Influência da temperatura de secagem sobre o rendimento e a composição química do óleo essencial de Tanaecium nocturnum (barb. Rodr.) bur. & K. Shum

The yields and chemical compositions of the essential oils obtained by steam distillation of the fresh and dried (30 and 40 ºC) leaves, stems and roots of Tanaecium nocturnum are reported. The identification and quantification of the volatile constituents were accomplished by GC/MS and GC/FID, respectively. The essential oils obtained from the various parts of the plant were constituted mainly of benzaldehyde. Large losses and variations in the quantities of the components during the drying process were observed. The presence of mandelonitrile in higher concentration in the stem and roots indicates that this species produces cyanogenic glycosides.

Energian käyttö sahatavaran kuivauksessa

Sahatavaran tuotannossa käytetään runsaasti lämpöä ja sähköä. Sähköä käytetään pääasiassa sahausvaiheessa ja lämpöä kuivausvaiheessa. Sahatavarakuutiosta haihdutetaan vettä kuivaamoissa noin 230-600 kiloa. Sahatavara kuivataan, koska kuivattu sahatavara säilyy paremmin ja on lisäksi kevyempää, kestävämpää ja sen muodonmuutokset ovat pienempiä. Työssä käsiteltävällä sahalla on erääseen kanavakuivaamoon tehty koerakennelma, jonka avulla kuivaamosta poistettavan ilman sisältämää lämpöä hyödynnetään sahatavaran lämmittämisessä kuivauslämpötilaan kuormanvaihdon jälkeen. Energiansäästön lisäksi rakennelman toivotaan ehkäisevän kuormanvaihdosta aiheutuvia olosuhdemuutoksia kuivausprosessin muissa vaiheissa. Poistoilman sisältämä höyry lauhtuu lämmittäessään kylmää sahatavaraa. Lauhtumisen yhteydessä vapautuu runsaasti energiaa. Tehtyjen kokeiden perusteella koerakennelma vähensi lämmönkulutusta selvästi. Lämmönkulutuksen alenema oli jopa teorialaskelmaa suurempi, mistä syystä kokeellisessa osassa tehtyihin mittaustuloksiin on syytä suhtautua varauksella. Perinteisessä kuivaamossa kosteus poistuu pääasiassa vesihöyrynä, mutta koerakennelman avulla saadaan noin puolet puusta haihdutetusta vedestä lauhtumaan takaisin vedeksi.

Micropartículas nanorrevestidas contendo um fármaco modelo hidrofóbico: preparação em etapa única e caracterização biofarmacêutica

The aim of this work was to prepare and characterize spray-dried nanocapsule-coated microparticles obtained in one step, using indomethacin as a hydrophobic drug model and poly(e-caprolactone) or Eudragit® RS100, as polymers. Nanocapsule-coated microparticles showed micrometric mean sizes (10 - 15 µm) and a reduced surface area (75 - 85 m²g-1) compared to the raw material (214 m²g-1). Microparticles coated with Eudragit® RS100-nanocapsules showed a better control of the drug release. The release profiles fit to the monoexponetial model and to the Power Law. The mechanism of the indomethacin release from the microparticles is non-Fickian and depends on the particles desagglomeration.

Improvement of genistein content in solid genistein/-cyclodextrin complexes β

Genistein:β-cyclodextrin complexes with high drug loading (19.22%) were prepared by freeze-drying and characterized by differential scanning calorimetry and hydrogen nuclear magnetic resonance spectroscopy. The spatial configuration of the complex was proposed by means of 2D-NOESY experiment combined with molecular modeling. According to the results obtained, the interaction of genistein with β -cyclodextrin in a 1:1 complex is supposed to occur mainly through the insertion of the guest A-ring in cyclodextrin cavity, without rule out the possibility of inclusion through the B-ring, as previously reported in the literature.

Evaluation of sample processing methods for the polar contaminant analysis of sewage sludge using liquid chromatography - mass spectrometry (LC/MS)

Monitoring of sewage sludge has proved the presence of many polar anthropogenic pollutants since LC/MS techniques came into routine use. While advanced techniques may improve characterizations, flawed sample processing procedures, however, may disturb or disguise the presence and fate of many target compounds present in this type of complex matrix before analytical process starts. Freeze-drying or oven-drying, in combination with centrifugation or filtration as sample processing techniques were performed followed by visual pattern recognition of target compounds for assessment of pretreatment processes. The results shown that oven-drying affected the sludge characterization, while freeze-drying led to less analytical misinterpretations.

