120 extracted maxillary first premolars were endodontically treated and randomly divided into 5 groups(n=24).The teeth in group A had 4 walls of coronal tooth structure,in group B,C,D and E had only 3 walls,missing the palatal,buccal,mesial and distal wall,respectively.The teeth in group A0-E0(n=6)were restored without post,in group A1-E1(n=6)with buccal post,in group A2-E2(n=6)with palatal post,in group A3-E3(n=6)with buccal and palatal post,respectively.The fracture resistance of group A was higher than that of B,C,D and E groups(P＜0.05).The fracture resistance of fiber posts placed in the buccal root canal was higher than that in the palatal root canal(P＜0.05).The 360° complete ferrule can provide the best fracture resistance,When the ferrule is not complete,it is recommended to place buccal fiber post for repair.

Objective:To establish a standard method to evaluate the scanning accuracy of intraoral scanner (IOS) and to investigate six IOS′s scanning accuracy and the relationship between different scan span.Methods:Five simplified six abutments full arch model were fabricated by high accuracy (5 μm) milling machine with 7075 aluminum alloy. The machining accuracy, which was verified by a coordinate measuring machine with higher accuracy (0.7 μm), was considered as the reference accuracy. The model with the highest machining accuracy was considered as the test model in IOS′s scanning accuracy test, and computer-aided design (CAD) data of the model was used as the reference data. Six IOS scanned the test model 10 times with the same scanning path, obtained 60 test data. CAD data and test data were input into Geomagic Studio 2014. The preparation part above the margin of the abutments of the data was isolated and divided into 4 segments of interest: single crown, three-unit bridge, five-unit bridge, and full arch. The test data were then best-fit aligned to CAD data or each other followed by deviation analysis. Scanning trueness and precision were then calculated.Results:The mid-value of scanning trueness and precision of six IOS in single crown, three-unit bridge, five-unit bridge and full arch were 13.3-29.6 μm and 7.6-20.7 μm, 15.4-30.9 μm and 8.7-26.5 μm, 17.0-66.1 μm and 11.3-44.2 μm, 24.0-107.9 μm and 24.6-150.1 μm respectively.Conclusions:Long-span scanning can affect the accuracy of IOS to a varying extent.

Objective:To observe the changes of rapidly activated delayed rectifier potassium channel (IKs) and slowly activated delayed rectifier potassium channel (IKs) in cardiac hypertrophy and to evaluate the effects of IKs and IKs blocker on the incidence ofventricular arrhythmias in guinea pigs with left ventricular hypertrophy (LVH).Methods:Guinea pigs were divided into a sham operation group and a left ventricular hypertrophy (LVH) group.LVH model was prepared.Whole cell patch-clamp technique was used to record IKr and IKs tail currents in a guinea pig model with LVH.The changes of QTc and the incidence rate of ventricular arrhythmias in LVH guinea pigs were observed by using the IKr and IKs blockers.Results:Compared with cardiac cells in the control group,the interventricular septal thickness at end systole (IVSs),left ventricular posterior wall thickness at end systole (LVPWs),QTc interval and cell capacitance in guinea pigs with LVH were significantly increased (P＜0.05);while IKs densities were significantly reduced [+60 mV:(0.36±0.03) pA/pF vs (0.58±0.05) pA/pF,P＜0.01].However,LVH exerted no significant effect on IKr densities.IKr blocker markedly prolonged the QTc interval (P＜0.01) and increased the incidence of ventricular arrhythmias in guinea pigs with LVH compared with the control guinea pigs.In contrast,IKs blocker produced modest increase in QTc interval in guinea pigs of control group with no increase in LVH animals.IKs blocker did not induce ventricular arrhythmias incidence in either control or LVH animals.Conclusion:The cardiac hypertrophy-induced arrhythmogenesis is due to the down-regulation of IKs.

