SAFIIRA: A heavy-ion multi-purpose irradiation facility in Brazil.

This work describes the new facility for applied nuclear physics at the University of Sao Paulo, mainly for irradiation of electronic devices. It is a setup composed of a quadrupole doublet for beam focusing/defocusing plus multiple scattering through gold foils to produce low intensity, large-area, and high-uniformity heavy-ion beams from 1H to 107Ag. Beam intensities can be easily adjusted from 102 particles cm2/s to hundreds of nA for an area as large as 2.0 cm2 and uniformity better than 90%. Its irradiation chamber has a high-precision motorized stage, and the system is controlled by a LabViewTM environment, allowing measurement automation. Design considerations and examples of use are presented.

Oral Health and Quality of Life in Candidates for Liver Transplantation.

BACKGROUND: There is a gap in the scientific literature about the association between oral health and the health-related quality of life of patients on the liver transplantation waiting list. The aim of this work was to describe aspects of oral health and quality of life of patients on a liver transplantation waiting list. METHODS: This was a cross-sectional study among 116 patients with chronic hepatic disease: 29 on a liver transplantation waiting list (Model for End-Stage Liver Disease score ≥15) and 87 under monitoring in a gastroenterology service in a Brazilian university hospital. Oral health was evaluated according to criteria recommended by the World Health Organization and by the European Association of Dental Public Health. Health-related quality of life was evaluated by means of the 36-Item Short-Form Health Survey (SF-36). RESULTS: Patients on the liver transplantation waiting list presented poorer health-related quality of life than those who were not on the list in the domains physical functioning, role physical, bodily pain, general health perceptions, and social functioning and in the physical component summary. Periodontitis affected 72.4% of the patients on the liver transplantation waiting list, but only 27.6% of the patients not on that list. Reduced salivary flow was associated with poorer mental health component summary in hepatitis C patients. CONCLUSIONS: Patients on the liver transplantation waiting list presented poorer health-related quality of life than those who were not on the list, mainly in the indicators concerning physical health, as well as higher frequencies of decayed teeth and periodontitis. The mental health component summary was associated with reduced salivary flow in hepatitis C patients.

An environmentally safe larvicide against Aedes aegypti based on in situ gelling nanostructured surfactant systems containing an essential oil.

HYPOTHESIS: Liquid crystalline precursors, which are in situ gelling nanostructured surfactant systems, can undergo phase transition in aqueous solution and become more structured aggregates, controlling release of larvicides and acting as biotechnology alternatives for dengue control. Such systems can contain bioactive substances as Citrus sinensis essential oil (CSEO) which exhibits biological activity against Aedes aegypti (Ae. aegypti) larvae. EXPERIMENTS: The formulations were composed by fixed concentration of CSEO stabilized by Polyoxypropylene (5) Polyoxyethylene (20) Cetyl Ether (PPG-5 CETETH-20): oleic acid (OA) 2:1, increasing water content. The phase diagram was established and systems structure was evaluated by polarized light microscopy (PLM), small angle X-ray scattering (SAXS) and rheology. Median lethal concentration was determined against Ae. aegypti larvae. FINDINGS: The phase diagram exhibited four regions: liquid crystal (LC), emulsion, microemulsion (ME) and phase separation. The PLM and SAXS distinguished microemulsions, lamellar and hexagonal LC structures. Flow and oscillatory tests showed that increasing water content increases elasticity from Newtonian to non-newtonian behavior confirming the in situ gelation behavior. The larvicidal activity of formulations indicates that these nanostructured systems improved the oil solubility in aqueous medium and in addition are potential environmental larvicide against Ae. aegypti larvae.

Structural characterization and in vivo evaluation of retinyl palmitate in non-ionic lamellar liquid crystalline system.

Carrier systems for lipophilic drugs, such as the liquid crystalline systems (LCS) have been extensively studied to improve effect and selectivity. Retinyl palmitate (RP) is widely used in pharmaceutical and cosmetics products to improve the skin elasticity. The aim of this study was the development, characterization and the in vivo effectiveness of RP in non-ionic LCS structures. LCS containing polyether functional siloxane as oil phase, silicon glycol copolymer as surfactant and water in the ratio 30:10:60, with and without RP were studied. The results of the polarized light microscopy, small-angle X-ray scattering and rheology analysis indicated the presence of typical LCS structures with lamellar arrangement. Regardless of the presence of RP, the rheological studies showed the pseudo plastic behavior of the systems. However, highest hysteresis area was verified when comparing the system in the presence and in the absence of RP. Stability study SAXS monitored, carried out up to 30 days in various storage temperature conditions (25±2 °C, 37±2 °C and 5±2 °C) demonstrated the great structural stability of the LCS systems. The in vivo effectiveness analysis suggests that the RP-loaded LCS provided a significant reduction of the orbicular wrinkles in human volunteers (P=0.048).

