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Objective@#To evaluate the bond performance of primers, universal adhesives and self-adhesive resin cements containing methacryloyloxydecyl dihydrogen phosphate (MDP) to zirconia.@*Methods@#Two hundred and ten yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) plates were prepared and divided into seven groups according to each of six MDP-containing products and one MDP-free resin cement. Two primers, two universal adhesives and two self-adhesive resin cements were applied on the specimens after these specimens recived alumina air abrasion. The group of MDP-free resin cement was set as control. Each group contained 30 specimens. Y-TZP plates were bonded to resin composite to build resin bonding specimens, and half of these plates were stored in distilled water at 37 ℃ for 24 hours, the other half were stored for 12 months. Shear bond strength (SBS) test and fracture modes analysis were performed.@*Results@#The SBS values of all the experimental groups were above 9.51 MPa, which increased 24-hour values compared to the (5.04±0.50) MPa of the control group. Group using one of the self-adhesive resin cement yielded the highest SBS, (11.06±0.84) MPa. SBS of all groups decreased significantly compared to 24-hour SBS after aging (P<0.05), however, the SBS values of MDP-containing products groups can still be maintained above 7.44 MPa. Two self-adhesive cement groups and one of the universal adhesive group maintained higher SBS values, and the values were statistical different from those from the two primer groups (P<0.05) .@*Conclusions@#Different MDP-containing products have different effects on the bond durability of zirconia.
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Objective:To investigate the effects of plasma treatment on the surface element,wettability and adhesion properties of aged denture base resin.Methods:42 pieces of 10 mm × 10 mm × 1 mm and 100 cubes of 8 mm × 10 mm × 30 mm polymethyl methacrylate specimens were prepared and thermocycled at 5-55 ℃ for 5 000 cycles.40 pieces were used for surface contact angle measurement and 2 for X-ray photoelectron spectroscopy analysis.The 100 cubes were randomly divided into 5 groups:Control(A) and 4 experimental groups in which the samples were exposed to plasma for 1 min (B),2 min (C),3 min (D) and 4 min (E) (n =20) respectively.After plasma treatment,silicone-based soft liner (3 mm) was packed against 2 resin cubes.Thus,50 tensile test specimens were obtained(n =10),and the tensile bond strength was tested by a universal testing machine.Results:The contact angle (°) of group A,B,C,D,E was 63.60 ± 10.81,46.79 ± 5.08,44.13 ± 4.17,40.11 ± 6.01 and 41.03 ± 8.61 respectively (A vs B,C,D or E,P ＜ 0.05).After plasma treatment,the contents of O =C-O and C-O in the samples were increased from 14.17％ and 20.58％ to 18.32％ and 29.32％,respectively.The tensile bond strength(MPa) of group A,B,C,D and E was 0.884 ±0.130,1.281 ±0.086,1.419 ±0.103,1.871 ± 0.248 and 1.904 ± 0.223 respectively (A vs B,C,D or E,P ＜ 0.05;B or C vs D or E,P ＜ 0.05;B vs C,P ＞ 0.05;D vs E,P ＞ 0.05).Conclusion:Plasma treatment can improve the wettability and adhesion properties of aged denture base resin.
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Objective:To evaluate the effect of thermocycling on nano-silver-incorporated silicone denture liner for Candida albicans (CA)adhesion.Methods:Specimens(1 0 mm ×1 0 mm ×3 mm)of silicone denture liner(control)and that incorporated with nano-sil-ver were prepared according to the manufacturer's direction.8 of the each kind of specimens were immersed in distilled water for 24 h at 37 ℃,and 8 were subjected to thermocycling for 4 000 cycles at temperatures ranging from (5 ±1 )℃to (55 ±1 )℃with a 60 s dwell time per temperature.In vitro CA adhesion assay was used to measure the levels of adherence to the specimens.Data were analysed sta-tistically.Results:Thermocycling increased CA adhesion to control specimens(P0.05 ).The adhesion of CA to nano-silver incorporated specimens was fewer than that to the controls with or wihout themocycling(P<0.01 ).Conclusion:Nano-silver incorporation may inhibit CA adhesion to silicone denture liner.Ther-mal cycling has no influence on C.albicans adhesion to silicone denture liner incorporated nano-sliver.
