Influence of fluoride-containing solutions on the translucency of flowable composite resins

The aim of this study was to evaluate the influence of fluoride-containing solutions on the translucency of flowable composite resins, with respect the immersion time. Flow-It! (FI) and Natural Flow (NF) composite resins and three commercial brands of fluoride-containing solutions (Fluordent, Fluorgard and Oral B) were used. Specimens were prepared and stored in the solutions at 37°C, until the measurements were made after the following treatments: T1 - after 1 hour in relative humidity; T2 - after 1 h in solution; T3 - 24 h; T4 - 48 h; T5 - after a week; from T9, the measurements were accomplished weekly, up to 30-day immersion. To obtain translucency values an electrophoresis equipment was employed. Data were submitted to ANOVA and Tukey tests. The results disclosed that NF showed highest values of translucency and was statistically different from FI (p< 0.001). As regards the solutions, Fluordent and Oral B presented similar values and were statistically superior to Fluorgard (p< 0.05). Concerning the immersion time, similar results were observed for the different evaluation periods. It may be concluded that the fluoride-containing solutions affected the translucency of the composite resins, independently of the materials used. Among the tested resins, NF presented the best performance.     

Fine-needle aspiration cytology of the breast: a preliminary report on telepathology through Internet multimedia electronic mail

BACKGROUND AND AIMS OF THE STUDY: Tricuspid valve endocarditis traditionally has been treated with either valve resection or valve replacement. To avoid implantation of foreign material in an infected area and to circumvent anticoagulation, tricuspid valve repair was applied and the results assessed. METHODS: Tricuspid valve repair was performed in five patients with right-sided endocarditis. All patients had tricuspid regurgitation grade 3-4 on preoperative transesophageal echocardiography, and developed progressive deterioration associated with heart failure. The indications for surgery were congestive heart failure, persistent sepsis, recurrent emboli, concomitant left-sided endocarditis, and fungal infection. Surgical procedures included cusp resection, annular plication and annuloplasty, pericardial patch replacement, and construction of artificial chordae. RESULTS: There were no hospital deaths and major associated morbidity. Follow up is complete at a mean of 20.4 months. There were no reoperations or cases of recurrent infections. All patients are in NYHA class I-II. Postoperative echocardiography revealed no signs of major valvular dysfunction. CONCLUSIONS: Valve repair in right-sided endocarditis is a relatively new application for repair techniques, but may become an attractive alternative to tricuspid valve excision or prosthetic valve replacement.     

In vitro synthesis of prostaglandin E2 by synovial tissue after helium-neon laser radiation in rheumatoid arthritis

This paper reports the effect of helium-neon laser radiation (power of 5 mW and 632.8 nm wave length) on the synthesis of PGE2 in vitro in synovial tissue of biopsy samples of knee joints in patients with chronic rheumatoid arthritis stages II or III. Twelve patients were studied. Each patient received 15 applications of He-Ne laser. Eleven points for He-Ne laser applications were selected in one of the affected knees. The energy density used was 8 J/cm2 per application point. The He-Ne laser therapy reduced the synthesis of PGE2. The analysis of the data revealed a statistically significant difference between the levels of the synthesis of PGE2 before treatment (17.69 +/- 2.65 ng mg-1 of dry tissue h-1) and after treatment (13.85 +/- 2.73 ng mg-1 of dry tissue h-1), with p < 0.01 comparing mean values. This was also accompanied by relief of pain (91.6%), and a favorable subjective report from the patient. We conclude that PGE2 is a quantifiable parameter that could explain what causes pain relief in patients with rheumatoid arthritis that are treated with He-Ne laser.     

