Spray-dried solid dispersions containing ferulic acid: comparative analysis of three carriers,in vitro dissolution,antioxidant potential and in vivo anti-platelet effect

This article aimed to improve the relative solubility and dissolution rate of ferulic acid (FA) by the use of spray-dried solid dispersions (SDs) in order to ensure its in vitro antioxidant potential and to enhance its in vivo anti-platelet effect. These SDs were prepared by spray-drying at 10 and 20% of drug concentration using polyvinylpyrrolidone K30 (PVP-K30), polyethylene glycol 6000 (PEG 6000) and poloxamer-188 (PLX-188) as carriers. SDs and physical mixtures (PM) were characterized by SEM, XRPD, FTIR spectroscopy and TGA analysis. Spray-dried SDs containing FA were successfully obtained. Relative solubility of FA was improved with increasing carrier concentration. PVP-K30 and PEG 6000 formulations showed suitable drug content values close to 100%, whereas PLX-188 presented mean values between 70 and 90%. Agglomerates were observed depending on the carrier used. XRPD patterns and thermograms indicated that spray-drying led to drug amorphization and provided appropriate thermal stability, respectively. FTIR spectra demonstrated no remarkable interaction between carrier and drug for PEG 6000 and PLX-188 SDs. PVP-K30 formulations had changes in FTIR spectra, which denoted intermolecular O–H???O?=?C bonds. Spray-dried SDs played an important role in enhancing dissolution rate of FA when compared to pure drug. The free radical-scavenging assay confirmed that the antioxidant activity of PEG 6000 10% SDs was kept. This formulation also provided a statistically increased in vivo anti-platelet effect compared to pure drug. In summary, these formulations enhanced relative solubility and dissolution rate of FA and chosen formulation demonstrated suitable in vitro antioxidant activity and improved in vivo anti-platelet effect.     

Probing electric characteristics and sorting out metallic from semiconducting carbon nanotubes

Differences of the electric response of metallic and semiconducting single-walled carbon nanotubes (SWCNTs) to a DC electric field applied by the tip of a scanning probe microscope are reported. We show that conventional Electric Force Microscopy (EFM) images can be used to directly distinguish metallic from semiconducting SWCNTs on a process-free sample. Not only the magnitudes of their response are different, but, more important, the EFM line profile across a nanotube - its electric signature - is qualitatively distinct for metallic or semiconducting SWCNTs. The influence of nanotube length and diameter on their response to the applied field is also analyzed and shows remarkable differences. Theoretical modeling explains and fits the experimental data, giving support to this very simple, yet extremely accurate and all-encompassing methodology.     

Effects of slope exposure,altitude and yield on coffee quality in two altitude terroirs of Costa Rica,Orosi and Santa María de Dota

This study assessed the effects of slope exposure, altitude and yield on several cup quality criteria of coffees from two altitude terroirs of Costa Rica, Orosi (between 1020 and 1250 m above sea level) and Santa María de Dota (between 1550 and 1780 m above sea level). East‐facing slopes gave beverages with generally superior attributes, probably owing to better exposure to morning sunlight. These beverages were mainly more acid: at Orosi an acidity score of 2.73 out of 5 was obtained (3.64 for Santa María de Dota) for eastern exposures, as opposed to 2.36 on average (3.28 for Santa María de Dota) for other exposures. In addition, a positive relation was found between altitude and taster preferences in both terroirs. A negative relation was also found between yield and beverage acidity at Santa María de Dota, where some coffee trees produced up to 13 kg of coffee cherry. Coffees from Orosi were characterised by a floral flavour, which depended on slope exposure, whilst coffees from Santa María de Dota displayed a chocolate taste, which was more marked at high altitude. In both terroirs the caffeine, trigonelline, fat, sucrose and chlorogenic acid contents were not well correlated with the sensory characteristics. Copyright © 2005 Society of Chemical Industry     

Fatigue and subcritical crack growth in ZrO2–bioglass ceramics

This work investigates the characteristics of ZrO₂ based ceramics (Y-TZP) doped with bioglass developed for dental prostheses. Powder mixtures composed of zirconia and 3 or 5 wt% of 3CaO·P₂O₅–SiO₂–MgO bioglass were sintered at 1300 °C for 2 h. The samples were characterized by their phase composition using X-Ray diffraction (XRD) and analysis of their microstructure by scanning electronic microscopy (SEM). Hardness and fracture toughness were evaluated using the Vickers indentation method, while bending strength and fatigue resistance were determined using the four-point bending testing. The mechanical properties indicate that the samples achieved high density under the applied sinter conditions. X-ray diffraction analysis revealed tetragonal ZrO₂ as a major crystalline phase. Hardness, fracture toughness and bending strength of the sintered samples containing 3% or 5% bioglass were 1167and 1134 HV, 6.3 and 6.1 MPa m^1/2 and 453 and 636 MPa, respectively. The fatigue results presented large scattering, which is attributed to a heterogeneous distribution of the secondary glassy phase in the zirconia matrix. The non-uniform dispersion of the glass may result in the formation of stress gradients, possibly responsible for crack initiation and their respective subcritical growth during fatigue testing. The fatigue limit determined was superior to stresses developed during mastication, turning its use in dental prostheses viable. Weibull statistics were applied on the fatigue results obtained at average stress levels of 255, 270 and 285 MPa in order to calculate the subcritical crack growth. A life expectancy of over 20 years under severe cyclic pressure conditions has been calculated.     

