Comparison of the fracture resistance of endodontically treated teeth restored with prefabricated posts and composite resin cores with different post lenghts

OBJECTIVE: This study evaluated the fracture strengths of endodontically treated teeth restored with prefabricated posts with different post lengths. MATERIAL AND METHODS: Thirty freshly extracted canines were endodontically treated. They were randomly divided into groups of 10 teeth and prepared according to 3 experimental protocols, as follows; Group 1/3 PP: teeth restored with prefabricated post and composite resin core (Z250) with post length of 5.0mm; Group 1/2 PP and Group 2/3 PP: teeth restored with prefabricated post and composite resin core (Z250) with different combinations of post length of 7.5mm and 10mm, respectively. All teeth were restored with full metal crowns. The fracture resistance (N) was measured in a universal testing machine (crosshead speed 0.5mm/min) at 45 degrees to the tooth long axis until failure. Data were analyzed by one-way analysis of variance (alpha=.05). RESULTS: The one-way analysis of variance demonstrated no significant difference among the different post lengths (P>;.05) (Groups 1/3 PP = 405.4 N, 1/2 PP = 395.6 N, 2/3 PP = 393.8 N). Failures occurred mainly due to core fracture. CONCLUSIONS: The results of this study showed that an increased post length in teeth restored with prefabricated posts did not significantly increase the fracture resistance of endodontically treated teeth

Rapid increase of Plasmodium falciparum dhfr/dhps resistant haplotypes, after the adoption of sulphadoxine-pyrimethamine as first line treatment in 2002, in southern Mozambique

<p>Abstract</p> <p>Background</p> <p>In late 2002, the health authorities of Mozambique implemented sulphadoxine-pyrimethamine (SP)/amodiaquine (AQ) as first-line treatment against uncomplicated falciparum malaria. In 2004, this has been altered to SP/artesunate in line with WHO recommendations of using Artemisinin Combination Therapies (ACTs), despite the fact that all the neighbouring countries have abandoned SP-drug combinations due to high levels of SP drug resistance. In the study area, one year prior to the change to SP/AQ, SP alone was used to treat uncomplicated malaria cases. The study described here investigated the immediate impact of the change to SP on the frequency of SP and CQ resistance-related haplotypes in the <it>Plasmodium falciparum </it>genes <it>Pfdhfr, Pfdhps </it>and <it>Pfcrt </it>before and a year after the introduction of SP.</p> <p>Methods</p> <p>Samples were collected during two cross sectional surveys in early 2002 and 2003 involving 796 and 692 children one year or older and adults randomly selected living in Maciana, an area located in Manhiça district, Southern Mozambique. Out of these, 171 and 173 <it>P. falciparum </it>positive samples were randomly selected to measure the frequency of resistance- related haplotypes in <it>Pfdhfr, Pfdhps </it>and <it>Pfcrt </it>based on results obtained by nested PCR followed by sequence-specific oligonucleotide probe (SSOP)-ELISA.</p> <p>Results</p> <p>The frequency of the SP-resistance associated <it>Pfdhps </it>double mutant (SGEAA) haplotype increased significantly from 14% to 35% (P < 0.001), while the triple mutant <it>Pfdhfr </it>haplotype (CIRNI) remained high and only changed marginally from 46% to 53% (P = 0.405) after one year with SP as first-line treatment in the study area. Conversely, the combined <it>Pfdhfr/Pfdhps </it>quintuple mutant haplotype increased from 8% to 26% (P = 0.005). The frequency of the chloroquine resistance associated <it>Pfcrt</it>-CVIET haplotype was above 90% in both years.</p> <p>Conclusion</p> <p>These retrospective findings add to the general concern on the lifespan of the combination of SP/artesunate in Mozambique. The high frequency of quintuple <it>Pfdhfr</it>/<it>Pfdhps </it>haplotypes found here as early as 2002 most likely cause ideal conditions for the development of artesunate tolerance in the <it>P. falciparum </it>populations and may even endanger the sensitivity to the second-line drug, Coartem^®.</p

Divergent Biochemical Fractionation, Not Convergent Temperature, Explains Cellulose Oxygen Isotope Enrichment across Latitudes

