Liquid–Liquid Phase Equilibrium and Ion-Exchange Exploration for Aqueous Two-Phase Systems of ([C4mim]Cl + K2CO3 or K3C6H5O7 + water) at Different Temperatures

Journal of Solution Chemistry - Liquid–liquid equilibrium (LLE) data and phase diagrams for new aqueous two-phase systems (ATPSs) containing 1-butyl-3-methylimidazolium chloride...     

Preparation and characterization of microcapsules loaded with polyphenols-enriched Uncaria tomentosa extract using spray-dryer technique

Journal of Thermal Analysis and Calorimetry - This work prepared and characterized microcapsule of Uncaria tomentosa (UT) in order to standardize a spray-dryer Uncaria tomentosa extract. The UT...     

Antiprotozoal and Antibacterial Activity of Ravenelin,a Xanthone Isolated from the Endophytic Fungus Exserohilum rostratum

The natural compound ravenelin was isolated from the biomass extracts of Exserohilum rostratum fungus, and its antimicrobial, antiplasmodial, and trypanocidal activities were evaluated. Ravenelin was isolated by column chromatography and HPLC and identified by NMR and MS. The susceptibility of Gram-positive and Gram-negative bacteria strains to ravenelin was determined by microbroth dilution assay. Cytotoxicity was evaluated in hepatocarcinoma cells (HepG2) and BALB/c peritoneal macrophages by using MTT. SYBR Green I-based assay was used in the asexual stages of Plasmodium falciparum. Trypanocidal activity was tested against the epimastigote and intracellular amastigote forms of Trypanosoma cruzi. Ravenelin was active against Gram-positive bacteria strains, with emphasis on Bacillus subtilis (MIC value of 7.5 µM). Ravenelin’s antiparasitic activities were assessed against both the epimastigote (IC₅₀ value of 5 ± 1 µM) and the intracellular amastigote forms of T. cruzi (IC₅₀ value of 9 ± 2 µM), as well as against P. falciparum (IC₅₀ value of 3.4 ± 0.4 µM). Ravenelin showed low cytotoxic effects on both HepG2 (CC₅₀ > 50 µM) and peritoneal macrophage (CC₅₀ = 185 ± 1 µM) cells with attractive selectivity for the parasites (SI values > 15). These findings indicate that ravenelin is a natural compound with both antibacterial and antiparasitic activities, and considerable selectivity indexes. Therefore, ravenelin is an attractive candidate for hit-to-lead development.     

Lipid-Based Nanostructures for the Delivery of Natural Antimicrobials

Encapsulation can be a suitable strategy to protect natural antimicrobial substances against some harsh conditions of processing and storage and to provide efficient formulations for antimicrobial delivery. Lipid-based nanostructures, including liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid nanocarriers (NLCs), are valuable systems for the delivery and controlled release of natural antimicrobial substances. These nanostructures have been used as carriers for bacteriocins and other antimicrobial peptides, antimicrobial enzymes, essential oils, and antimicrobial phytochemicals. Most studies are conducted with liposomes, although the potential of SLNs and NLCs as antimicrobial nanocarriers is not yet fully established. Some studies reveal that lipid-based formulations can be used for co-encapsulation of natural antimicrobials, improving their potential to control microbial pathogens.     

Tablet of Spondias mombin L. Developed from Nebulized Extract Prevents Gastric Ulcers in Mice via Cytoprotective and Antisecretory Effects

Spondias mombin L. (Anacardiaceae) has a worldwide distribution and is present in all regions of Brazil. Its leaves, flowers and bark are used as teas in folk medicine to treat diseases of the digestive system. This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity, and the related mechanisms of action of nebulized extract and tablets based on dried Spondias mombin (SmNE). SmNE screening showed the presence of flavonoids (0.65%), polyphenols (25.50%), where the major compound is gallic acid. In the acute oral toxicity assay, a dose of 2000 mg/kg of SmNE administered orally in Swiss mice did not induce any behavioral changes. SmNE (250 or 500 mg/kg p.o) significantly reduced the ulcerative lesion area when compared to the control group in ethanol and non-steroidal anti-inflammatory drug (NSAIDs) models. Results showed that treatment with SmNE (250 mg/kg) reduced acid secretion and gastric content, accompanied with an increase in pH. Previous administration of indomethacin and glibenclamide reversed the protection provided by SmNE, confirming the participation of prostaglandins (PGs) and ATP-sensitive potassium channels (KATP) in its gastroprotective effect. The SmNE tablets met the pharmacopeial quality requirements with gastroprotective activity and similar protection in comparison to the isolated extract administrated. In conclusion, SmNe has a gastroprotective activity related to cytoprotective mechanisms, such as the participation of endogenous prostaglandins and KATP channels, having an anti-secretory effect with systemic action. The formulation obtained presented gastroprotective effects similar to the administration of the extract, the tablets showed favorable compression characteristics by the direct route and met the pharmacopeial quality requirements.     

