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A comparison of techniques for assessment of coronal dye leakage.   总被引:4,自引:0,他引:4  
This study was designed to compare different techniques for coronal dye leakage testing. One hundred and fifty extracted human anterior teeth were fully instrumented and randomly divided into two experimental groups of 60 teeth each, plus two groups of 15 teeth each for positive and negative controls. One group was rinsed with 5.25% NaOCl (smear layer intact), whereas the other group was flushed with 17% EDTA and 5.25% NaOCl (smear layer removed). Roots were obturated with gutta-percha using lateral condensation and AH Plus as root canal sealer. Each experimental group was divided into three subgroups of 20 teeth each for three methods of testing coronal dye leakage: passive dye penetration, penetration with vacuum applied, and fluid filtration methods. The teeth were left in 100% humidity at 37 degrees C for 5 days before being immersed in Indian ink for 2 days and cleared. The linear extent of dye penetration was measured. Mean depth of leakage for the groups with the smear layer intact was 2.5 +/- 1.0 mm for passive dye penetration, 6.7 +/- 2.8 mm for vacuum dye penetration, and 3.0 +/- 1.1 mm for fluid filtration dye penetration. In the group in which the smear layer was removed, the mean depths of leakage were: 3.2 +/- 2.1 mm for passive dye penetration, 5.8 +/- 2.8 mm for vacuum dye penetration, and 3.4 +/- 2.1 mm for fluid filtration. The vacuum method resulted in significantly (p < 0.05) more dye penetration than fluid filtration and passive dye penetration. The presence or absence of smear layer had no statistically significant effect (p > 0.05) on any of the leakage testing techniques.  相似文献   
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An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg−1) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish). Five experimental diets were formulated by replacement of clean wheat with naturally contaminated wheat resulting in graded levels of DON and zearalenone (ZEN) (Diet 1 0.07/0.01, Diet 2 0.31/0.09, Diet 3 0.50/0.21, Diet 4 0.92/0.37 and Diet 5 1.15/0.98 mg·kg−1). Groups of 50 fish were randomly allocated into each of 20 aquaria and fed to near-satiety for eight weeks. Growth rate, feed intake and feed efficiency of fish fed the experimental diets decreased linearly with increasing levels of Fusarium mycotoxins (p < 0.05). Although growth depression was associated with feeding diets naturally contaminated with Fusarium mycotoxins, especially DON, no biochemical and histopathological parameters measured in blood and liver appeared affected by Fusarium mycotoxin concentrations of diets (p > 0.05). Though there was no clear evidence of overt DON toxicity to red tilapia, it is recommended that feed ingredients should be screened for Fusarium mycotoxin contamination to ensure optimal growth performance.  相似文献   
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Background and objective: Cholangiocarcinoma remains a serious public health concern in Thailand. While manyof the risk factors for cholangiocarcinoma in western countries are well-recognized, it remains unclear whether theyare the same in Thailand. We set out to investigate the risk factors for cholangiocarcinoma in Thailand. Methods:Starting March 4, 2016, we reviewed studies found using pre-specified keywords on SCOPUS, Pro Quest ScienceDirect, PubMed, and online public access catalog of Khon Kaen University. Two review authors independently screenedstudies for inclusion criteria, extracted data, and assessed the studied Risk of Bias. The Newcastle-Ottawa Scale and theJoanna Briggs Institute Critical Appraisal Tools were used to assess the quality of included studies. The risk effects offactors were estimated as a pooled adjusted odds ratio with a 95% confidence interval. The heterogeneity of results wasconsidered using the I-square, Tau-square and Chi-square statistics. Results: A strong association was found betweencholangiocarcinoma and age, Opisthorchis viverrini infection, eating raw cyprinoid fish, family history of cancer, liquorconsumption, and taking praziquantel. There was only a mild association found between eating nitrite-containing foods,fresh vegetables, education, smoking behavior, and sex. No association was found between cholangiocarcinoma andeating fermented fish (Pla-ra), northeastern Thai or Chinese sausage, sticky rice, meat, chewing betel nut, or eatingfruit. There were two protective factors including fresh vegetables consumption and education attainment. Conclusion:There are unique risk factors of cholangiocarcinoma in Thailand, including age, Opisthorchis  相似文献   
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Pro-inflammatory mediators produced during inflammatory response have been demonstrated to initiate and aggravate pathological development of several chronic diseases. Plant bioactive constituents have been reported to exert anti-inflammatory activities. Various parts of Moringa oleifera have long been used as habitual diets and traditional remedy along the tropical region. Anti-inflammatory activity of boiled M. oleifera pod extract was assessed by measuring pro-inflammatory mediator expression in the lipopolysaccharide-induced murine RAW264.7 macrophage cells. Prior treatment with 31–250 μg/mL M. oleifera extract for 1 h inhibited elevation of mRNA and protein level of interleukine-6, tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenease-2, induced by lipopolysaccharide for 24 h in a dose-dependent manner. The suppressive effect was mediated partly by inhibiting phosphorylation of inhibitor kappa B protein and mitogen-activated protein kinases. These results indicate that the anti-inflammatory activity from bioactive compounds present in the M. oleifera pod constituents may contribute to ameliorate the pathogenesis of inflammatory-associated chronic diseases.  相似文献   
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