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16 standered acrylic resin blocks with silicone resilient denture liner(10 mm ×8 mm ×3 mm)incorporated with nano-silver par-ticles at 5% (m/m,by dry wet)in-between were prepared.8 blocks were immersed in distilled water for 24 h at 37 ℃ as the controls (group 1).Another 8 were thermocycled for 4 000 cycles(group 2).16 acrylic resin bars were thermal cycled for 4 000 cycles.Then they were processed exactly as the control group (group 3).Tensile bond strength of the specimens was measured by a universal testing machine. The bond strength values(MPa)of group 1,2 and 3 were 2.683 ±0.435,2.179 ±0.633 and 1.460 ±0.566 respectively(group 1 vs 2,P>0.05;group 3 vs 1 or 2,P<0.05).The failure mode of the blocks in group 1 and 2 was mainly cohesive failure,in group 3 adhesion fail-ure.
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ObjectiveTo investigate the predictive value of heart rate turbulence(HRT) in patients with diabetes mellitus (DM) after acute myocardial infarction (AMI).MethodsNinety-two AMI patients combined with DM (DM group) and 120 AMI patients without DM (non-DM group) were selected.Turbulence onset (TO) and turbulence slope (TS) were two indexes of HRT.HRT was considered positive when TO was ≥0 and TS was ≤2.5 ms/R-R.The differences in clinical data between HRT-positive and HRT-negative patients were compared.And the related risk factors after AMI were analyzed.ResultsAge,left ventricular ejection fraction (LVEF) level,renal insufficiency,LVEF＜40％,standard deviation of sinus cardiac cycle (R-R interval)(SDNN),heart rate variability (HRV) positiveand HRT indexes (TO,TS) between HRT-positive and HRT-negative patients in DM group had significant differences (P ＜ 0.05 ).Age,LVEF level,SDNN and HRT indexes(TO,TS) between HRT-positive and HRT-negative patients in non-DM group had significant differences(P ＜ 0.05).Multivariate Cox regression analysis showed that renal insufficiency (OR=4.8,95％ CI:1.8 - 10.7,P=0.008) and HRT positive (OR=3.7,95％ CI:1.5 - 8.6,P=0.070) in DM group had statistical significance.And HRT positive in non-DM group had statisticalsignificance(OR=23.0,95％ CI:5.2 ～ 86.0,P ＜ 0.01 ).ConclusionsHRT,an index of dynamic electrocardiogram,can predict the risk in patients with DM or without DM after AMI.
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AIM: To investigate the effect of selective silencing of SLC7a8 on uptaking L-dopa in renal tubular epithelial cells of rat (NRK-52E). METHODS: The three siRNAs targeting SLC7a8 (siRNA-1, siRNA-2, siRNA-3) were designed and synthesized. A siRNA with nonspecific coding sequence (siRNA-con) was used for control. All siRNAs were transfected into NRK-52E cells. The siRNA-con transfected group, blank control group and gene-specific silencing SLC7a8 group were set up. The efficiency of transfection was estimated by flow cytometry. The efficiency of RNA interference was detected and screened by RT-PCR preliminarily, and was followed by Western blotting at protein level. The concentrations of L-dopa uptake into the NRK-52E cells were detected by ultraviolet spectrophotometry at different time points (6, 12, 24, 36, 48, 60, 72 and 120 min). RESULTS: The transfection efficiency was 94% detected by flow cytometry. The initial screening of RT-PCR showed that the efficiencies of RNA interference of siRNA-1 and siRNA-3 were higher, and siRNA-3 was the highest at protein level determined by Western blotting. No distinctive change was found between siRNA-con treated NRK-52E and blank control cells. The L-dopa uptake at different time points (6, 12, 24, 36, 48, 60, 72 and 120min) in siRNA-interference group was lower than that in siRNA-con transfected group and blank control group. No significant difference of L-dopa uptake between siRNA-con group and blank control group was observed. CONCLUSION: RNA interference technology selectively down-regulates SLC7a8 expression in rat renal tubular epithelial cells. The L-dopa uptake is also decreased after specifically silencing the slc7a8 expression.
