Growth promotion and elicitor activity of salicylic acid in Achillea millefolium L.

Salicylic acid (SA) is a phenolic compound present in plants and has multiple functions, including hormonal effect on stimulus of plant growth and development and induction of plant defense responses under conditions of biotic and abiotic stresses. Studies related to SA’s elicitor action on the synthesis of secondary metabolite in medicinal plants have been conducted in order to increase the economic value of these species. The objective of this study was to determine the effect of SA foliar application on biomass production and the synthesis of secondary compounds in yarrow (Achillea millefolium L. - Asteraceae). The experiment was conducted in potted plants under greenhouse conditions. The SA application was done at concentrations of 0, 0.25, 0.50 and 1.00 mM 20 days after transplanting the seedlings to pots. The effect of SA on the metabolism of yarrow plants was evaluated through biometric parameters of growth and biochemical parameters. The SA at 0.50 mM resulted in linear increases in biomass accumulation of roots, total dry mass, ratio root/shoot and chlorophyll a and chlorophyll a+b content in yarrow plants.The application of SA at 0.50 and 1.00 mM was most effective in eliciting the production of essential oils and total phenols, with a consequent improvement of the antioxidant activity of the plant extract. It can be concluded that SA application constitutes an advantageous management practice for commercial production of Achillea millefolium, increasing the nutraceutical and medicinal values of this species.Key words: Photosynthetic pigments, essential oil, phenolic compounds, antioxidant activity

Cathepsin L of Triatoma brasiliensis (Reduviidae, Triatominae): Sequence characterization, expression pattern and zymography

AbstractTriatoma brasiliensis is considered one of the main vectors of Chagas disease commonly found in semi-arid areas of northeastern Brazil. These insects use proteases, such as carboxypeptidase B, aminopeptidases and different cathepsins for blood digestion. In the present study, two genes encoding cathepsin L from the midgut of T. brasiliensis were identified and characterized. Mature T. brasiliensis cathepsin L-like proteinases (TBCATL-1, TBCATL-2) showed a high level of identity to the cathepsin L-like proteinases of other insects, with highest similarity to Rhodnius prolixus. Both cathepsin L transcripts were highly abundant in the posterior midgut region, the main region of the blood digestion. Determination of the pH in the whole intestine of unfed T. brasiliensis revealed alkaline conditions in the anterior midgut region (stomach) and acidic conditions in the posterior midgut region (small intestine). Gelatine in-gel zymography showed the activity of at least four distinct proteinases in the small intestine and the cysteine proteinase inhibitors transepoxysuccinyl-l-leucylamido-(4-guanidino)butane (E-64) and cathepsin B inhibitor and N-(l-3-trans-propylcarbamoyl-oxirane-2-carbonyl)-l-isoleucyl-l-proline (CA-074) were employed to characterize enzymatic activity. E-64 fully inhibited cysteine proteinase activity, whereas in the samples treated with CA-074 residual proteinase activity was detectable. Thus, proteolytic activity could at least partially be ascribed to cathepsin L. Western blot analysis using specific anti cathepsin L antibodies confirmed the presence of cathepsin L in the lumen of the small intestine of the insects

Biomass allometry and carbon factors for a Mediterranean pine (Pinus pinea L.) in Portugal

Forests play an important role in the global carbon balance because they offset a large portion of the carbon dioxide emitted through human activities. Accurate estimates are necessary for national reporting of greenhouse gas inventories, carbon credit trading and forest carbon management but in Portugal reliable and accessible forest carbon measurement methodologies are still lacking for some species. The objective of this study was to provide forest managers with a comprehensive database of carbon factors and equations that allows estimating stand-level carbon stocks in Pinus pinea L. (P. pinea), regardless of the tree inventory information available. We produced aboveground biomass and stem volume equations, biomass expansion factors (BEF) by component as well as wood basic density (WBD) and component carbon fraction in biomass. A root-to-shoot ratio is also presented using data from trees in which the root system was completely excavated. We harvested 53 trees in centre and south Portugal covering different sizes (6.5 to 56.3 cm), ages (10 to 45 years) and stand densities (20 to 580 trees ha–1). The results indicate that aboveground allometry in P. pinea is not comparable with other pines and varies considerably with stand characteristics, highlighting the need to develop stand-dependent factors and equations for local or regional carbon calculations. BEFaboveground decreases from open (1.33 ± 0.03 Mg m–3) to closed stands (1.07 ± 0.01 Mg m–3) due to a change in biomass allocation pattern from stem to branches. Average WBD was 0.50 ± 0.01 Mg m–3 but varies with tree dimensions and the root-to-shoot ratio found was 0.30 ± 0.03. The carbon fraction was statistically different from the commonly used 0.5 factor for some biomass components. The equations and factors produced allow evaluating carbon stocks in P. pinea stands in Portugal, contributing to a more accurate estimation of carbon sequestered by this forest type