Caracterização dos níveis de elementos químicos em solo, submetido a diferentes sistemas de uso e manejo, utilizando espectrometria de fluorescência de raios-x por energia dispersiva (EDXRF)

This study aimed to evaluate the chemical elements levels in soil, submitted to different management systems and use by the Energy Dispersive X-Ray Fluorescence Spectrometry - EDXRF. The systems were T1 - agro forestry (SAF), T2 - Native Field (CN), T3 - Native Forest (NM), T4 - Tillage Forest (PF); T5 - conventional tillage system (SPC) and T6 - System tillage (NT). Samples were collected at 0-10 and 10-20 cm, dried and ground for analysis in EDX-720. The soil showed no difference in the average concentrations of chemical elements analyzed in the profiles, but the systems presented different concentrations of metal elements, and T3 had the highest K, Ca and Zn at 0-10 cm and higher contents of K, Ca, Cu, Zn and Mn in the layer of 10-20 cm.

A green synthesis of α,β-unsaturated carbonyl compounds from glyceraldehyde acetonide

The catalytic behavior of Cs-exchanged and Cs-impregnated zeolites (X and Y) was studied using the Knoevenagel condensation between glyceraldehyde acetonide and ethyl acetoacetate in order to produce the corresponding α,β-unsaturated carbonyl compound that is an important intermediate for fine chemicals. The influence of reaction temperature, type of zeolite, and basicity of the sites on the catalytic behavior of the samples was evaluated. All zeolites were active for the studied reaction. The formation of the main condensation product was favored at lower reaction temperatures. Products of further condensations were also observed especially for samples that were only dried before catalytic test.

Planejamento experimental na otimização da extração dos frutos de Syzygium cumini (L.) skeels

The aim of this study was to standardize the extractive solution of Syzygium cumini. The extractive solution was selected through a full factorial design, considering the extraction method (maceration-5-days, turbo extraction, percolation), extractor solvent (ethanol 50, 70, 96%) and plant material particle size 0.302 mm into a plant:solvent ratio (1:10), using the dried residue and antimicrobial activity determination as evaluation criteria. The tests were performed in triplicate. It appeared that the percolation is the best procedure extractive, and ethanol mixture: water (50:50) the best solvent. ANOVA analysis showed the importance of these parameters.

Homogeneous Assays for Simplified Screening of HLA-conferred Genetic Disease Risk

The increasing incidence of type 1 diabetes has led researchers on a quest to find the reason behind this phenomenon. The rate of increase is too great to be caused simply by changes in the genetic component, and many environmental factors are under investigation for their possible contribution. These studies require, however, the participation of those individuals most likely to develop the disease, and the approach chosen by many is to screen vast populations to find persons with increased genetic risk factors. The participating individuals are then followed for signs of disease development, and their exposure to suspected environmental factors is studied. The main purpose of this study was to find a suitable tool for easy and inexpensive screening of certain genetic risk markers for type 1 diabetes. The method should be applicable to using whole blood dried on sample collection cards as sample material, since the shipping and storage of samples in this format is preferred. However, the screening of vast sample libraries of extracted genomic DNA should also be possible, if such a need should arise, for example, when studying the effect of newly discovered genetic risk markers. The method developed in this study is based on homogeneous assay chemistry and an asymmetrical polymerase chain reaction (PCR). The generated singlestranded PCR product is probed by lanthanide-labelled, LNA (locked nucleic acid)-spiked, short oligonucleotides with exact complementary sequences. In the case of a perfect match, the probe is hybridised to the product. However, if even a single nucleotide difference occurs, the probe is bound instead of the PCR product to a complementary quencher-oligonucleotide labelled with a dabcyl-moiety, causing the signal of the lanthanide label to be quenched. The method was applied to the screening of the well-known type 1 diabetes risk alleles of the HLA-DQB1 gene. The method was shown to be suitable as an initial screening step including thousands of samples in the scheme used in the TEDDY (The Environmental Determinants of Diabetes in the Young) study to identify those individuals at increased genetic risk. The method was further developed into dry-reagent form to allow an even simpler approach to screening. The reagents needed in the assay were in dry format in the reaction vessel, and performing the assay required only the addition of the sample and, if necessary, water to rehydrate the reagents. This allows the assay to be successfully executed even by a person with minimal laboratory experience.

