Substitution of urea-formaldehyde by renewable phenolic compound for environmentally appropriate production of particleboards.

In recent years, research has been conducted in search of alternative adhesives that are less harmful to human health and the environment. Cardanol derived from cashew nut shell liquid (CNSL) has attracted considerable attention due to its chemical and specific characteristics (antioxidant activity, flame resistance, and hydrophobicity). In this sense, this study aimed to evaluate the quality of particleboards using cardanol instead of urea-formaldehyde (UF) adhesive. Different percentages of cardanol were used (0, 20, 40, 60 and 80%) in which its physicochemical properties were evaluated. The panels were produced with particles of Pinus oocarpa and nominal density of 0.75 g/cm3, their physical and mechanical properties were evaluated, wood-adhesive interface evaluation with scanning electron microscopy (SEM), and the combustibility test. It is concluded that the maximum replacement of UF by cardanol is 5%, since, in this situation, the mentioned properties reach the established norms for the commercialization of the boards.

Interaction with Modified Cyclodextrin as a Way to Increase the Antimalarial Activity of Primaquine.

BACKGROUND: Malaria is still a dangerous disease that impacts specifically Africa, Asia, and Latin America. The development of therapies to overcome the parasite infection is an important challenge nowadays. The medicine primaquine (PQ) is used in the treatment, although several side effects and low oral bioavailability are reported. OBJECTIVE: This work focused on the preparation and characterization of a complex between PQ and 2- hydroxypropyl-ß-cyclodextrin (HPCD), besides performing release tests of this formulation. METHODS: PQ:HPCD complexes were prepared at 1:1 and 1:2 molar ratios, by the lyophilization method. The association between PQ and HPCD was tested using UV-vis, infrared (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy and NMR techniques (chemical shift, Job Plot, DOSY, and ROESY). Tests were also conducted to evaluate drug release before and after complexation with HPCD. RESULTS: Results showed that there was a weak interaction of PQ with HPCD, forming non-inclusion complexes. These results were supported by FTIR results and spatial correlations between hydrogens from PQ with the external HPCD hydrogens. A 1:2 PQ:HPCD preferred molar ratio was determined by DSC and Job Plot experiments and the time to release 96% of the drug was 21.2 h slower after complexation. CONCLUSION: Conclusion indicate that PQ interacts poorly with HPCD, probably due to its hydrophilic character, as well as to its interaction with the external rim of HPCD. Our results demonstrate that there was a significant improvement in the release time after the complexation process, which could lead to an increase in the activity of the drug.

El humor vítreo como fluido biológico de importancia clínica en ciencias forenses / Vitreous humour as a biofluid of clinical importance in forensic sciences / Humor vítreo como fluido biológico de importância clínica nas ciências forenses

El humor, cuerpo o fluido vítreo (HV) es un gel claro que ocupa la cavidad vítrea o cavidad posterior del globo ocular y cuyas funciones son las de dar volumen al ojo, sostener la retina y mantener su transparencia de manera que los haces de luz puedan atravesarla. En este estudio se aborda la importancia del humor vítreo como muestra en el área de la bioquímica clínica, y se destaca su valor en el ámbito de las ciencias forenses. El humor vítreo es una muestra indispensable en la investigación de casos de muertes sospechosas, inexplicables o violentas, puesto que su ubicación proporciona un medio estéril para determinaciones como la confirmación post mortem de la ingestión de etanol. Tiene un rol en la determinación de drogas, intervalo post mortem, diabetes, deshidratación, desnutrición e insuficiencia renal. La interpretación de los datos puede ser problemática donde factores como la difusión post mortem de las drogas desde el cerebro hacia la cavidad vítrea, el método analítico, la recolección de la muestra, la calibración y el tratamiento estadístico de los datos aportan dificultad en la interpretación y añaden más variables a la hipótesis de investigación. La investigación del humor vítreo como matriz de análisis tiene una importancia considerable y debería ser difundida en países como Brasil y otros de América Latina donde, a pesar de existir personal capacitado para trabajar con esta muestra, este tipo de análisis no se pone en práctica con la debida frecuencia.

The vitreous humor, body or fluid is the clear gel that fills the vitreous chamber or posterior chamber of the eyeball, whose functions are to give volume to the eye, serve as retina support and maintain its transparency to allow light beams to reach the retina. This study addresses the vitreous humor as an important sample for clinical biochemistry, pointing out its value for forensic sciences. The vitreous humor is a mandatory sample in cases of suspected, unexplained or violent deaths and its location gives a sterile medium for the postmortem confirmation of alcohol intake. It plays a role in the measurement of drugs, estimation of postmortem interval, and definition of diabetes, dehydration and renal failure. Factors such as drug postmortem diffusion in the vitreous humour coming from the brain, along with factors of the analytical method such asthe collection process, calibration and statistical processing of data, make it difficult to interpret and add more variables to the cases investigated. HV use should be promoted in countries like Brazil and in Latin America, which possess trained professionals to address and use this biological sample, but who do not work with it frequently.