Objective: To observe the dynamic changes of plasma level thymosinβ4 (Tβ4) in acute myocardial infarction (AMI) patients with intervening therapy within 15 days of onset and to explore the relationship between Tβ4 and clinical prognosis in AMI patients.
Methods: Our research included 2 groups:AMI group, n=69 and Control group, the patients with suspected chest pain while CAG excluded coronary artery stenosis, n=32. Plasma levels of Tβ4 were examined in all AMI patients on admission day and every day until 15 days of onset;AMI patients were followed-up for 18 months and the endpoint was defined as major adverse cardiovascular event (MACE) occurrence.
Results: ①Compared with Control group, AMI group had increased plasma level of Tβ4 on admission day and on day-15 of onset, P<0.01. ② With intervening therapy, AMI group had elevated Tβ4 level upon immediate onset, it was decreased on day-1, reached low level on day-3 and elevated to peak on day-6, then reduced followed by slightly raising on day-11.③During follow-up period, the AMI patients without MACE had the higher mean in-hospital maximum Tβ4 value than those with MACE occurrence, P<0.01. Logistic regression analysis indicated that the mean in-hospital maximum Tβ4 value was related to MACE occurrence during follow-up period (OR=0.999, 95%CI 0.999-1.000).
Conclusion: AMI may induce up-regulated expression of plasma Tβ4;with intervening therapy, Tβ4 showed a trend of“elevation-reduction-elevation-reduction”at the early stage of AMI. High expression of Tβ4 was helpful for improving clinical prognosis in AMI patients which may provide a theoretical basis for exogenous use of Tβ4 in AMI treatment.

[ Abstrct] Back in the 1980s, β?blockers was widely used because of decreased myocardial infarction mortality and protected heart function. In recent years, with the rapid development of percutaneous coronary intervention ( PCI) technology, the mortality of pa?tients with acute myocardial infarction ( AMI) significantly decreased. The issue of whether patients with AMI continue to benefit fromβ?blockers treatment is disputed. This review is aim to retrospect the researches about the effects ofβ?blockers on patients with AMI in aspects of myocardial infarct size, heart failure and mortality after AMI, meanwhile summarizing the rational use ofβ?blocker therapy in the PCI era.

Objective To evaluate the effect of tirofiban injection in coronary artery occlusion by suction catheter on the opening time of the coronary artery occlusion , the improvement of the blood flow and the incidence of adverse events in 30 days. Methods A total of 97 patients with acute myocardial infarction in recent 4 years were included , whose culprit vessels were subtotal occlusion or total occlusion by angiography and were randomly divided into thrombus aspiration group (group A) and tirofiban injection in occlusion and thrombus aspiration group (group B). The opening time of the coronary artery, the improvement of the blood flow and the incidence of adverse events in 30 days were compared between two groups. Results The opening time of the coronary artery occlusion in group A was shortened when compared with group B but the blood flow arriving TIMI III grade in group B was shorter (P < 0.05). No-reflow incidence in group B was lower while the proportion of blood flow arriving TIMI III grade was higher than that in group A in early phase (P < 0.05). The incidence of adverse events in 30 days was decreased in group B when compared with group A ,but the difference wasn't statistically significant (P > 0.05). Conclusion Direct tirofiban injection in coronary artery occlusion could effectively shorten the opening time of the coronary artery occlusion reduce no-reflow incidence , and improve coronary perfusion but could not decrease the incidence of adverse cardiovascular events in 30 days.