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AIM: To investigate the downstream genes of the transcriptional factor Pax-8 related to cardiopathy. METHODS: The total RNA derived from the heart of Pax-8 KO~(-/-) and Pax-8 KO~(+/-) mice was extracted. Mouse genome DNA microarray containing 31 802 mouse oligonucleotides probes was used to investigate the differential expression between the Pax-8 KO~(-/-) and the Pax-8 KO~(+/-) mice hearts. The candidate genes were confirmed by RT-PCR and real time RT-PCR assay. RESULTS: Microarray results showed that, compared to the Pax-8 KO~(+/-) mice, 25 genes were down-regulated and 17 were up-regulated in the Pax-8 KO~(-/-) mice, concerning metabolize enzymes, cell signal conducting and nuclear transcript factors and so on. Bcl2-like 14 (Bcl2l14) was proved to be up-regulated by RT-PCR. Real time RT-PCR results revealed that Bcl2l14 in the Pax-8 KO~(-/-) mice was 2.07 and 2.23 fold as much as that in the Pax-8 KO~(+/-) and the Pax-8KO~(+/+) mice (P<0.01). CONCLUSION: The Bcl2l14 gene is one of the downstream genes of Pax-8 and probably plays an important role in the mechanism of ventricular septum defect.
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A total of 62 disk-shaped specimens in the size of 30 mm (diameter) ×2 mm (layer thickness) were made with auto-polymerized acrylic resin (2 specimens for infrared spectrum comparison and 60 specimens for tests of water sorption and solubility). Duration of Ar plasma application was 2 minutes and plasma power applied was 60 W. Storage intervals were 1 day, 1 week, 1 month, 6 months, and 12 months, separately. A control group and a corresponding experimental group were set for each storage interval, with 6 specimens per group. All specimens were weighted 3 times, i.e., initial weight; weigh after absorption of distilled water, and final weight after desiccation. Percentages of water absorption and solubility of auto-polymefized acrylic resin were calculated. Results revealed that after Ar plasma treatment, C-H structure of auto-polymerized acrylic resin was reduced; following 1-month storage interval, water absorption percentage was significantly lower in the experimental group than in the control group; following 1-day, 1-week, and 1-month storage interval, the experimental group exhibited significantly lower solubility of auto-polymerized acrylic resin, compared to the control group (P<0.05). These results indicated that within 1-month storage, Ar plasma treatment can decrease water sorption and solubility of auto-polymerized acrylic resin.
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Objective To reveal the protective effects of atorvastatin against atherosclerosis independent of cholesterol-lowering effect, we investigated the effects of atorvastation on the expression of protein kinase C (PKC) and C-reactive protein in experimental atherosclerosis of rats.Method Fifty female Sprague-Dawley rats were randomly divided into normal diet group (n = 10, control group), vitamin D3 injection and high cholesterol diet group (n = 40). After 8 weeks, vitamin D3 injection and high cholesterol diet rats were randomized to receive either atorvastatin (5 mg. kg-1. d-1) (n = 20, atorvastatin group) or normal diet (n = 20, model group). Another eight weeks later, all rats were killed and part of their aortas were examined by light and electron microscope and the left were removed for western blot analysis to measure PKC; At the begin and end of experiment, serumcollected for lipid and C-reactive protein determining determination.Results Cholesterol, low-density lipoprotein, triglyceride levels in atorvastatin group were significantly lower than those in model group but higher than control group. The pathologic changes in atorvastatin group were less severe than those in model group, there showed no any pathological changes in control group. The levels of C-reactive protein in model group[(18.64 ± 0.94) mg/L] were higher than those in control group [(9.21 ± 0.21)mg/L] (P<0.05). C-reactive protein levels also differed significantly between control and atorvastatin group (12.52 ± 0.65 mg/L)( P<0.05). PKC levels were significantly higher in model group (7786.12 ± 264.75)and atorvastatin group (4267.57 ± 233.94) than in control group (2468.75 ± 145.53)(all P<0.05). But compared with model group, PKC levels were markedly lower in the atorvastatin group ( P<0.01 ).Conclusions Atorvastatin may be useful not only as a cholesterol-lowering agents but also as anti-arteriosclerotic agent that provide vascular protection by inhibition PKC expression and inflammatory reaction.
