Persistence of trifloxystrobin and tebuconazole in banana tissues and soil under the semi-arid climatic conditions of Karnataka,India

Trifloxystrobin and tebuconazole are used for control of Sigatoka leaf spot disease of banana. This study was conducted to evaluate residue persistence of the fungicides in/on banana fruit, other edible parts and soil after spray application of the combination formulation, Nativo 75 WG, at the standard dose, 87.5 + 175 and double dose, 175 + 350 g a.i. ha^?1. The fungicides were extracted from banana and soil with acetone, partitioned into dichloromethane and cleaned-up using activated charcoal for trifloxystrobin and primary/secondary amine (PSA) for tebuconazole samples. The limit of quantification of the method was 0.05 mg kg^?1 for both fungicides. Initial residues of trifloxystrobin were 0.444 and 0.552 mg kg^?1 in/on banana with peel (whole fruit), which reached <0.05 and 0.065 mg kg^?1 after 30 days from treatment at the standard and double doses, respectively. Tebuconazole residues were 0.636 and 960 mg kg^?1 initially and reduced to 0.066 and 0.101 mg kg^?1 after 30 days. Trifloxystrobin and tebuconazole degraded with the half-life of about 11 days. Trifloxystrobin or its metabolite was not detected in the fruit pulp. Tebuconazole being systemic in nature moved to the fruit pulp which was highest on the 3rd day (0.103 and 0.147 mg kg^?1) and remained for 15 days. Matured banana fruit, flower, pseudostem and field soil were free from fungicide residues. For consumption of raw banana 43 days pre-harvest interval (PHI) is required after treatment of the combination formulation. Therefore application of the fungicides towards maturity stage of the fruits may be avoided.     

Synthesis of solar active nanocrystalline ferrite, MFe2O4 (M: Ca, Zn, Mg) photocatalyst by microwave irradiation

For the first time, nanocrystalline photocatalysts of spinel MgFe₂O₄, ZnFe₂O₄ and orthorhombic CaFe₂O₄ oxides were synthesized (at low temperature ∼973 K) by microwave sintering, in one sixtieth of the time required to that of the conventional method. A significantly improved crystallinity was obtained for the samples irradiated for longer duration of time (∼10-100 min). The theoretically computed electronic structure of the MFe₂O₄ (M: Ca, Zn, Mg) systems was respectively correlated with the experimental results obtained from their structural and photocatalytic characterization. The photocatalytic performance was found to be affected by surface area and crystallinity of the photocatalyst. The density functional theory (DFT) calculations of MFe₂O₄ lattices revealed that M-ion controllably affects the density of sates of the Fe-d orbitals near the Fermi level. Consequently they play an important role in determining the band-energetics and thus the visible light photocatalytic activity for methylene blue degradation.     

Exergy and energy performance for wavy fin radiator with a new coolant of various shape nanoparticle-based hybrid nanofluids

Journal of Thermal Analysis and Calorimetry - Energetic and exergetic performance for an automotive radiator with wavy fin configuration has been investigated and compared for water-based 1% vol....     

The relativistic two- and three-quark problems

For theqqq problem, the corresponding covariant-instantaneity-ansatz dynamics is formulated through the introduction of new Lorentz-invariant momenta, which again are closely parallel to the older null-plane-ansatz treatment for the same on a two-tier basis, but facilitate a derivation of the 3-dimensional Bethe-Salpeter equation in a more general form for unequal-mass kinematics than seem to have been attempted previously.     

Emission from an excited triplet state during ECL

The application of Marcus theory of electron transfer reactions for the case of radical ion chemiluminescence of 9,10-diphenylanthracene (DPA) gives a high rate constant value (10⁹–10¹⁰ M^?1 s^?1) for the formation of the second triplet state (T₂). It is suggested that the near infrared emission observed during electrochemiluminescence of DPA is due to T₂ → T₁ fluorescence based on the high yield of T₂ (≈0.7) in the electron transfer reaction.     

