Determination of fluorine in tea using high-resolution molecular absorption spectrometry with electrothermal vaporization of the calcium mono-fluoride CaF.

High-resolution continuum source molecular absorption of the calcium mono-fluoride molecule CaF in a graphite furnace has been used to determine fluorine in tea after acid digestion, alkaline solubilization and preparation of a conventional aqueous infusion. The strongest absorption 'line' of the CaF molecule is at 606.440 nm, which is part of the rotational fine structure of the X(2)Σ(+)-A(2)Π electronic transition; it has a bond dissociation energy of 529 kJ mol(-1), which is comparable with other molecules used for fluorine determination. One advantage of using Ca as the molecule-forming reagent is that spectral interferences are extremely unlikely in the spectral range of its strongest absorption. Another advantage is that Ca acts both as molecule forming reagent and chemical modifier, so that no other reagent has to be added, making the method very simple. The only disadvantage is that Ca has a somewhat negative influence on the graphite tube lifetime. The limit of detection was found to be 0.16 mg L(-1) F, corresponding to 1.6 ng F absolute, and the calibration curve was linear in the range between 0.5 and 25 mg L(-1) with a correlation coefficient of R=0.9994. The results obtained for a certified tea reference material were in agreement with the certified value on a 95% confidence level. There was also no difference between the results obtained after an acid digestion and an alkaline solubilization for 10 tea samples, based on a paired t-test. The values found in the 10 samples ranged between 42 µg g(-1) and 87 µg g(-1) F; the tea infusions contained between 21 µg g(-1) and 56 µg g(-1) F, with an extraction rate between 48% and 74%.

Absorbable versus nonabsorbable sutures for the arthroscopic treatment of anterior shoulder instability in athletes: a prospective randomized study.

PURPOSE: The purpose of this study was to compare the functional results of arthroscopic treatment for traumatic anterior shoulder instability in 2 groups of athletes. METHODS: Fifty patients were randomly assigned to 2 different groups with comparable patient demographics. Group A was treated with anchors loaded with absorbable sutures, and group B was treated with the same type of anchors loaded with nonabsorbable sutures. The same type of absorbable anchor, surgical technique, and rehabilitation protocol was used in both groups. The outcomes were evaluated after a minimum postoperative period of 24 months. The Rowe score and the Athletic Shoulder Outcome Scoring System were applied, and statistical analysis was performed. RESULTS: The mean Rowe score was 83.8 in group A and 79.5 in group B. The mean values for the Athletic Shoulder Outcome Scoring System were 84 and 79.2, respectively. Good or excellent results were found in 90.5% of patients in group A and 87.5% in group B. We had 2 failures (9.5%) in group A and 3 (12.5%) in group B. No statistically significant difference was found in the comparison of the outcomes (P > .05). CONCLUSIONS: The type of suture used, absorbable or nonabsorbable, did not influence the functional results of arthroscopic treatment for traumatic anterior shoulder instability in this series.

Tratamento das fraturas do terço proximal do úmero com a prótese parcial Eccentra® / Treatment of proximal third of humerus fractures with Eccentra® partial prosthesis

O tratamento das fraturas graves do terço proximal do úmero pela artroplastia parcial leva, segundo a literatura, a resultados funcionais limitados. Com o objetivo de tentar melhorar esses resultados, um modelo de prótese que permite melhor reconstrução da anatomia do terço proximal do úmero foi desenvolvido e foi chamada de Eccentra. Entre fevereiro de 1996 e julho de 2000, 54 ombros de 53 pacientes com fraturas graves do terço proximal do úmero foram submetidos a artroplastia parcial. Desses, foram reavaliados 42 ombros de 41 pacientes, com segui- mento médio de 26 meses. A idade dos pacientes na época da lesão foi, em média, de 65 anos. Pelo sistema de pontuação da UCLA, observaram-se 40 por cento de excelentes e bons resultados e 60 por cento de resultados insatisfatórios, semelhantes aos descritos na literatura. Observaram-se também 10 por cento de complicações. Os autores concluem que a artroplastia parcial para o tratamento das fraturas graves do terço proximal do úmero leva a resultados satisfatórios no que se refere à dor e satisfação dos pacientes, e que a utilização do implante modular, especialmente desenhado para o tratamento dessas fraturas, aliada a uma técnica de sutura dos tubérculos mais eficiente, pode melhorar esses resultados