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AIM: Endothelial progenitor cells(EPCs) are a group of stem cells/progenitor cells,which exist in postnatal body and can be of specially homing to the foci of angiogenesis and then differentiate into endothelial cells.This investigation was to study the method for culturing endothelia progenitor cells(EPCs) in vitro,and to observe its feasibility and condition formed vessel-like structure.METHODS: The cells were isolated from born marrow,peripheral blood,umbilical cord blood or spleen in different laboratories.The EPCs derived from human umbilical cord blood and rabbit peripheral blood were cultured in vitro through adhesion selection and were differentiated into endothelial cells under the induction of special cytokines.The expression of CD34,VEGFR-2,AC133 and VE-cadherin were detected by fluorescence-activated cell sorting.The endothelial cell lineage was confirmed by DiI-ac-LDL up-taking and Ⅷ factor immunocytochemistry.RESULTS: The EPCs derived from human umbilical cord blood and rabbit peripheral blood were cultured in vitro successfully,forming cord-like and tube-like structure.The EPCs derived from rabbit peripheral blood differentiated more mature and formed vessel-like structure.CONCLUSION: The EPCs derived from human umbilical cord blood and rabbit peripheral blood formed vessel-like structure in vitro.EPCs may be a potential resource of vessel tissue engineering.
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Objective To investigate the effect of aspirin on platelet biochemical index in patients with cardio-cerebrovascular diseases and the influence of Naoxintong(Brain-heart unobstruction)Capsule.Methods The blood samples of 215 patients taking aspirin 100 mg per day for 7 days were collected for determination of platelet aggregation(PAG),P-selection level and TXB2 level by using arachidonic acid(AA)and adenosine diphosphate(ADP).Then they were divided randomly into aspirin group 1(n=72),still taking aspirin 100mg per day,aspirin group 2(n=70),taking aspirin 300mg per day,and Naoxintong group(n=73),taking aspirin 100mg per day and Naoxintong Capsule.One month later,their PAG,P-selection and TXB2 levels were re-examined.Results The plasma P-selection and TXB2 were in a positive correlation with AA-and ADP-induced PAG(P
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AIM: To investigate the function of the prot ein tyrosine kinase of focal adhesion kinase subfamily gene, the gene regulation and the signaling pathway related to ventricular septal defect during heart dev elopment. METHODS: The ALK3 downstream genes were screened usin g microarray. The ALK3 downstream genes was identified using RT-PCR and real tim e quantitative RT-PCR.RESULTS: It was found that the protein ty rosine kinase of focal adhesion kinase subfamily gene was up-regulated 3.7 fold in the 11.5 days embryonic heart of cardiac- specific deletion of ALK3 mice. CONCLUSION: The protein tyrosine kinase of focal adhesion kinase subfamily possibly is a regulatory factor in bone morphogenetic protein signalin g pathway and may be related with the development of ventricular septal defect.
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AIM: To study the effects of protein kinase C on the expression of MMPs that may play an important role in the formation of atherosclerosis and the possible mechanism of Danshen injection to treat atherosclerosis. METHODS: 50 Sprgue-Dawley (SD) rats were divided into three groups randomly: control group (group C), model group (group M) and Denshen treatment group (group D). The serum was collected to measure the level of cholesterol, triglyceride, low density lipoprotein cholesterol(LDL-ch). The expression of PKC and MMPs were measured by immunohistochemistry. Light microscope and electron microscope were also used. RESULTS: ① The cholesterol, triglyceride, LDL-ch concentrations in group M and group D were significantly higher than those in group C (P