Structure and viscoelastic behavior of pharmaceutical biocompatible anionic microemulsions containing the antitumoral drug compound doxorubicin.

Structure and viscoelastic properties of negatively charged oil-in-water (o/w) microemulsions have been investigated. Microemulsions (ME) containing soya phosphatidylcholine (SPC), eumulgin HRE 40 (EU) and sodium oleate (SO) as surfactant, cholesterol (CHO) as oil phase, and aqueous buffer with and without the antitumoral doxorubicin (DOX) have been studied. The effect of the oil phase/surfactant ratio (O/S) and the DOX incorporation on the structural and rheological properties have been studied in several compositions of ME systems. The rheological analyses were performed through the oscillation stress sweep, creep recovery test, and viscosity test. The combination of the DOX incorporation with the high O/S ratio provided a further viscoelastic structure with linear behavior. Independently of the O/S ratio the oil phase diameter increases according to a sigmoid profile, stabilizing up to 340 min. The apparent viscosity decreases a minimum value with the shear rate, but increases with both the O/S ratio and the DOX incorporation in the system. The structural and rheological properties of the studied MEs were directly dependent on the O/S ratio and can be used to improve the application of the system in the pharmaceutical field.

Oil-in-water lecithin-based microemulsions as a potential delivery system for amphotericin B.

In this work the structural features of microemulsions (MEs) containing the pharmaceutical biocompatible Soya phosphatidylcholine/Tween 20 (1:1) as surfactant (S), Captex 200 as oil phase (O), and phosphate buffer 10mM, pH 7.2 as aqueous phase (W) were studied. Systems obtained with different proportions of the components were described by pseudo-ternary phase diagrams in order to characterize the microemulsions studied here. MEs were prepared with and without the polyene antifungal drug amphotericin B (AmB). The maximum AmB incorporation into the ME system was dependent on both the oil phase and surfactant proportions with 6.80 and 5.7 mg/mL in high contents, respectively. The incorporation of AmB into the ME systems significantly increased the profile of the droplet size of the ME for all ranges of surfactant proportions used in the formulations. The microstructures of the system were characterized by dynamic light scattering (DLS) and rheological behavior. The DLS results showed that the size of the oil droplets increases 4.6-fold when AmB is incorporated into the ME system. In all cases the increase in the proportion of the oil phase of the ME leads to a slight increase in the diameter of the oil droplets of the system. Furthermore, for both the AmB-loaded and AmB-unloaded MEs, the size of the oil droplets decrease significantly with the increase of the S proportion in the formulations, demonstrating the efficiency of the surfactant in stabilizing the ME. Depending on the ME composition, an anti-thixotropic behavior was found. The maximum increases of the consistency index caused by the increase of the oil phase of the ME were of 17- and 25-times for the drug-loaded and drug-unloaded MEs, respectively. However, the observed effect for the drug-loaded ME was about 4.6 times higher than that for the drug-unloaded one, demonstrating the strong effect of the drug on the rheological characteristics of the ME system. Therefore, it is possible to conclude that the investigated ME can be used as a very promising vehicle for AmB.

Structural changes of biocompatible neutral microemulsions stabilized by mixed surfactant containing soya phosphatidylcholine and their relationship with doxorubicin release.

Depending on the composition, the mixture of surfactant, oil and water, may form supramolecular aggregates with different structures which can significantly influence the drug release. In this work several microemulsion (ME) systems containing soya phosphatidylcholine (SPC) and eumulgin HRE40 (EU) as surfactant, cholesterol (O) as oil phase, and ultra-pure water as an aqueous phase were studied. MEs with and without the antitumoral drug doxorubicin (DOX) were prepared. The microstructures of the systems were characterized by photon correlation spectroscopy, rheological behavior, polarized light microscopy, small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD). The results reveal that the diameter of the oil droplets was dependent on the surfactant (S) amount added to formulations. The apparent viscosity was dependent on the O/S ratio. High O/S ratio leads to the crystallization of cholesterol polymorphs phases which restricts the mobility of the DOX molecules into the ME structure. Droplets with short-range spatial correlation were formed from the ME with the low O/S ratio. The increase of the cholesterol fraction in the O/S mixture leads to the formation of ordered structures with lamellar arrangements. These different structural organizations directly influenced the drug release profiles. The in vitro release assay showed that the increase of the O/S ratio in the formulations inhibited the constant rate of DOX release. Since the DOX release ratio was directly dependent on the ratio of O/S following an exponential decay profile, this feature can be used to control the DOX release from the ME formulations.

Relationship between structural features and in vitro release of doxorubicin from biocompatible anionic microemulsion.

