Orbscan II and double-K method for IOL calculation after refractive surgery

Precise IOL calculation in post-refractive surgery patients is still a challenge for the cataract surgeon. the purpose of this study is to test whether adding Orbscan II values into the double-K method improves IOL calculation in this group of patients.A prospective study with 43 eyes previously submitted to refractive surgery that underwent cataract extraction. IOL calculation was performed with double-K method. Post-K value was derived from Orbscan total-mean power map. the average corneal curvature of the general population (43.8D) was used as the pre-K value. Refraction results 30 days after surgery were compared with refraction that would be obtained if we used: (1) post-K values from keratometry, (2) post-K values from topography, and (3) pre-K values from Orbscan total-mean power. Anterior chamber depth measures obtained with the IOL Master and Orbscan II were compared.Mean postoperative spherical equivalent (SE) was -0.25 +/- 1.10 D in eyes submitted to radial keratotomy , -1.04 +/- 1.42 D in eyes previously submitted to myopic Lasik, and +0.05 +/- 1.76 D in those submitted to hyperopic surgeries. Had we inputted post-K values derived from keratometer and from topography, we would have obtained significantly higher postoperative refractive errors in eyes previously submitted to myopic refractive surgery (p 0.05). Anterior chamber depth measured with IOL Master or Orbscan were similar.Orbscan measurements used as the post-K values into the double-K method provide a precise IOL calculation, especially in post myopic refractive surgery patients.Univ Fed Rio Grande do Sul, Dept Ophthalmol, Hosp Clin Porto Alegre, BR-90470000 São Paulo, BrazilOftalmoCentro, Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilWeb of Scienc

Anatase nanoparticles on supergene platinum-palladium aggregates from Brazil: Titanium mobility in natural waters

Supergene aggregates of platinum-palladium (Pt-Pd) intermetallic compounds from the Córrego Bom Sucesso alluvial deposit, Minas Gerais, Brazil, are coated with abundant, poorly crystalline nanoparticles of anatase (TiO2). The anatase coating is widespread, suggesting that the surface of the Pt-Pd grains catalytically destabilised Ti, which was likely dissolved by organic ligands in the ground waters. Association of TiO2 nanocrystallites with organic matter further suggests that biogenic processes could have mediated their formation. These anatase-coated Pt-Pd grains demonstrate an unexpected Ti mobility in supergene environments. © 2012 Elsevier B.V.Alexandre Raphael Cabral, Frank Reith, Bernd Lehmann, Joël Brugger, Guido Meinhold, Miguel Tupinambá, Rogerio Kwitko-Ribeir

Intercorrência audiológica em músicas após um show de rock Hearing incidents in musicians after a rock concert

OBJETIVO: verificar mudança temporária do limiar de audição de músicos, após exposição a níveis de pressão sonora elevados de um show de rock. MÉTODOS: foi utilizada uma amostra com seis músicos componentes da banda. Foram feitos: anamnese ocupacional, determinação dos níveis mínimos de audição e reflexos acústicos, antes e após o show de rock. A mensuração do ruído da sala do exame e do palco foi realizada por meio de um dosímetro. Os resultados foram comparados e analisados estatisticamente, utilizando-se o teste t Student, com critério para determinação de significância de p maior do que 0,05. RESULTADOS: para a dosimetria, foi encontrada a exposição ao ruído do show com valor de LAVG igual a 98,5 dB. Dentre os aspectos comportamentais relacionados ao ruído, o zumbido foi a queixa mais presente entre os integrantes. Na audiometria tonal, as maiores diferenças pré e pós-exposição, foram encontradas nas freqüências altas, sendo a orelha direita a que apresentou maiores mudanças temporárias de limiar. Os resultados foram significantes nas freqüências de 2000, 3000, 4000 e 6000 Hz, na orelha direita (p=2,7; p=2,59; p=3,7 e p=2,86) e, na freqüência de 4000 Hz, na orelha esquerda (p=2,87). Na medida do reflexo acústico após o show, a orelha direita obteve o maior índice de ausência de reflexo, com o índice de 40%; entretanto, foram encontradas diferenças estatisticamente significantes, na presença de reflexo acústico na comparação pré e pós-exposição, apenas na orelha esquerda (p=3,64). CONCLUSÃO: músicos expostos a níveis de pressão sonora intensos apresentaram alteração temporária do limiar e alteração do reflexo acústico.<br>PURPOSE: verifying the temporary threshold shift in musicians after a high sound pressure level music exposure in a rock concert. METHODS: the sample has been made up of six band's musicians, who underwent an occupational anamnesis, pure tone audiometry and acoustic reflex measurements, before and after the rock concert. The noise levels of the room and the stage were determined by means of a dosimeter. The results were compared and statically analyzed using the t Student test with significance criterion of p> 0.05. the noise level found in the room and stage during the concert was 98.5 dB. As for the behavioral aspects related to the noise, tinnitus was the most prevalent complaint among the subjects. In pure tone audiometry, statistically significant differences were found in the hearing thresholds, before and after exposure, mostly in the right ear for the high frequencies. The results were also statistically significant at the frequencies between 2000Hz and 6000Hz, for the right ear (p=2.7; p=2.59; p=3.7 e p=2.86), and at the frequency of 4000Hz, for the left ear (p=2.87). The right ear's acoustic reflex has shown the highest index of absence (40%); however, we found statistically significant differences in the presence of the acoustic reflex, before and after exposure, only for the left ear (p=3.64). CONCLUSION: musicians exposed to high sound pressure levels in rock concerts have shown temporary threshold shift at the pure tone audiometry and acoustic reflex measurements