New Magnetic Polymer Nanocomposites on the Basis of Isotactic Polypropylene and Magnetite Nanoparticles for Adsorption of Ultrahigh Frequency Electromagnetic Waves

In this study, we report about the preparation of magnetic polymer nanocomposites on the basis of isotactic polypropylene and magnetite Fe₃O₄ nanoparticles. The structure and composition of polymer nanocomposite materials have been studied by scanning electron microscopy, atomic force microscopy, and X-ray dispersive analysis. The magnetic properties of polymer nanocomposites based on PP+Fe₃O₄have been investigated. It is found that not significant adhesion and agglomeration of nanoparticles occur, by increasing the nanoparticle content in polymer matrix up to 40%, and therefore they act as single-domain nanoparticles. The samples of nanocomposites based on PP+Fe₃O₄, with up to 40% content of Fe₃O₄, exhibit superparamagnetic properties. It was also found out that the magnetic polymer nanocomposite material based on PP+Fe₃O₄ is able to absorb ultrahigh frequency electromagnetic waves in the frequencies range from 0.1 to 30?GHz. The increase in Fe₃O₄ concentration from 5 to 40% at the 400?µm thicknesses of the films leads to an increase in absorption of electromagnetic waves of high frequency from 15 to 22.7%.     

A neutron diagnostic for high current deuterium beams

A neutron diagnostic for high current deuterium beams is proposed for installation on the spectral shear interferometry for direct electric field reconstruction (SPIDER, Source for Production of Ion of Deuterium Extracted from RF plasma) test beam facility. The proposed detection system is called Close-contact Neutron Emission Surface Mapping (CNESM). The diagnostic aims at providing the map of the neutron emission on the beam dump surface by placing a detector in close contact, right behind the dump. CNESM uses gas electron multiplier detectors equipped with a cathode that also serves as neutron-proton converter foil. The cathode is made of a thin polythene film and an aluminium film; it is designed for detection of neutrons of energy >2.2 MeV with an incidence angle < 45°. CNESM was designed on the basis of simulations of the different steps from the deuteron beam interaction with the beam dump to the neutron detection in the nGEM. Neutron scattering was simulated with the MCNPX code. CNESM on SPIDER is a first step towards the application of this diagnostic technique to the MITICA beam test facility, where it will be used to resolve the horizontal profile of the beam intensity.     

Arthroscopic treatment of anterior ankle impingement

Ankle arthroscopy has recently allowed the elaboration of less invasive techniques for the treatment of anterior impingement. Its indications, advantages, and drawbacks in this application are discussed. Between 1987 and 1994, 133 patients were treated for ankle impingement. Among them, 58 patients, 37 men and 21 women (mean age, 28.5 years), who had failed a trial of conservative treatment were treated by means of tibiotalar arthroscopy. Twenty-seven were athletes engaged in sports with abnormal stressing of the ankle. According to McDermott's radiological classification, there were 15 stage I cases, 23 stage II, 13 stage III, and 7 stage IV. Preoperative evaluation with a modified version of McGuire's scoring system gave 50 cases rated as "poor" (< 60 points) and 8 cases rated as "fair" (60-67 points). Treatment consisted of removal of adhesions, cartilage shaving, and removal of the bone impingement with powered instruments, curettes, or small osteotomes. Follow-up was from 8 to 62 months (mean, 21.5 months). The postoperative McGuire ratings were 37 good, 13 fair, and 8 poor. There were no major complications. Recurrence of impingement was observed in four cases of stage III and IV. The conclusion is drawn that ankle arthroscopy is a sound method for the treatment of anterior impingement. Even in cases with severe joint cartilage impairment, it plays a therapeutic role as a means of postponing a possible arthrodesis.     

A dialogue-based approach for dealing with uncertain and conflicting information in medical diagnosis

In this paper, we propose a multi-agent framework to deal with situations involving uncertain or inconsistent information located in a distributed environment which cannot be combined into a single knowledge base. To this end, we introduce an inquiry dialogue approach based on a combination of possibilistic logic and a formal argumentation-based theory, where possibilistic logic is used to capture uncertain information, and the argumentation-based approach is used to deal with inconsistent knowledge in a distributed environment. We also modify the framework of earlier work, so that the system is not only easier to implement but also more suitable for educational purposes. The suggested approach is implemented in a clinical decision-support system in the domain of dementia diagnosis. The approach allows the physician to suggest a hypothetical diagnosis in a patient case, which is verified through the dialogue if sufficient patient information is present. If not, the user is informed about the missing information and potential inconsistencies in the information as a way to provide support for continuing medical education. The approach is presented, discussed, and applied to one scenario. The results contribute to the theory and application of inquiry dialogues in situations where the data are uncertain and inconsistent.