987 resultados para 7038-508
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OBJECTIVE The aim of this study was to investigate the effect of different energy settings of Er:YAG laser irradiation on dentin surface morphology with respect to the number of opened dentinal tubules. BACKGROUND DATA An ideally prepared dentin surface with opened dentinal tubules is a prerequisite for adhesive fixation. No study, however, has yet compared the numbers of opened dentinal tubules with regard to statistical differences. METHODS Conventional preparations using a bur with or without additional acid etching acted as control groups. Dentin specimens were prepared from human third molars and randomly divided into eight groups according to the energy settings of the laser (1, 1.5, 4, 6, 7.5, and 8 W) and two controls (bur and bur plus acid etching). After surface preparation, dentin surfaces were analyzed with a scanning electron microscope, and the number of opened dentinal tubules in a defined area was counted. RESULTS The control groups showed smooth surfaces with (bur plus acid etching) and without opened dentinal tubules (bur), whereas all laser-irradiated surfaces showed rough surfaces. Using the energy setting of 4 W resulted in significantly more opened dentinal tubules than the conventional preparation technique using the bur with additional acid etching. In contrast, the energy setting of 8 W showed significantly fewer opened dentinal tubules, and also exhibited signs of thermal damage. CONCLUSIONS The Er:YAG laser with an energy setting of 4 W generates a dentin surface with opened dentinal tubules, a prerequisite for adhesive fixation.
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This study attempts a critical evaluation of the clinical evidence behind the use of dietary pomegranate preparations in the prevention and treatment of cardiovascular diseases. A search of PubMed on August 10, 2014 identified 228 references, which yielded extractable data from 24 clinical studies of pomegranate preparations. Hand searching identified two further studies. The quality of the studies and evidence of effectiveness of pomegranate were assessed by an established set of conventional criteria. Overall, the study quality was poor. Even in the best studies, indications of benefit did not reach the conventional levels of statistical significance. The only study with a definitive design had a biochemical rather than a clinical endpoint: it showed the expected difference in blood concentrations of myeloperoxidase after a single dose of either pomegranate or placebo. Only 10 of the 26 studies provided HPLC data on the amounts of co-active ingredients in the preparations that were consumed by the subjects. If pomegranate has a role in the prevention and treatment of cardiovascular diseases, there is a pressing need for dose-finding and long-term confirmatory studies. The ultimate endpoint for definitive studies would be mortality, but reductions in blood pressure or demonstrable decreases in atherosclerotic plaques would be useful surrogates. Sample sizes for various assumptions are provided. Future studies need to prove the clinical benefit.
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BACKGROUND Sexual transmission of Ebola virus disease (EVD) 6 months after onset of symptoms has been recently documented, and Ebola virus RNA has been detected in semen of survivors up to 9 months after onset of symptoms. As countries affected by the 2013-2015 epidemic in West Africa, by far the largest to date, are declared free of Ebola virus disease (EVD), it remains unclear what threat is posed by rare sexual transmission events that could arise from survivors. METHODOLOGY/PRINCIPAL FINDINGS We devised a compartmental mathematical model that includes sexual transmission from convalescent survivors: a SEICR (susceptible-exposed-infectious-convalescent-recovered) transmission model. We fitted the model to weekly incidence of EVD cases from the 2014-2015 epidemic in Sierra Leone. Sensitivity analyses and Monte Carlo simulations showed that a 0.1% per sex act transmission probability and a 3-month convalescent period (the two key unknown parameters of sexual transmission) create very few additional cases, but would extend the epidemic by 83 days [95% CI: 68-98 days] (p < 0.0001) on average. Strikingly, a 6-month convalescent period extended the average epidemic by 540 days (95% CI: 508-572 days), doubling the current length, despite an insignificant rise in the number of new cases generated. CONCLUSIONS/SIGNIFICANCE Our results show that reductions in the per sex act transmission probability via abstinence and condom use should reduce the number of sporadic sexual transmission events, but will not significantly reduce the epidemic size and may only minimally shorten the length of time the public health community must maintain response preparedness. While the number of infectious survivors is expected to greatly decline over the coming months, our results show that transmission events may still be expected for quite some time as each event results in a new potential cluster of non-sexual transmission. Precise measurement of the convalescent period is thus important for planning ongoing surveillance efforts.
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Repetitive DNA sequences present in the genome of Dicrocoelium dendriticum were identified by hybridization of genomic DNA that had been digested with different restriction enzymes with 32P-labeled genomic D. dendriticum DNA. DNA fragments containing repetitive sequences were isolated from PstI-digested D. dendriticum DNA and were subcloned into a plasmid vector. Plasmids containing repetitive sequences were identified by colony hybridization. One of these plasmids, designated Ddr-IV, was isolated and used as a probe in further studies. Ddr-IV is specific for D. dendriticum since it does not hybridize to DNA isolated from other trematodes. In addition, Ddr-IV was capable of detecting D. dendriticum metacercariae in ants (Formica cunicularia, F. rufibarbis, and Lasius sp.), which act as second intermediate hosts in the parasite's life cycle. Since metacercariae constitute the infectious stage of the parasite for grazing animals, Ddr-IV will provide a useful tool for epidemiology studies of dicrocoeliosis.
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iussu curatorum digessit et notis instruxit M. Steinschneider
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Edita Opera & Impensis Johannis Henrici Knebelii, Collegae Gymnasii Electoralis Joachimici
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u.a.: Übersendung von Georg Weigelt einiger Vorträge und Referate; Stellung der Philosophie; Parerga und Paralipomena; Georg Gottlieb Fichte; Religionsphilosophie; Immanuel Kant; Rezeption Schopenhauer; Georg Wilhelm Friedrich Hegel; Autobiographische Angaben von Georg Weigelt;
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[Bearb.: Ibn al-Muqaffa]. Nunc primum Graece ex mss. cod. Holsteiniano prodit, cum versione nova Latina, opera Sebast. Gottofr. Starkii. Aus dem Arab. ins Griech. übers. von Simeon
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Although long distance running clearly has benefits--as witnessed by its popularity--it also has risks of injury and death. Little is known, however, about the prevalence of potentially dangerous training habits in long distance runners, although anecdotal information suggests that many runners have erroneous beliefs about risks and benefits of marathon running. We conducted a cross-sectional survey to estimate the prevalence of 19 potentially dangerous training habits (risky behaviors) among marathon runners. A 66-item self-administered questionnaire was mailed to a stratified random sample of runners who finished of the 1992 Houston-Tenneco Marathon and were 21-71 years of age. Responses were obtained from 508 runners (83%) with approximately equal representation in four age-gender groups: men $<$40 years, men $\ge$40 years, women $<$40 years, and women $\ge$40 years.^ Prevalences of risky behaviors were high. 50% or more ran in dangerously hot and humid conditions, did not cool down or stretch after running, did not wear proper running gear, or ran when injured or ill; 25-49% did not warm up, ran on dangerous surfaces, did not drink sufficient water during training, increased weekly mileage too quickly, and ran during lightning storms; 10-24% ran daily, ran in areas with high pollution, ran in the same direction as traffic, did hard runs frequently, ran more than 60 miles per week, or ran against the advice of a physician.^ Positive associations were found between the practice of risky behaviors and self-reported prevalence of musculoskeletal injuries, heat-related injuries, noncompliance with recommendations for preventive health examinations, and noncompliance with positive health habits.^ These results indicate that many marathon runners engage in training habits that may increase risk of substantial injury or illness. Further studies are needed to explore the association of risky training behaviors on the incidence of injuries, and to determine reasons for noncompliance with recommendations from sports medicine specialists. ^