometrics associated with testicular weight. We analyzed seven males, divided into two groups: G1, which consisted of four 18-month-old animals, and G2, which consisted of three 24-month-old animals. Testicular development occurs slowly in Murrah buffalo, suggesting a delay of sexual maturity. The biometric testicular parameters analyzed were scrotal circumference, testicular weight, testicular length, testicular width, testicular thickness and testicular circumference. Our data indicate strong correlations between SC, age and body weight, and additional significant relationships were identified between body weight, age and other testicular parameters. Thus, these parameters are suitable indicators when selecting bulls for breeding purposes.     

Nitrogen supply associated with rhizobacteria in the first productive cycle of Marandu grass

Journal of Crop Science and Biotechnology - The rhizobacteria of genus Azospirillum and Bacillus are effective at fixing atmospheric nitrogen, promote plant growth and can largely contribute to...     

The Prospective Use of Brazilian Marine Macroalgae in Schistosomiasis Control

Schistosomiasis is a parasitic disease that affects more than 250 million people. The treatment is limited to praziquantel and the control of the intermediate host with the highly toxic molluscicidal niclosamide. Marine algae are a poorly explored and promising alternative that can provide lead compounds, and the use of multivariate analysis could contribute to quicker discovery. As part of our search for new natural compounds with which to control schistosomiasis, we screened 45 crude extracts obtained from 37 Brazilian seaweed species for their molluscicidal activity against Biomphalaria glabrata embryos and schistosomicidal activities against Schistosoma mansoni. Two sets of extracts were taxonomically grouped for metabolomic analysis. The extracts were analyzed by GC–MS, and the data were subjected to Pattern Hunter and Pearson correlation tests. Overall, 22 species (60%) showed activity in at least one of the two models. Multivariate analysis pointed towards 3 hits against B. glabrata veliger embryos in the Laurencia/Laurenciella set, 5 hits against B. glabrata blastula embryos, and 31 against S. mansoni in the Ochrophyta set. Preliminary annotations suggested some compounds such as triquinane alcohols, prenylated guaianes, dichotomanes, and xenianes. Despite the putative identification, this work presents potential candidates and can guide future isolation and identification.     

Environmental Behaviour of Metolachlor and Diuron in a Tropical Soil in the Central Region of Brazil

The environmental behaviour of metolachlor and diuron was studied in the Central-western region of Brazil, by means of a field study where six experimental plots were installed. The soil was classified as a Latosol, and the soil horizons were characterized. Sorption of metolachlor and diuron was evaluated in laboratory batch experiments. Metolachlor and diuron were applied to the experimental plots on uncultivated soil in October 2003. From this date to March 2004, the following processes were studied: leaching, runoff and dissipation in top soil. K _oc of metolachlor varied from 179 to 264 mL g^?1 in the soil horizons. K _oc of diuron in the Ap horizon was 917 mL g^?1, decreasing significantly in the deeper horizons. Field dissipation half-lives of metolachlor and diuron were 18 and 15 days, respectively. In percolated water, metolachlor was detected in concentrations ranging from 0.02 to 2.84 μg L^?1. In runoff water and sediment, metolachlor was detected in decreasing concentrations throughout the period of study. Losses of 0.02% and 0.54% of the applied amount by leaching and runoff, respectively, were observed confirming the high mobility of this herbicide in the environment. In percolated water, diuron was detected with low frequency but in relatively high concentrations (up to 6.29 μg L^?1). In runoff water and soil, diuron was detected in decreasing concentrations until 70 days after application, totalizing 13.9% during the whole sampling period. These results show the importance of practices to reduce runoff avoiding surface water contamination by these pesticides, particularly diuron.