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排序方式: 共有290条查询结果,搜索用时 31 毫秒
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Farhad Tabatabaian Alireza Jafari Mahshid Namdari Minoo Mahshid 《The Journal of prosthetic dentistry》2019,121(2):327-332
Statement of problem
The effects of coping and veneer thickness on the color of zirconia-based restorations are unknown.Purpose
The purpose of this in vitro study was to evaluate the influence of coping and veneer thickness on the color of zirconia-based restorations on different implant abutment backgrounds and to define minimum coping and veneer thicknesses for the backgrounds investigated to achieve a target color.Material and methods
Thirty zirconia disk specimens with thicknesses of 0.4, 0.6, and 0.8 mm and 30 veneering ceramic disk specimens with thicknesses of 0.8, 1.0, and 1.2 mm were fabricated. Three backgrounds were prepared: titanium alloy, zirconia ceramic, and base metal alloy. The zirconia specimens were placed on the backgrounds, and the veneering ceramic specimens were located on the zirconia specimens. Spectrophotometric measurements were made to determine CIELab values. Color difference (ΔE) values were calculated to measure color differences between the specimens and the A2 VITA classical shade tab. ΔE values were compared with a perceptibility threshold (ΔE=2.6). Repeated measures ANOVA, Bonferroni test, and 1-sample t test were used to analyze data (α=.05).Results
Mean ΔE values ranged from 2.0 to 9.8. Coping thickness, veneer thickness, and their combination significantly affected ΔE (P<.001).Conclusions
To achieve the target color with zirconia-based restorations, regardless of the backgrounds tested, the minimum thickness of zirconia coping should be 0.6 mm, and the minimum thickness of veneering ceramic should be 1.2 mm. 相似文献3.
Elahi E Khodadad A Kupershmidt I Ghasemi F Alinasab B Naghizadeh R Eason RG Amini M Esmaili M Esmaeili Dooki MR Sanati MH Davis RW Ronaghi M Thorstenson YR 《The Journal of molecular diagnostics : JMD》2006,8(1):119-127
This is the first comprehensive profile of cystic fibrosis transmembrane conductance regulator (CFTR) mutations and their corresponding haplotypes in the Iranian population. All of the 27 CFTR exons of 60 unrelated Iranian CF patients were sequenced to identify disease-causing mutations. Eleven core haplotypes of CFTR were identified by genotyping six high-frequency simple nucleotide polymorphisms. The carrier frequency of 2.5 in 100 (1 in 40) was estimated from the frequency of heterozygous patients and suggests that contrary to popular belief, cystic fibrosis may be a common, under-diagnosed disease in Iran. A heterogeneous mutation spectrum was observed at the CFTR locus in 60 cystic fibrosis (CF) patients from Iran. Twenty putative disease-causing mutations were identified on 64 (53%) of the 120 chromosomes. The five most common Iranian mutations together represented 37% of the expected mutated alleles. The most frequent mutation, DeltaF508 (p.F508del), represented only 16% of the expected mutated alleles. The next most frequent mutations were c.1677del2 (p.515fs) at 7.5%, c.4041C>G (p.N1303K) at 5.6%, c.2183AA>G (p.684fs) at 5%, and c.3661A>T (p.K1177X) at 2.5%. Three of the five most frequent Iranian mutations are not included in a commonly used panel of CF mutations, underscoring the importance of identifying geographic-specific mutations in this population. 相似文献
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Erythropoietin attenuates motor impairments induced by bilateral renal ischemia/reperfusion in rats 下载免费PDF全文
Mahshid Tahamtan Seyed M.S. Moosavi Vahid Sheibani Mohsen Nayebpour Saeed Esmaeili‐Mahani Mohammad Shabani 《Fundamental & clinical pharmacology》2016,30(6):502-510
Neurologic sequelae remain a common and destructive problem in patients with acute kidney injury. The objective of this study was to evaluate the possible neuroprotective effect of erythropoietin (EPO) on motor impairments following bilateral renal ischemia (BRI) in two time points after reperfusion: short term (24 h) and long term (1 week). Male Wistar rats underwent BRI or sham surgery. EPO or saline administration was performed 30 min before surgery (1000 U/kg, i.p.). Explorative behaviors and motor function of the rats were evaluated by open field, rotarod, and wire grip tests. Plasma concentrations of blood urea nitrogen (BUN) and creatinine (Cr) were significantly enhanced in BRI rats 24 h after reperfusion. BRI group had only an increased level of BUN but not Cr 1 week after reperfusion. Impairment of balance function by BRI was not reversed by EPO 24 h after reperfusion, but counteracted 7 days after renal ischemia. Muscle strength had no significant differences between the groups. BRI group had a decrease in locomotor activity, and EPO could not reverse this reduction in both time points of the experiment. Although EPO could not be offered as a potential neuroprotective agent in the treatment of motor dysfunctions induced by BRI, it could be effective against balance dysfunction 1 week after renal ischemia. 相似文献
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Effect of soluble copper released from copper oxide nanoparticles solubilisation on growth and photosynthetic processes of Lemna gibba L 总被引:1,自引:0,他引:1
Copper oxide nanoparticles (CuO NPs) are used as a biocide in paints, textiles and plastics. Their application may lead to the contamination of aquatic ecosystems, where potential environmental effects remain to be determined. Toxic effects may be related to interactions of NPs with cellular systems or to particles' solubilisation releasing metal ions. In this report, we evaluated CuO NPs and soluble copper effects on photosynthesis of the aquatic macrophyte Lemna gibba L to determine the role of particle solubility in NPs toxicity. When L. gibba plants were exposed 48 h to CuO NPs or soluble copper, inhibition of photosynthetic activity was found, indicated by the inactivation of Photosystem II reaction centers, a decrease in electron transport and an increase of thermal energy dissipation. Toxicity of CuO NPs was mainly driven by copper ions released from particles. However, the bioaccumulation of CuO NPs in plant was shown, indicating the need to evaluate organisms of higher trophic level. 相似文献
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Cardioprotective effect of N, α-L-rhamnopyranosyl vincosamide (VR), isolated from the leaves of Moringa oleifera plant in doxorubicin (Dox)-induced cardiac toxicity rats was evaluated. Twelve (12) rats were randomly selected into three groups; two rats received distilled water in the control group, five rats in group I received varying concentration of VR treatment, and group II containing five rats received varying concentration of VR-loaded magnetic hydrogel nanocomposite. Malondialdehyde (MDA), glutathione peroxidase (GSH) and superoxide dismutase (SOD) enzymes activities level were analysed after two weeks. In addition, the expression of three heart failure markers; beta major histocompatibility complex (β-MHC), atrial natriuretic peptide (ANP), and B type natriuretic peptide (BNP) were also evaluated. It was observed that the level of these markers expression decreases with an increase in VR concentration (p?0.05). The reduced GSH and SOD level were increased after VR administration, this extract also reduced the initially increased MDA level in cardiac tissue. Pharmacokinetic parameters evaluation showed that nanogel treated rats possesses a significantly increased VR plasma concentration, Cmax, Kel, t½(a), t½(el), Ka and AUC. The result of this study indicated that VR may help to lower the dosage level, and reduces the treatment course in cardiovascular diseases (CVD). Our conclusion proposes the cardio-protective ability of the isolated VR and its beneficial effect via free radical scavenging properties. 相似文献
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