Synthesis and expansion of bicyclic enol ether: a probable precursor for the synthesis of macrolide (±)-pyrenophorin

A convenient procedure for the synthesis and expansion of bicyclic rings has been developed for the production of probable precursors of non-racemic pyrenophorin, an antibiotic dilactone. The major highlight for this new synthetic methodology came from the use of a readily available reagent of easy manipulation, 9-oxabicyclo[3.3.1]nonane-2,6-diol, for the preparation of the bicyclic intermediate, which sequentially was subjected to oxidative cleavage with butyl nitrite resulted in an isomeric mixture, a dioximedilactone and diisoxazoledilactone

Absence of ferromagnetic order in high quality bulk Co-doped ZnO samples

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Bulk Zn(1-x)Co(x)O samples were synthesized via standard solid-state reaction route with different Co molar concentrations up to 21%. A detailed microstructural analysis was carried out to investigate alternative sources of ferromagnetism, such as secondary phases and nanocrystals embedded in the bulk material. Conjugating different techniques we confirmed the Zn replacement by Co ions in the wurtzite ZnO structure, which retains, however, a high crystalline quality. No segregated secondary phases neither Co-rich nanocrystals were detected. Superconducting quantum interference device magnetometry demonstrates a paramagnetic Curie-Weiss behavior with antiferromagnetic interactions. We discuss the observed room temperature paramagnetism of our samples considering the current models for the magnetic properties of diluted magnetic semiconductors. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3459885]1083FAPEMIGConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPEMIG_BrasilCNPq_BrasilFAPESP_Brasi

Optical characterization of 316L stainless steel coated with sol-gel titania

In this work 316L stainless steel substrates were coated with sol-gel derived films by means of the dip-coating technique. Titanium isopropoxide and ethanol were used as chemical precursor and solvent, respectively. The dip-coating step was performed using withdrawal speeds of 6 mm/min, 30 mm/min, and 60 mm/min. Next, the samples were heat treated in air for 30 min at 100 °C, 300 °C, and 400 °C. The processed composites were examined by FTIR and UV-vis spectroscopies. We observed that the materials prepared in this work can exhibit a variety of colors depending on the heat treatment temperature, withdrawal speed, and precursor:solvent molar ratio used in their processing. It is an important finding since this behavior could lead to architectural application of these materials. We believe that the changes observed in the UV-vis spectra and the colors of these samples could be related to the variation of the coating thickness as the processing conditions were modified. FTIR tests revealed that the ratio between the intensities of features ascribed to hydroxyl groups and TiO bonds decreased as the heat treatment temperature was increased. On the other hand, the ratio between bands related to TiOTi and TiO bonds decreased when the heating temperature was raised from 100 °C to 300 °C

Partial substitution of fishmeal with soybean protein-based diets for dourado Salminus brasiliensis.

Cost and environmental restrictions limit the use of fishmeal (FM) in aquafeeds and plant protein (PP) sources. Soybean by-products are important alternative; however, their antinutritional factors may reduce fish growth. This study evaluates the effect of FM substitution for PP (soybean meal and soy protein concentrate) in diets of dourado (Salminus brasiliensis), a promising species for fish farming and empirically considered highly tolerant to PP-based diets. A control diet was formulated to contain 20 % of fishmeal and 61 % of plant protein (SBM) and other five diets with decreasing FM graded levels (16 %, 12 %, 8 %, 4 %, 0 %), which were replaced by soybean protein concentrate (SPC), comprising six treatments and four replicates. Fifteen dourados (6.73 ± 0.2 g) were stocked into 200 L tanks in a recirculating system, fed with experimental diets three times a day to apparent satiation for 90 days. Growth performance, food conversion ratio, protein efficiency ratio and protein retention efficiency of fish were impaired when FM substitution exceeded 13.05 % (the broken line analysis method). Histological analysis of intestinal mucosa showed a decrease in villus height when fishmeal was totally replaced by PP, which probably impaired digestive functions of fish and reflected in a severe loss on growth performance

Natural Horse Boarding Vs Traditional Stable: A Comparison of Hormonal, Hematological and Immunological Parameters, Journal of Applied Animal Welfare Science,

In the equestrian world, two different types of management can be distin-guished: traditional management and natural boarding. The aim of this researchwas to compare hormonal, hematological and immunological parameters of 47horses kept in these two different managements. Blood and horsehair of thehorses were sampled to determine DHEA (dehydroepiandrosterone) and cortisolconcentration through RIA. Moreover, blood count was conducted, and flowcytometry was employed to phenotype lymphocyte subpopulations. Resultsshowed that, in horsehair, DHEA concentration was significantly higher innatural horses, whereas cortisol concentration and cortisol/DEHA ratio signifi-cantly lower. These hormonal parameters are used to assess the stress conditionand the welfare of animals. The most favorable endocrine framework found inhorses kept in natural boarding suggests that this management conveys mostwith ethological and physiological needsof the species. The research underlinesthe need of a modification of horses\u2019husbandry systems. For the first time, thisstudy validates the assay of DHEA in horsehair