Objective To study the effects of internal exposure of 18F-FDG (18F-2-deoxy-2-fiuoroD-glucose) on the protein expressions of P53,XIAP (X-linked inhibitors of apoptosis protein) and GADD (growth arrest and DNA damage)45 in Lewis lung carcinoma,and to explore the possibility of applying 18F-FDG as a radiotherapy drug in vivo.Methods Lewis lung cancer transplanted tumor models were established via subcutaneous injection of 0.2 ml of 2 × 107/ml Lewis lung carcinoma cells at left hind limbs of 48 C57BL/6 mice that were randomly divided into high dose group,low dose group and control group with 16 mice each.After 7 d of cancer cell inoculation,18.5 × 107 Bq and 9.25 × 107 Bq of 18F-FDG in 0.2 ml saline or equal volume of physiological saline was intraperitoneally injected into three group mice,respectively.22 d post inoculation,the protein expressions of P53,XIAP and GADD45 were immuohistochemically detected by using SP approach.Results There was significant difference among the protein expressions in each group (x2 =8.30,16.02,7.68,P ＜0.05).The mean integral optic density of protein expression increased from 0.089 ± 0.033 in control group to 0.315 ± 0.028 in high dose group for P53,and from 0.126 ± 0.023 to 0.383 ±-0.035 for GADD45,but it decreased from 0.422 ± 0.034 to 0.149 ± 0.055 for XIAP.There was significantly difference of these protein expressions in each group (P53:F=5.26,P＜0.05;XIAP:F=4.29,P ＜0.05;GADD45:F=5.98,P ＜0.05).Conclusions 18F-FDG can up-regulate the expressions of P53 and GADD45 proteins and down-regulate the expression of XIAP protein in tumor cells,and it inhibits tumor growth by promoting cell apoptosis in the Lewis lung carcinoma tissue with a P53-dependent manner.

Objective: To analyze influencing factors of percutaneous coronary intervention (PCI) on therapeutic effect in patients with coronary chronic total occlusions (CTO). Methods: Clinical data, lesion features and PCI therapeutic results of 65 patients with 72 CTO lesions, who received PCI in our hospital from Jan 2010 to Dec 2012, were retrospectively analyzed. Results: PCI success rate of CTO lesion was 91.67% (66/72); compared with patients with CTO occlusion 3~12 months, there was significant decrease in PCI success rate (97.78% vs. 81.48%) in those with CTO occlusion >12 months; compared with patients with occlusion length ≤15mm, there was significant decrease in PCI success rate (97.96% vs. 78.26%) in those with occlusion length >15mm; compared with patients with mouse tail-like broken ends, there was significant decrease in PCI success rate (96.55% vs. 71.43%) in those with knife cut-like broken ends, P<0.05 all; PCI failed in six lesions, in which four because guidewire failed to pass through lesions and two because balloon failed to pass through lesions; incidence rate of complications was 7.69% during PCI, there were no major adverse cardiovascular events during admission in all patients; symptoms relieving rate of angina pectoris was 90.16% after PCI. Conclusion: Success rate of percutaneous coronary intervention is related to lesion features, CTO occlusion duration etc.

Aim To investigate the effects of β1-ad-renergic receptor (β1-AR ) on rapid component of the delayed rectifier potassium current ( IKr ) in ventricular
myocytes of guinea pigs with chronic heart failure ( CHF) . Methods The CHF model of guinea pigs was established by descending thoracic aortic banding .
Whole-cell patch-clamp technique was used to record IKr in ventricular myocytes. The effects ofβ1-AR on IKr in CHF ventricular myocytes were detected and its mechanisms were studied by pretreatment with protein kinase A ( PKA ) inhibitor and calmodulin kinase II( CaMK II) inhibitor. Results In CHF ventricular myocytes, xamoterol, the selectiveβ1-AR agonist, de-creased IKr by (52±8)% and prolonged action poten-tial duration. These effects were completely abolished by pretreatment of myocytes with CGP20712A, a selec-tive β1-AR antagonist. íamoterol only decreased IKr
by (28±3)% by pretreatment of CHF myocytes with specific PKA inhibitor KT5720 . KN93 , an inhibitor of CaMKII, did not attenuate the inhibitory effect on CHF ventricular myocytes. Conclusion IKr is inhibi-ted by β1-AR activation in CHF ventricular myocytes. PKA, but not CaMKII signaling pathway is involved in, at least in part, the inhibitory effect ofβ1-AR acti-vation on IKr.