O humor, corpo ou fluido vítreo (HV) é um gel claro que enche a cavidade vítrea ou cavidade posterior do globo ocular, cujas funções são dar volume ao olho, apoiar a retina e manter a sua transparência para permitir que os feixes de luz possam atravessá-la. Este trabalho aborda a importância do humor vítreo como amostra na área da bioquímica clínica, destacando seu valor no âmbito das ciências forenses. O humor vítreo é amostra obrigatória na investigação de casos de mortes suspeitas, inexplicáveis ou violentas, visto que sua localização provê um meio estéril para, por exemplo, determinações como a confirmação post mortem da ingestão de etanol. Tem um papel na mensuração de drogas, estimação do intervalo post mortem, diabetes, desidratação, desnutrição e insuficiência renal. Fatores como a difusão post mortem das drogas desde o cérebro para a cavidade vítrea, juntamente com o método analítico, o processo de coleta da amostra, calibração e tratamento estatístico dos dados, trazem dificuldades na interpretação e adicionam mais variáveis às hipóteses de investigação. A investigação do humor vítreo como matriz de análise tem importância considerável e deveria ser divulgada em países como o Brasil e outros da América Latina onde, apesar de contar com profissionais capacitados para trabalhar com esta amostra, ainda não colocam em prática esta análise com a merecida frequência.

Theoretical and experimental study of a praziquantel and beta-cyclodextrin inclusion complex using molecular mechanic calculations and H1-nuclear magnetic resonance.

Praziquantel (PZQ) is a broadly effective anthelminthic drug available for human and veterinary use, being the drug of choice for the treatment of all forms of schistosomiasis. Nevertheless, large doses are required in order to achieve adequate concentrations at the target site due to the poor solubility of PZQ and its significant first pass metabolism. To improve it, avoiding efficiency loss, we have designed a controlled-release system, in which PZQ was encapsulated in beta-cyclodextrin (beta-CD). The inclusion complexes between PZQ/beta-CD were studied at two different stoichiometries 1:1 and 1:2, through experimental and theoretical analysis. Molecular modeling calculations were used to foresee the better stoichiometry of the complex formed as well as the possible orientations of PZQ inside the beta-CD cavity. The complexes prepared were analyzed through H1 two-dimensional nuclear magnetic resonance (H1 2D-NMR) experiments, which provide (evidences) for the 1:1 complexation of PZQ/beta-CD. H1 2D-NMR also revealed details of PZQ/beta-CD molecular interaction, in which the isoquinoline ring of praziquantel is located inside the beta-CD cavity. Finally, phase-solubility diagrams revealed a five-fold increase in praziquantel water solubility upon addition of increasing beta-CD concentrations up to 16 mM, corresponding to the solubility of beta-CD itself. The solubilization profile is consistent with 1:1 stoichiometry of the PZQ/beta-CD complex while the solubilization effect will certainly increase the pharmacological activity of praziquantel.

Hydroxyzine, promethazine and thioridazine interaction with phospholipid monomolecular layers at the air-water interface.

In this work the interaction of Hydroxyzine, Promethazine and Thioridazine with Langmuir films of dipalmitoylphosphatidylcholine (dpPC) and dipalmitoylphosphatidic acid (dpPA), is studied. Temporal variations in lateral surface pressure (pi) were measured at different initial pi (pi(i)), subphase pH and drug-concentration. Drugs with the smallest (PRO) and largest (HYD) molecular size exhibited the lowest adsorption (k(a)) and the highest desorption (k(d)) rate constant values, respectively. The affinity binding constants (K(b)) obtained in monolayers followed the same profile (K(b,PRO) < K(b,HYD) < K(b,THI)) of the egg-PC/water partition coefficients (P) determined in bilayers. The drug concentration required to reach the half-maximal Deltapi at pi(i) = 14 mN/m (K(0.5)), was very sensitive to pH. The maximal increment in pi upon drug incorporation into the monolayer (deltapi(max)) will depend on the phospholipid collapse pressure (pi(c)), the monolayers's compressibility and drug's size, shape and charge. The higher pi(c) of dpPC lead to higher pi(cut-off) values (maximal pi allowing drug penetration), if compared with dpPA. In dpPC and dpPA pi(cut-off) decreased as a function of the molecular size of the uncharged drugs. In dpPA, protonated drugs became electrostatically trapped at the monolayer surface hence drug penetration, monolayer deformation and pi increase were impaired and the correlation between pi(cut-off) and drug molecular size was lost.