Evaluating the freeze–thaw phenomenon in sandwich-structured composites via numerical simulations and infrared thermography

Journal of Thermal Analysis and Calorimetry - The water ingress phenomenon in sandwich-structured composites used in the aerospace/aeronautical sector is a current issue. This type of defect can...     

Noise robustness of the nonlocality of entangled quantum states

We study the nonlocal properties of states resulting from the mixture of an arbitrary entangled state rho of two d-dimensional systems and completely depolarized noise, with respective weights p and 1-p. We first construct a local model for the case in which rho is maximally entangled and p at or below a certain bound. We then extend the model to arbitrary rho. Our results provide bounds on the resistance to noise of the nonlocal correlations of entangled states. For projective measurements, the critical value of the noise parameter p for which the state becomes local is at least asymptotically log(d) larger than the critical value for separability.     

Aeolian transport of sand

The airborne transport of particles on a granular surface by the saltation mechanism is studied through numerical simulation of particles dragged by turbulent air flow. We calculate the saturated flux q_s and show that its dependence on the wind strength u_* is consistent with several empirical relations obtained from experimental measurements. We propose and explain a new relation for fluxes close to the threshold velocity u_t, namely, q_s=a(u_*-u_t)^α with α≈2. We also obtain the distortion of the velocity profile of the wind due to the drag of the particles and find a novel dynamical scaling relation. We also obtain a new expression for the dependence of the height of the saltation layer as function of the strength of the wind.     

Strategies of karyotype differentiation in Elateridae (Coleoptera, Polyphaga)

The chromosome study of five species of the family Elateridae, belonging to the subfamilies Agrypninae and Elaterinae, and the analysis of the cytogenetic data previously recorded for this family permitted the establishment of the main strategies of karyotypic differentiation that has occurred in the elaterids. In Agrypninae, the three species studied (Conoderus fuscofasciatus, Conoderus rufidens, and Conoderus sp.) showed the male karyotype 2n=16+X0. This karyotypic uniformity detected in these Conoderus species has also been shared with other species of the same genus, differing considerably from chromosomal heterogeneity verified in the subfamily Agrypninae. The use of the C-banding technique in C. fuscofasciatus and Conoderus sp. revealed constitutive heterochromatin in the pericentromeric region of the majority of the chromosomes. In C. fuscofasciatus, additional constitutive heterochromatin were also observed in the long arm terminal region of almost all chromosomes. Among the representatives of Elaterinae, the karyotype 2n=18+Xy(p) of Pomachilius sp.2 was similar to that verified in the majority of the Coleoptera species, contrasting with the chromosomal formula 2n=18+X0 detected in Cardiorhinus rufilateris, which is most common in the species of Elaterinae. In the majority of the elaterids, the chromosomal differentiation has frequently been driven by reduction of the diploid number; but, among the four cytogenetically examined subfamilies, there are some differences in relation to the trends of karyotypic evolution.     

Morphologic changes in the urethral epithelium in an ethanol-drinking rat strain (UChA and UChB)

The extreme use of ethanol causes metabolic and pathologic changes in testes and urogenital system in different animal species. The enzyme alcohol dehydrogenase (ADH) catalyses the conversion of ethanol into carcinogenic metabolite acetaldehyde which is partly excreted into the urine. However, papers relating the chronic ethanol consumption to the urethral morphology are unknown. This work evaluates the toxic effect of the chronic ethanol ingestion on the urethral epithelium of UChA and UChB rats. Conventional techniques of histology, histochemistry, immunohistochemistry and ultrastructural analysis were used. The analysis showed the presence of lipid drops and intercellular spaces in the epithelial cells in the urethra of UChA and UChB rats compared to control rats. Urethral neuroendocrine cell were observed and characterized for presenting vesicles containing electron-dense granules associated with nervous fibers. We conclude that the chronic consumption of ethanol induces the presence lipid drops in the epithelial cells of the urethra of UChA and UChB rats. The NE cells of the urethra of UChA and UChB rats did not show alterations under chronic effect of the ethanol.