Chemical composition of rainwater at a coastal town on the southwest of Europe: what changes in 20 years?

Rainwater was collected at the Portuguese west coast between September 2008 and September 2009, and analysed for pH, conductivity, and Cl⁻, NO₃⁻, SO₄²⁻, and NH₄⁺ concentrations. Results of rainwater chemical composition were compared with those obtained at the same site between 1986 and 1989. In both collection periods rainwater was predominantly (≈ 80%) associated to oceanic air masses. The rainwater concentration of H⁺ was in the same range as twenty years ago. A clear decrease of non sea salt sulphate (NSS-SO₄²⁻) was observed in 2008-2009 relatively to 1986-1989, not only in samples with origin in central and northern Europe, but also in samples from Atlantic Ocean and Mediterranean. This decrease indicates that SO₂ emissions were reduced, which may be due to a lower content of sulphur in oil by-products. A decrease was also observed in NH₄⁺ concentration in 2008-2009. On the contrary an increase of NO₃⁻ concentration was observed for samples of all origins in 2008-2009 relatively to 1986-1989, which was particularly high (more than 3 fold) for samples with origin in Atlantic Ocean, suggesting the incorporation of this ion by rainout at the sampling site. The contribution of local sources is indeed suggested by the moderate negative correlation of NH₄⁺, NO₃⁻ and NSS-SO₄²⁻ with rainwater volume. The high increase of NO₃⁻ concentration can be attributed to the increase of local vehicular and industrial emissions in the sampling area.     

The Structure and Bond Strength of Composite Carbide Coatings (WC-Co + Ni) Deposited on Ductile Cast Iron by Thermal Spraying

An investigation was conducted to determine the role of Ni particles in the WC-Co coating produced with the supersonic method on microstructure, mechanical, and wear properties in a system of type: WC-Co coating/ductile cast iron. The microstructure of the thermal-sprayed WC-Co + Ni coating was characterized by scanning electron and transmission electron microscopes as well as the analysis of chemical and phase composition in microareas (EDS, XRD). The microstructure of the WC-Co + Ni coating consisted of large, partially molten Ni particles and very fine grains of WC embedded in cobalt matrix, coming to the size of nanocrystalline. Moreover, the results were discussed in reference to examination of bending strength considering cracking and delamination in the system of (WC-Co + Ni)/ductile cast iron as well as hardness and wear resistance of the coating. It was found that the addition of Ni particles was significantly increase resistance to cracking and wear behavior in the studied system.     

The Potential of Plant Phenolics in Prevention and Therapy of Skin Disorders

Phenolic compounds constitute a group of secondary metabolites which have important functions in plants. Besides the beneficial effects on the plant host, phenolic metabolites (polyphenols) exhibit a series of biological properties that influence the human in a health-promoting manner. Evidence suggests that people can benefit from plant phenolics obtained either by the diet or through skin application, because they can alleviate symptoms and inhibit the development of various skin disorders. Due to their natural origin and low toxicity, phenolic compounds are a promising tool in eliminating the causes and effects of skin aging, skin diseases, and skin damage, including wounds and burns. Polyphenols also act protectively and help prevent or attenuate the progression of certain skin disorders, both embarrassing minor problems (e.g., wrinkles, acne) or serious, potentially life-threatening diseases such as cancer. This paper reviews the latest reports on the potential therapy of skin disorders through treatment with phenolic compounds, considering mostly a single specific compound or a combination of compounds in a plant extract.     

Protection of Historical Wood against Microbial Degradation—Selection and Application of Microbiocides

The aim of this study was to select effective and safe microbiocides for the disinfection and protection of historical wooden surfaces at the former Auschwitz II-Birkenau concentration and extermination camp. We tested seven active compounds against bacteria and moulds, of which didecyldimethylammonium chloride and N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine were effective even at 0.02%–2%. Subsequently, eight microbiocides containing the selected active ingredients were chosen and applied three times on the surface of wood samples colonized by bacteria and moulds. ABM-1 and ABM-2—6% solution; Rocima 101—8%; Preventol R 80—12%; Acticide 706 LV—15% and Boramon—30% were the most effective disinfectants. Under laboratory conditions, ABM-1, Boramon and Rocima 101 ensured antimicrobial protection of new wood samples for six months. In situ, 30% Boramon and 8% Rocima 101 applied by spraying effectively protected the historical wood from bacterial and mould growth for 12 and 3 months, respectively. Colour and luminance of the new wood were not altered after exposure to the biocides. Boramon and Rocima 101, applied by the spraying method, caused no significant change in the colour of the historical wood. Results from this study were used to develop a procedure for the protection of wood in historical buildings against biodeterioration.     

Bifunctional Metal Organic Framework Catalysts for Multistep Reactions: MOF‐Cu(BTC)‐[Pd] Catalyst for One‐Pot Heteroannulation of Acetylenic Compounds

A bifunctional metal organic framework catalyst containing palladium and copper(II) benzene‐1,3,5‐tricarboxylate – MOF‐Cu(BTC)‐[Pd] – has been prepared. This catalyst enables the performance of the tandem Sonogashira/click reaction starting from 2‐iodobenzylbromide, sodium azide and alkynes to produce 8H‐[1,2,3]triazolo[5,1‐a]isoindoles with good yields under mild reaction conditions.     

Light-harvesting bio-nanomaterial using porous silicon and photosynthetic reaction center

ABSTRACT: Porous silicon microcavity (PSiMc) structures were used to immobilize the photosynthetic reaction center (RC) purified from the purple bacterium Rhodobacter sphaeroides R-26. Two different binding methods were compared by specular reflectance measurements. Structural characterization of PSiMc was performed by scanning electron microscopy and atomic force microscopy. The activity of the immobilized RC was checked by measuring the visible absorption spectra of the externally added electron donor, mammalian cytochrome c. PSi/RC complex was found to oxidize the cytochrome c after every saturating Xe flash, indicating the accessibility of specific surface binding sites on the immobilized RC, for the external electron donor. This new type of bio-nanomaterial is considered as an excellent model for new generation applications of silicon-based electronics and biological redox systems.     

Synthesis of hexyl butyrate (apple and citrus aroma) by Candida rugosa lipase immobilized on Diaion HP-20 using the Box-Behnken design

Food Science and Biotechnology - This study aims at the synthesis of hexyl butyrate by Candida rugosa lipase (CRL) immobilized on Diaion HP 20. The lipase load used was...     

Immunophenotypic,immunocytochemistry, ultrastructural,and cytogenetic characterization of mesenchymal stem cells from equine bone marrow

The aim of this study was to isolate, culture, and characterize mesenchymal stem cells (MSCs) from horse bone marrow (BM) using the techniques of flow cytometry, immunocytochemistry, cytogenetics, and electron microscopy. Immunophenotypic analysis revealed the presence of MSCs with high expression of the CD90 marker, lower expression of the CD44 marker, and absent expression of the CD34 marker. In assays of differentiation, the positive response to osteogenic (OST), chondrogenic (CDG), and adipogenic (ADP) differentiation signals was observed and characterized by deposition of calcium‐rich extracellular matrix (OST), proteoglycans and collagen II (CDG) and intracellular deposition of fat drops (ADP). In immunocytochemical characterization, MSCs were immunopositive for CD44, vimentin, and PCNA, and they were negative for CD13. In the ultrastructural analysis of MSCs, the most outstanding characteristic was the presence of rough endoplasmic reticulum with very dilated cisterns filled with a low electrodensity material. Additionally, MSCs had normal karyotypes (2n = 64) as evidenced by cytogenetic analysis, and aneuploidy in metaphase was not observed. The protocols for isolating, culturing, and characterizing equine MSCs used in this study were shown to be appropriate for the production of a cell population with a good potential for differentiation and without aneuploidy that can be used to study future cellular therapies. Microsc. Res. Tech. 76:618–624, 2013. © 2013 Wiley Periodicals, Inc.     

Determining the effective diffusion coefficient of water in banana (Prata variety) during osmotic dehydration and its use in predictive models

The objective of this study was to develop a suitable method for determining the effective diffusion coefficient of water in banana (Prata variety) from experimental data of osmotic dehydration (OD) and using this coefficient for predicting dehydration of the same sample under other situations. Different methods were compared in order to determine the best coefficient to be used in the predictive models. The analytical solution of the diffusion equation allowed estimating averaged values of coefficients between the initial moisture and the average sample moisture at a given instant. The numerical method allowed estimating how the effective diffusion coefficient varies with the moisture. The models prediction ability were validated using a dehydration data set not used for estimating the diffusion coefficients. The use of the diffusive model with a coefficient that depends on the moisture content has the best predictive ability, because it takes into account that the coefficient decreases during the OD.     

Influence of sodium dodecyl sulfate and cetyl trimethylammonium bromide upon calcium carbonate precipitation on bacterial cellulose

Calcium carbonate was deposed on bacterial cellulose (BC) never-dried membranes in the presence of different concentrations of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB) by a precipitation reaction between aqueous solutions of calcium chloride (CaCl₂) and sodium carbonate (Na₂CO₃) containing, or not, surfactant in their composition. Different shapes of crystals were obtained from rhombohedral ones to flowerlike, depending on surfactant type and concentration. From the two surfactants tested, SDS has a greater influence on calcium carbonate morphology than CTAB. The only polymorph obtained in all studied cases was calcite. The composite films BC-calcite were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and color measurements. The obtained BC-calcium carbonate composites could be used in paper manufacturing.