Avaliação da porosidade de microcápsulas contendo proteína bioativa por porosimetria de mercúrio e adsorção de nitrogênio

Microcapsules containing lactoferrin were produced by spray drying using dextrin:octenylsuccinate starch, as wall materials. Porosity characteristics of spray-dried microcapsules were investigated by mercury intrusion porosimetry and nitrogen adsorption. The outer and inner structures of microcapsules were studied by Scanning Electron Microscopy and sizes were determined by Laser Diffraction. Results indicate that all microcapsules presents adsorption isotherm of type II and that micropores on the microcapsules surface will be very few or none. Our results show that microstructure, surface area and size of microcapsules are affected by dextrin: octenylsuccinate starch proportion. Pore characteristics for various microcapsules are found to be different.

A validated method using RP-HPLC for quantification of reserpine in the Brazilian tree Rauvolfia sellowii Müll. Arg. (Apocynaceae)

This study describes a simple, fast and reproducible method using RP-HPLC-UV, in a gradient system, for quantification of reserpine in Rauvolfia sellowii stem bark. The analysis were carried out on a C18 column; mobile phase was water and acetonitrile, and separations were carried out in 10 min, flow rate of 1.0 mL min-1, 25 ºC and 268 nm. The validation data showed that the method was specific, accurate, precise and robust. Results were linear over a range of 0.625-40.0 μg mL-1, and the mean recovery was 95.1%. The amount of reserpine found in the dried stem bark was 0.01% (m/m).

Influência da secagem sobre o rendimento e composição química dos compostos voláteis das raízes de Piper piscatorum Trel. & Yunck. (Piperaceae)

In this study, we evaluated the yield and chemical composition of volatile compounds obtained from fresh, dried at 30 and 40 ºC respectively of Piper piscatorum, employing the technique of hydrodistillation. The volatile were chemically characterized by GC-MS and GC-FID. The main volatile compounds were selin-11-en-4-a-ol (57,63 ± 3,07%; 53,95 ± 1,56% and 56,20 ± 0,43%) and benzyl benzoate (15,40 ± 0,36%; 16,32 ± 0,85% and 15,04 ± 0,24%).The drying of the raw material reduced yield of volatile compounds, changing their chemical compositions.

Preparation of association compound between rhodium(II) citrate and β-cyclodextrin

Inclusion compound of rhodium(II) citrate with β-cyclodextrin in a 1:1 molar ratio was prepared using freeze-drying method. X-ray diffactometry, thermal analysis (TG/DTG/DSC), infrared and ¹H-NMR with ¹H spin lattice relaxation (¹H T1) measurements and 13C techniques were used to characterize the system prepared. The results indicated the formation of inclusion or association compounds between rhodium(II) citrate and β-cyclodextrin.

Isolation and quantitative HPLC-PDA analysis of lupeol in phytopharmaceutical intermediate products from Vernonanthura ferruginea (Less.) H. Rob.

Prior to obtain a standardized dried extract from V. ferruginea, lupeol was first time isolated from leaves and used as chemical maker. An analytical method using HPLC-PDA for lupeol determination in V. ferruginea intermediate products was developed using a C8 reverse-phase column, acetonitrile-acetic acid (99.99:0.01, v/v) as mobile phase at 0.8 mL min-1, oven temperature at 23-25 ºC, sample injection volume at 30 µL and detection at 210 nm. The method presented linearity from 10 to 160 µg mL-1, accuracy, precision, robustness and suitable sensitivity proving to be a useful tool to the obtainment process of lupeol standardized dried extracts of V. ferruginea.

Síntese de nanomateriais de carbono a partir do resíduo de milho (DDGS)

The world's largest ethanol producer (USA) uses corn as feedstock. DDGS (distillers dried grains with solubles) is the main waste generated from this process (around 32 million t/year). DDGS samples were pyrolyzed at 1000 ºC in a furnace with controlled atmosphere. The effluent was channeled to a second furnace, in which catalyst substrates were placed. Chromatographic analysis was used to evaluate the gaseous effluents, showing that the catalyst reduced hydrocarbon emissions. The solid products formed were analyzed by SEM and TEM. Graphitic structures and carbon nanofibers, 50 µm in length and with diameters of 80-200 nm, were formed.