Recent findings based on the oxygen isotope ratios of tree trunk cellulose indicate that the temperature of biomass production in biomes ranging from boreal to subtropical forests converge to an average leaf temperature of 21.4°C. The above conclusion has been drawn under the assumption that biochemically related isotopic fractionations during cellulose synthesis are not affected by temperature. Here we test the above assumption by heterotrophically generating cellulose at different temperatures and measuring the proportion of carbohydrate oxygen that exchange with water during cellulose synthesis and the average biochemical fractionation associated with this exchange. We observed no variation in the proportion of oxygen that exchange with different temperatures, which averaged 0.42 as it has been observed in other studies. On the other hand, the biochemical oxygen isotope fractionation during cellulose synthesis is affected by temperature and can be described by a 2nd order polynomial equation. The biochemical fractionation changes little between temperatures of 20 and 30°C averaging 26‰ but increases at lower temperatures to values of 31‰. This temperature sensitive biochemical fractionation explains the pattern of cellulose oxygen isotope ratios of aquatic plants encompassing several latitudes. The observed temperature sensitive biochemical fractionation also indicates that divergent biochemical fractionation and not convergent leaf temperature explains the increase in oxygen isotope enrichment of cellulose across several biomes

Os mártires e a cristianização do território na América portuguesa, séculos XVI e XVII

O artigo investiga um grupo de atores sociais bastante relevante para viabilizar a cristianização na América portuguesa: os mártires cristãos, indivíduos muito especiais, dispostos a regar a terra com seu próprio sangue, de forma a tornar definitiva e irreversível a ocupação cristã do território. Os mártires - e principalmente a narrativa em torno deles - parecem ter sido bastante acionados para integrar a América portuguesa e seus habitantes nativos à temporalidade e territorialidade cristã. Os mártires dos séculos XVI e XVII, principalmente missionários, reeditavam os martírios do início da cristandade, que espalharam o cristianismo rumo a diversas partes do mundo na antiguidade. Dessa forma, viabilizaram a cristianização das novas fronteiras, consagrando o solo com seu sangue divino e viabilizando posteriores processos de urbanização. Além da função estratégica dos mártires para os cristãos, o texto mostra que eles também tiveram significado peculiar na interlocução com as culturas ameríndias, que tinha como um de seus principais personagens o grande guerreiro, disposto a perder seu sangue em prol de seu grupo.This paper looks into a group of social agents who played a significant role in the Christianization of Portuguese America, namely, the Christian martyrs - very special individuals who were ready to wet the land with their own blood in order to make possible a definitive and irreversible occupation of the territory by Christian settlers. The martyrs, and above all the stories told about them, seem to have been called upon to integrate Portuguese America and its native inhabitants into the temporalities and territory of Christendom. Mostly made up of missionaries, this group of 16th and 17th-century martyrs reedited the martyrdom of early Christians, who spread their creed across numerous parts of the Ancient World. They enabled the Christianization of new frontiers by consecrating the soil with their divine blood and paving the way for subsequent processes of urban development. In addition to their strategic significance for Christianity, the text also shows that their martyrdom played a specific role in the Christian settlers' interaction with Amerindian culture, whose main cults included the figure of the great warrior, ever ready to shed his own blood for his group

African herbal medicines in the treatment of HIV: Hypoxis and Sutherlandia. An overview of evidence and pharmacology

In Africa, herbal medicines are often used as primary treatment for HIV/AIDS and for HIV-related problems. In general, traditional medicines are not well researched, and are poorly regulated. We review the evidence and safety concerns related to the use of two specific African herbals, which are currently recommended by the Ministry of Health in South Africa and member states for use in HIV: African Potato and Sutherlandia. We review the pharmacology, toxicology and pharmacokinetics of these herbal medicines. Despite the popularity of their use and the support of Ministries of Health and NGOs in some African countries, no clinical trials of efficacy exist, and low-level evidence of harm identifies the potential for drug interactions with antiretroviral drugs. Efforts should be made by mainstream health professionals to provide validated information to traditional healers and patients on the judicious use of herbal remedies. This may reduce harm through failed expectations, pharmacologic adverse events including possible drug/herb interactions and unnecessary added therapeutic costs. Efforts should also be directed at evaluating the possible benefits of natural products in HIV/AIDS treatment