Environmental and energy performance of residual forest biomass for electricity generation: gasification vs. combustion

Bioenergy systems have a great potential worldwide to substitute fossil fuels mainly because they may contribute to greenhouse gas emissions reduction. In Portugal, several biomass combustion-based power plants have been built in the last decade. Biomass gasification is a potential alternative to combustion but its environmental impacts should be evaluated. The goal of this study is to assess and compare the environmental and energy performance of direct gasification and combustion (both in fluidized bed) using residual forest biomass (RFB) from eucalypt in Portugal. In order to achieve the goal, life cycle assessment was applied, complemented with the Energy-Returned-On-Energy-Invested (EROI) indicator. The boundaries of the systems comprise three stages: (1) forest management, (2) collection, processing and transportation, and (3) electricity generation. The results indicate that gasification performs environmentally better than combustion in 5 out of 8 impact categories addressed. Conversely, combustion has greater EROI than gasification. After running a sensitivity analysis where the efficiency of the gasifier was changed from 53% in the base scenario to 57%, it is shown that the environmental performance of gasification improved in the range of 2–8%. The study concludes that gasification may be a good alternative to current combustion systems in Portugal.publishe

Facile synthesis and characterization of MnxZn1-xFe2O4/activated carbon composites for biomedical applications

"The synthesis of MnxZn1-xFe2O4 ferrites (x = 0.4, 0.5 and 0.6) by means of the co-precipitation method is reported. Furthermore, a composite of Mn0.4Zn0.6Fe2O4/activated carbon was prepared with the mechanosynthesis method. The magnetic, structural, morphological and chemical properties were analyzed by means of VSM, XRD, SEM, FTIR and Boehm's titration. The heating capacity was evaluated under a magnetic field using solid-state induction heating equipment, in addition a hemolysis test was performed using human red blood cells. With regard to the synthesis of manganese-zinc ferrite, the results indicated that Mn0.4Zn0.6Fe2O4 ferrite showed higher saturation magnetization (64.48 emu/g) than the other ferrite obtained, with superparamagnetic behavior. The Mn0.4Zn0.6Fe2O4/activated carbon composite was able to heat in concentrations of 10 mg/ml under a magnetic field (10.2 kAm-1 and frequency 200 kHz), increasing the temperature up to 42.5 °C. The hemolysis test indicated that the presence of activated carbon reduces the hemolytic behavior of the ferrite. Thanks to its heating capacity and non-hemolytic activity, theMn0.4Zn0.6Fe2O4/activated carbon composite is a potential candidate for use in biomedical applications.

On-line polymerisation monitoring in scCO2: a reliable and inexpensive sampling method in high pressure applications

A versatile and reliable on-line sampling system for polymerisation reactions in supercritical fluids was developed. By withdrawing a small volume of a high-pressure reaction mixture and expanding it in a controlled volume, reliable kinetic data were obtained for a range of reactions in scCO2, avoiding the need for costly equipment or setup modifications. All experiments were carried out in a stainless-steel high-pressure autoclave with mechanical stirring and a volume of 60 ml. With the polymerisation of methyl methacrylate (MMA) in scCO2 being widely adopted for research in the past, the free-radical and RAFT controlled dispersion polymerisations of MMA were analysed in detail using the sampling system as a proof-of-concept. Additionally, initial implementation of the sampling system to a range of different reactions showed the facile applicability of the monitoring method