Clinical comparison of cellulose and expanded polytetrafluoroethylene membranes in the treatment of class II furcations in mandibular molars with 6-month re-entry

To evaluate the clinical significance of serum levels of hepatocyte growth factor (HGF) in colorectal cancer patients, we measured the venous and portal concentrations of HGF in 60 patients. The tissue concentrations in the tumour and adjacent normal mucosa were also determined. The serum HGF concentration for the peripheral venous blood of the patients was significantly higher than that in normal controls. The content of HGF in cancer tissue was also significantly higher than that in normal mucosa, and it was correlated with the serum HGF concentration for the peripheral venous blood. The serum concentration of HGF reflected pathological features, including tumour size and lymph node or liver metastasis, and it showed an association with various preoperative nutritional parameters and the preoperative haemoglobin level. The serum HGF concentration was also correlated with the serum concentrations of immunosuppressive acidic protein and interleukin-6, indices of the host's immunological condition. Serum HGF seems to be a useful index of the disease status of patients with colorectal carcinoma.     

Influence des gaines sur la résistance des âmes de poutres en béton précontraint

Résumé Les recommandations du CEB-1978 préconisent, dans le cas de la vérification de la résistance des ames des poutres en béton précontraint à l'effort tranchant, la prise en compte de l'épaisseur effective de l'ame, déduite de la moitié de la somme des diamètres des gaines. Dans le but de vérifier cette recommandation, on a essayé jusqu'à la rupture par écrasement des bielles, 14 poutres en béton armé dont les seuls paramètres variables étaient les diamètres et l'injection ou non des gaines.

---

Summary CEB Recommendations preconize that in case of verification of the web strength of the prestressed concrete beams against the shear force, the effective web thickness (by deduction of the half sum of the ducts diameters) might be taken into account in the considered region b_wef=b_w−(1/2). Σ ?). With the purpose of verifying this recommendation, fourteen reinforced concrete beams were tested until the crushing of the concrete web, in the direction of the diagonal cracks. The beams had the same geometrical characteristics and the same transversal and longitudinal reinforcement. The variable parameters were the diameters of the ducts and their injection, or not, with mortar. We have concluded that in case the injection is reliable, a reduction of the value of the web thickness would not be necessary, and that in cases in which the full efficiency of the injection cannot be trusted, the reduction b_wef=b_w−0,38. Σ ? is recommended.

---

---

Recherche réalisée au Laboratoire de Structures du Centre de Technologie de l'Université Fédérale de Rio-de-Janeiro, comme thèse de Magister Scientiae (Ma?tre ès Sciences) du premier auteur, E. M. R. Fairbairn, présentée à la COPPE (Centre de Post-Graduation de l'UFRJ) [8].     

Combined effects of lactic acid and nisin solution in reducing levels of microbiological contamination in red meat carcasses

Changes in bacterial counts on beef carcasses at specific points during slaughter and fabrication were determined, and the effectiveness of nisin, lactic acid, and a combination of the lactic acid and nisin in reducing levels of microbiological contamination was assessed. Swab samples were obtained from the surfaces of randomly selected beef carcasses. Carcasses were swabbed from the neck, brisket, and renal site after skinning, splitting, and washing. Treatments involving lactic acid (1.5%), nisin (500 IU/ml), or a mixture of nisin and lactic acid were applied after the neck area was washed. A control group was not sprayed. Results indicated that the highest prevalence of aerobic plate counts (APCs), total coliforms, and Escherichia coli was found in the neck site after splitting, and the lowest level of microbial contamination was found after skinning. Washing with water did not significantly reduce the bacterial load. The largest reduction in APCs, total coliforms, and E. coli occurred on carcasses treated with a mixture of nisin and lactic acid. A mixture of nisin and lactic acid can be applied to beef carcasses through spray washing and can reduce bacterial populations by 2 log units.     

Cover Image

The cover image is based on the Review Review: materials and modelling for organic photovoltaic devices by Olivier Doat et al., https://doi.org/10.1002/pi.6280 .