Poluentes orgânicos persistentes em ar interior: desenvolvimento de método de extração em adsorvente para amostragem ativa

Persistent Organic Pollutants (POPs) are chemical substances extraordinarily toxic and persistent in the environment. Due to these properties, POPs are targets of the Stockholm Convention which aims to provide means to eliminate production and use by encouraging the reduction and, where possible, eliminating the release of these contaminants to the environment. One of the articles of this _Convention aims to assess the basal levels of such substances in the environment to monitor both the reduction of release to the environment, and to assess human exposure, using analyzes of milk and air for example. Although efforts to control POPs production and release to the environment have been made, data about their levels in Brazil are still scarce, mainly in the atmosphere or indoor environment. Considering the permanence of people inside its house, this study presents a method for POP extraction from XAD-2 sorbent employed in indoor air sampling, with identification and quantification by GC-ECD. GC-ECD linear range of the studied analytes, congeners of polychlorinated biphenyls (PCB) (28, 52, 101, 118, 138, 153 and 180), DDTs and their metabolites (DDDs, DDEs) and endosullan (isomers c - and 13 - and metabolite endosulfan sulfate) ranged between 0.5 and 16.0 ng mL-I with r2 > 0.967. The method developing consist of selecting the extraction solvent system by agitation (90 rpm, 1 hour) with n-hexan,e (2 mL) or n-hexane:acetone (1:1, v/v) (2 mL), concentration the extract with a gentle N2 stream, and evaluation of breakthrough with passage or air through the fortified XAD-2 cartridge before extraction, employing a low volume air suction pump (Pump Model 224 universal-PCXR8; 5-5000 mL min-1, SKC Inc., Eighty Four, PA, USA), Calibrator Dry-Cal DC-Lite (BIOS, Butler, NJ, USA)). Two fortification levels were employed, 15 and 30 ng. After selecting n-hexane as extraction solvent, with accuracy and precision ranging...

Composite resin color stability: influence of light sources and immersion media

This study evaluated the influence of light sources and immersion media on the color stability of a nanofilled composite resin. Conventional halogen, high-power-density halogen and high-power-density light-emitting diode (LED) units were used. There were 4 immersion media: coffee, tea, Coke® and artificial saliva. A total of 180 specimens (10 mm x 2 mm) were prepared, immersed in artificial saliva for 24 h at 37±1ºC, and had their initial color measured with a spectrophotometer according to the CIELab system. Then, the specimens were immersed in the 4 media during 60 days. Data from the color change and luminosity were collected and subjected to statistical analysis by the Kruskall-Wallis test (p<0.05). For immersion time, the data were subjected to two-way ANOVA test and Fisher's test (p<0.05). High-power-density LED (ΔE=1.91) promoted similar color stability of the composite resin to that of the tested halogen curing units (Jet Lite 4000 plus--ΔE=2.05; XL 3000--ΔE=2.28). Coffee (ΔE=8.40; ΔL=-5.21) showed the highest influence on color stability of the studied composite resin. There was no significant difference in color stability regardless of the light sources, and coffee was the immersion medium that promoted the highest color changes on the tested composite resin.

Storage media for avulsed teeth: a literature review

Dental avulsion is the most severe type of traumatic tooth injuries because it causes damageto several structures and results in the complete displacement of the tooth from its socketin the alveolar bone. The ideal situation is to replant an exarticulated tooth immediatelyafter avulsion because the extraoral time is a determinant factor for treatment successand for a good prognosis. However, it is not always possible. The success of replantationdepends on a number of factors that may contribute to accelerate or minimize theoccurrence of root resorption or ankylosis, among which is the type and characteristicsof the medium used for temporary storage during the time elapsed between avulsionand replantation. Maintaining the tooth in an adequate wet medium that can preserve,as longer as possible, the vitality of the periodontal ligament cells that remain on rootsurface is the key to success of replantation. Recent research has led to the developmentof storage media that produce conditions that closely resemble the original socketenvironment, with adequate osmolality (cell pressure), pH, nutritional metabolites andglucose, and thus create the best possible conditions for storage. Although these storagemedia can now be purchased in the form of retail products, the most common scenariois that such a product will not be readily available at the moment of the accident Thispaper reviews the literature on the different storage media that have been investigatedfor avulsed teeth based on full-length papers retrieved from PubMed/Medline, Lilacs, BBOand SciELO electronic databases using the key words storage medium , transportationmedium , avulsion , tooth avulsion , replantation , tooth replantation , milk and propolis .After application of inclusion and exclusion criteria, 39 papers were selected and criticallyreviewed with respect to the characteristics, efficacy and ease of access of the storagemedium. The review of the lite

As cortinas que cerram o Vale: religião e secularização na diocese de Limoeiro do Norte/CE (1940-1980)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação dos protocolos de diagnóstico e de controle da hiperglicemia materna: impacto na prevalência de Diabetes Melito Gestacional (DMG) e de Hiperglicemia Gestacional Leve (HGL) e nos resultados perinatais

Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB