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BACKGROUND: Peritonsillar abscess is the most common deep infection of the head and neck in young adults. It is considered a purulent complication of acute tonsillitis, but other mechanisms have been proposed. There is no consensus as to whether seasonality affects peritonsillar abscess incidence. METHODS: This observational, descriptive, retrospective study explored the epidemiology of peritonsillar abscess and its relationship with seasonality. The cases were selected from the emergency otolaryngology service of a tertiary hospital. RESULTS: The sample comprised 528 patients (42.61 per cent males, mean age = 26.63 years). A moderate positive correlation was found between peritonsillar abscess incidence and monthly average temperature. No associations were found with insolation, precipitation or humidity. CONCLUSION: In this sample, peritonsillar abscess was more likely to occur in warmer months. The findings corroborate the theory that peritonsillar abscess is not a direct complication of acute tonsillitis and may improve understanding of peritonsillar abscess aetiology.

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The present work reports the production of films on AA2024-T3 composed of vinyltrimethoxysilane (VTMS)/tetraethylorthosilicate (TEOS) with incorporation of montmorillonite (sodium montmorillonite and montmorillonite modified with quaternary ammonium salt, abbreviated Na and 30B, respectively), generated by the sol-gel process. According to FT-IR analyses the incorporation of montmorillonite does not affect silica network. Electrochemical characterization was performed by electrochemical impedance spectroscopy measurement in 0.05 mol L(-1) NaCl solution. Results indicate that montmorillonite incorporation improves the corrosion protection compared to the non-modified system. Scanning electron microscopy micrographs reveal that high concentrations of montmorillonite provide agglomerations on the metallic surface, which is in detriment of the anticorrosive performance. The VTMS/TEOS/30B films with the lowest concentration (22 mg L(-1)) of embedded clay provide the highest corrosion protection.

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Metal (Fe, Mn, Zn, Ni, Cd, and Pb) concentrations in the region of Criciuma (Brazil), a region impacted by coal mining, were determined in water and sediments using total reflection X-ray fluorescence (TXRF) spectroscopy. Samples were collected from the Mãe Luzia River (south Brazil) at five different stations, from the source down to the river mouth (Ararangua estuary). Water and sediment toxicity were also evaluated using bioassays with Daphnia magna as the bioindicator. The metal present in the highest concentrations both in water (1.3-11 mg L(-1)) and in sediments (34-142 mg L(-1)) was iron. Results suggest an influence of coal mining on the aquatic receptors, showing a clear relationship between metal content (mostly Fe) and ecotoxicity.

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Thermal decomposition studies of the free polyhedral oligomeric silsesquioxane, POSSh, and when this compound has been impregnated with Cp2ZrCl2 (Cp = eta5-C5H5) or immobilized on SiO2 were conducted using infrared emission spectroscopy (IES) over a 100-1000 degrees C temperature range and by thermogravimetric analysis (TGA). The organic groups in POSS(h) apparently decompose thermally into Si-CH3, Si-H and other fragments. Upon impregnation with Cp2ZrCl2, however, a different thermal decomposition pathway was followed and new infrared emission bands appeared in the 1000-900 cm(-1) region suggesting the formation of Si-O-Zr moieties. When immobilized on SiO2 and subjected to thermal decomposition, the POSSh compound lost its organic groups and the inorganic structure remaining was incorporated into the SiO2 framework.

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FT-IR photoacoustic and Raman spectroscopy have been used to study the interactions between the metallocene catalyst, Cp(2)ZrCl(2) (Cp=eta(5)-C(5)H(5)), and two polyhedral oligomeric silsesquioxanes (POSS) supports. The first silsesquioxane support, POSS(h), contains (beta-hydroxyl)-tertiary amine groups, while in the second one, POSS(u), these -OH groups have been converted into N-(p-toluyl) urethane groups. The vibrational spectra of the Cp(2)ZrCl(2):POSS(h) and Cp(2)ZrCl(2):POSS(u) samples show that the Cp(2)ZrCl(2) catalyst reacts with the C-OH groups of POSS(h) and also interacts with N-H and >CO groups of POSS(u). Furthermore, Cp(2)ZrCl(2) can react with the Si-OH groups of the POSS supports and also interact with the O atoms that are bonded to the benzene rings and the N atoms of the tertiary amines in both silsesquioxanes. As a result of the interactions between Cp(2)ZrCl(2) and the POSS supports, acidic species are generated. The Cp(2)ZrCl(2):POSS(h) mass ratio seems to be an important parameter in the formation of Zr-O bonds and the acidic species.

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OBJECTIVES: To determine the prevalence and distribution of primary venous reflux in the lower limbs in patients without truncal saphenous reflux. DESIGN: Prospective cohort study. PATIENTS AND METHODS: One thousand and seven hundred and twelve patients with suspected venous disease were examined by duplex ultrasonography. Seven hundred and thirty-five patients had primary varicose veins with competent saphenous trunks. Limbs with truncal saphenous reflux, deep vein reflux or obstruction, previous injection sclerotherapy or vein surgery, arterial disease and inflammation of non-venous origin were excluded from further consideration. The CEAP classification system was used for clinical staging. Systematic duplex ultrasound examination was undertaken to assess the distribution of incompetent saphenous tributaries. RESULTS: The prevalence of primary reflux with competent saphenous trunks was 43%. Reflux of GSV calf tributaries was the most common. The majority of the limbs (96%) belonged to chronic venous disease classes C1 and C2 of the CEAP classification. CONCLUSIONS: Superficial venous reflux causing varicose veins in the presence competent saphenous trunks is very prevalent in this series in contrast to other studies, presumably reflecting differing patient populations. Our data clearly show that varicose veins may occur in any vein and do not depend on truncal saphenous incompetence. Careful duplex ultrasound evaluation allows the pattern of venous reflux to be established in this group of patient ensuring appropriate management of varices.

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