In this work structural features of anionic microemulsions, containing the pharmaceutical biocompatible components soya phosphatidylcholine (SPC), eumulgin HRE 40 (EU) and sodium oleate (SO) as surfactant, cholesterol (CHO) as oil phase and aqueous buffer were studied. Microemulsions were formulated with and without the antitumor drug doxorubicin (DOX). The various microstructures characterized in the pseudo-ternary phase diagram were analyzed by polarized light microscopy, small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) as well as by their ability to incorporate and release DOX. The experimental results demonstrated a correlation between the composition, the structural features and drug delivery. It was found that at higher cholesterol contents, the crystallization of CHO polymorph phases changed the mobility of DOX molecules. Droplets were formed with short-range spatial correlation from a microemulsion (ME) with a low surfactant:oil ratio. More ordered structures with lamellar arrangements formed by the increasing of the CHO proportions in the formulation may be due to CHO crystallization. The in vitro release of DOX showed that the presence of a high content of crystalline CHO prolongs the release of DOX from ME. The retention of DOX in the internal oil phase of the ME may modulate the drug release for a prolonged time. These results clearly demonstrate the potential of ME as a drug-delivery system.

Radiographic features of periodontal bone defects: evaluation of digitized images.

OBJECTIVES: Radiographic evaluation of periodontal conditions is a difficult process because of the many limitations inherent to this complementary examination and the lack of image specificity for different types of bone defects. The objectives of this study are to utilize digitized imaging resources to describe the radiographic features of different types of periodontal bone defects produced artificially in dry mandibles. METHODS: 14 dry mandibles were utilized, in which periodontal bone defects were produced. Digital photographs and conventional radiographs of each site were obtained in a standardized manner, before and after producing these defects. The radiographs were then digitized, displayed on the screen and evaluated by three examiners. RESULTS: Most of the bone defects presented distinct imaging characteristics that allowed them to be identified, with the exception of one-, two- and three-wall infrabony defects. The defects that were most easily interpreted were horizontal and vertical defects and the most difficult were defects in the radicular septum. CONCLUSIONS: Despite the importance of imaging diagnoses in reaching clinical decisions regarding treatment, such diagnoses for different types of periodontal bone defects are extremely difficult to make. In the present study, the utilization of digital tools for interpreting digitized radiographic images facilitated the process.

Doxorubicin biocompatible O/W microemulsion stabilized by mixed surfactant containing soya phosphatidylcholine.

Microemulsions (ME) containing soya phosphatidylcholine (SPC)/polyoxyethylenglycerol trihydroxystearate 40 (EU)/sodium oleate (SO) as surfactant cholesterol (CHO) as oil phase and aqueous buffer were studied. Pseudo-ternary phase diagrams of the investigated systems were obtained at constant SPC/EU/SO weight ratio 3.5:3.5:3.0 by titration, in order to characterize the proportions between the components to form clear systems. The dynamic light scattering results showed that the size of the oil droplets decreases significantly with the ratio of surfactant/oil phase added to system. Depending on the composition ME system could exhibit a thixotropic behavior. The apparent viscosity increased 25- and 13-folds with cholesterol concentration for drug-free and drug-load ME, respectively. It was also verified that the octanol/aqueous buffer partition coefficient (KO/B) of doxorubicin (DOX) was pH dependent increasing abruptly above pH 6.0. It was possible to incorporate 2.24 mg/ml of DOX into ME. The incorporation of DOX in the ME systems increased the droplets size for all surfactant concentrations used in the system. The results suggest that DOX interacts with the microstructure of the ME at the studied pH increasing significantly the drug solubility. It was possible to conclude that the investigated ME can be a very promising vehicle as drug-carrier for administration of doxorubicin.

Contribuiçäo ao estudo da anatomia do sistema de canais radiculares de caninos inferiores utilizando-se de cortes macroscópicos e da diafanizaçäo / Anatomy study of root system of lower canines using macroscopic cuts and clarifying technique

A anatomia dos canais radiculares tem sido tema de estudos desde 1942 e mesmo com as diversas observaçöes descritas por vários autores, permaneceu-se dúvidas a respeito dos aspectos morfológicos internos de vários grupos de dentes. O presente trabalho utilizou-se de 103 (cento e três) caninos interiores extraídos, onde se analisou os aspectos macroscópicos da cavidade pulpar, utilizando-se de cortes sagital, frontal e transversais, assim como da diafanizaçäo. Notamos que, em 100 po cento dos espécimes haviam uma raiz e um único canal radicular, sendo que em 83 por cento das amostras evidenciou-se permeabilidade dentinária. Os canais secundários foram verificados em 47 por cento dos dentes, assim com 3 por cento de canais laterais, 1 por cento canal acessório e 15 por cento co delta apical. fator importante que observamos também foi que, em 42 dos espécimes o forame apical coincidia-se com o ápice radicular; 23 por cento, abria-se para vestibular, 8 por cento, para distal; 8 por cento, para mesial e 4 por cento para lingual