Biomolecules and Nutritional Quality of Soymilk Fermented with Probiotic Yeast and Bacteria

Soymilk was fermented with five isolates of probiotic lactic acid bacteria and in combination with probiotic yeast Saccharomyces boulardii. Nutritional profile like fat, protein, ash, pH, acidity, polyphenol, and protein hydrolysis were analyzed. Polyphenol content decreased from 265.88 to 119 microg/ml with different cultures. Protein hydrolysis ranged from 2.46 to 2.83 mmol l(-1) with different cultures. The antioxidant activity was assessed using different methods like 1, 1-diphenyl-2-picrylhydrazyl free radical-scavenging assay, inhibition of ascorbate autoxidation, and measurement of reducing activity. The activities varied with the starters used but, nevertheless, were significantly higher than those found in unfermented soymilk. Bioconversion of the isoflavone glucosides (daidzin + genistin) into their corresponding bioactive aglycones (daidzein + genistein) was observed during soymilk fermentation. Total glucosides in soyamilk were 26.35 mg/100 ml. In contrast, aglycones genistein and daidzein were quantitatively lesser accounting 2.91 mg/100 ml (genistein 1.17 mg/100 ml and daidzein 1.19 mg/100 ml). Soymilk fermented with probiotic cultures resulted in the reduction of glycosides ranging from 0.40 mg to 1.36 mg/100 ml and increase in aglycones ranging from 6.32 mg to 13.66 mg/100 ml.     

A statistical approach using L<Subscript>25</Subscript> orthogonal array method to study fermentative production of clavulanic acid by <Emphasis Type="Italic">Streptomyces clavuligerus</Emphasis> MTCC 1142

Clavulanic acid is a naturally occurring antibiotic produced by Streptomyces clavuligerus. The present work reports on clavulanic acid production by Streptomyces clavuligerus MTCC 1142 using one-factor-at-a-time and L₂₅ orthogonal array. The one-factor-at-a-time method was adopted to investigate the effect of media components (i.e., carbon source, nitrogen source and inoculum concentration) and environmental factors such as pH for clavulanic acid production. Production of clavulanic acid by Streptomyces clavuligerus was investigated using seven different carbon sources (viz. glucose, sucrose, modified starch, rice-bran oil, soybean oil, palm oil, and glycerol) and six different nitrogen sources (viz. peptone, yeast extract, ammonium chloride, ammonium carbonate, sodium nitrate and potassium nitrate). A maximum yield of 140 μg/mL clavulanic acid was obtained in the medium containing soybean oil as a carbon source and yeast extract as nitrogen source. Subsequently, the concentration of soybean flour, soybean oil, dextrin, yeast extract and K₂HPO₄ were optimized using L₂₅ orthogonal array method. The final optimized medium produced 500 μg/mL clavulanic acid at the end of 96 h as compared to 140 μg/mL before optimization. Synthesis of precursor molecules as a metabolic driving force is of considerable importance in antibiotic synthesis. Attempts to increase the clavulanic acid synthesis by manipulating the anaplerotic flux on C₃ and C₅ precursors by supplementing the medium with arginine, ornithine, proline, valine, leucine, isoleucine, pyruvic acid and á-ketoglutarate were successful. Supplementing the optimized medium with 0.1 M arginine and 0.1 M leucine increased the yield of clavulanic acid further to 1100 μg/mL and 1384 μg/mL respectively.     

Isolation and synthesis of pygmanilines,phenylurea derivatives from the Northeastern Atlantic lichen Lichina pygmaea

A library of 864 extracts prepared from Irish marine organisms was screened in the search for novel antioxidants. Chemical investigation of the most promising extract obtained from the common lichen Lichina pygmaea led to the isolation of five resorcinol derivatives. An unusual urea moiety was found embedded in two of these compounds, pygmanilines A (1) and B (2) and their structures were confirmed by one-step chemical syntheses.