OBJECTIVETo evaluate the influence of eugenol-containing and resin-containing endodontic sealers on the bond strength of fiber posts using different strategies of root canal irrigation.

METHODSForty-eight mandibular premolars were endodontically treated. The specimens were randomly assigned into two groups according to different endodontic sealers. Group A used Endofil (eugenol-containing endodontic sealer), and group B used AH-plus (resin-containing endodontic sealer). After post space preparation, each group was randomly assigned into three subgroups according to the strategies of root canal irrigation (eight premolars in each subgroup). Group Al and B1: 0.9%NaCl irrigation; Group A2 and B2: 17% ethylene diamine tetraacetic acid (EDTA)+5.25%NaClO+0.9%NaCl irrigation; Group A3 and B3: ultrasonic agitation associated with 1 7%EDTA+5.25%NaClO+0.9%NaCl. One week after the cementation of fiber posts using RelyX™ Unicem, a push-out test was performed to measure the bond strength of the posts. The microstructure of the root canal surface was examined under scanning electron microscope (SEM).

RESULTSThe bond strengths of the six groups were as follows: Al (7.96±2.23) MPa, A2 (9.95±2.89) MPa, A3 (18.88±3.69) MPa, B1 (11.41±3.71) MPa, B2 (14.00±4.04) MPa, and B3 (19.14±3.27) MPa. Statistical analysis revealed a significant interaction between the different endodontic sealers and the strategies of root canal irrigation (P<0.05). Lower bond strength was found in group Al but not in group BI (P<0.05), and the same result was revealed when comparing group A2 and B2. No significant difference was observed between group A3 and B3 (P>0.05). SEM showed that the root canal in group A3 and B3 achieved the cleanest surface with nearly all dentine tubules opened.

CONCLUSIONThe eugenol-containing endodontic sealer can impair the bond strength of fiber posts compared with the resin-containing sealer when the root canal is irrigated by 0.9% NaCl or 17%EDTA+5.25%NaClO+0.9%NaC. No difference was observed between the two sealers when using 17%EDTA+5.25% NaCIO+0.9%NaCl combined with ultrasonic irrigation.

Bicuspid ; Cementation ; Dental Bonding ; Dental Pulp Cavity ; Dental Stress Analysis ; Dentin ; Humans ; Post and Core Technique ; Root Canal Filling Materials ; Root Canal Irrigants ; Root Canal Therapy

OBJECTIVETo evaluate the effect of different auxiliary resistance forms on the resistance and marginal fitness of complete crowns for short molar preparations.

METHODSA total of 70 Nissin resin teeth were prepared with 20° total occlusal convergence, 2.5 mm of occlusocervical height, and a shallow finish line on a milling machine. The milled preparations were then randomly assigned to 7 groups of 10. The first group was used as the control group. A total of 30 dies were modified by preparing interproximal grooves with angles of 0°, 6°, and 20° centered on the mesial and distal surfaces of the dies. The rest of the teeth were prepared with occlusal holes in the center of the occlusal surface milled with the same burs to form 0°, 6°, and 20° holes. Cobalt-chromium copings were fabricated for all specimens. The marginal gap of specific points on the axial surface was measured before and after cementation. The resistance of each specimen was evaluated by applying an external force at an angle of 45° to the long axis of the die by using a universal testing machine in a lingual to buccal direction. The maximum force applied before crown dislodgement was measured. Data were analyzed using the SAS 9.2 software.

RESULTSThe results showed that the 0° groove, 0° hole, and 6° hole were effective in improving the resistance of the complete crowns (P<0.05). The 0° groove, 6° groove, 0° hole, 6° hole, and 20° hole had significant difference with the control group in terms of marginal discrepancies (P<0.05).

CONCLUSIONAuxiliary resistance forms with less degree indicate greater resistance force but worse marginal fitness. In clinical practice, if the resistance of a preparation is enough, the auxiliary resistance forms should be avoided from being used.

Cementation ; Crowns ; Dental Prosthesis Design ; Dental Prosthesis Retention ; Humans ; Molar ; Tooth Crown

Objective To construct the prokaryotic expression vector bearing fusion gene NT4-ADNF-9 and lay foundation for further study on genetic therapy of neuraseusory deafness. Methods By means of asymmetrical prince/ template, double stranded eDNA of activity dependent neurotrophic factor-9 (ADNF-9) was obtained, which included restriction enzymes sites on the two extremities. ADNF-9 eDNA was ligated to the signal and leader peptides of nenrotrophin 4 (NT4), and the fusion gene was named NT4-ADNF-9. Then it was suheluned into prokaryotic expression vector pBV220, and called pBV220/ NT4-ADNF-9. Results Evidences of DNA sequence analysis and restrtction enzymes digestion showed that we recombined ADNF-9 eDNA to the 3'terminal of the signal and leader peptides of NT4, and the fusion gene was subcluned into pBV220 successfully. Bioactivity of the products was proved that it could support the cell survival and neurite growth in the primary cultures of dorsal root ganglia (DRG) of embryonic day-8 cbicken neurons as compared to the control. Conclusion Prokaryotic expression vector pBV220/NT4-ADNF-9 can be constructed successfully and the bioactivtty is satisfactory.

Objective To prepare a kind of new lipid perfluorooctylbromide(PFOB) nanoparticles and to explore its potential application as an ultrasound contrast agent. Methods Lipid PFOB nanoparticles were prepared by microfluidization techniques. The morphology and distribution were observed with optical microscope and transmission electron microscope. Particle size and electric potential were determined with Malvern laser light scattering analyzer. Twelve normal Wistar rats were performed directly contrast imaging after injection of PFOB nanoparticles via caudal vein. Vital signs of the rats were monitored during the whole study. And eehogenie intensity of the liver was dynamically quantified through DFY ultrasound quantified analysis system. The mechanism of enhancement was studied by the frozen sections of rat's liver and spleen. Results The nanoparticles size and distribution were highly uniformed. The grey scale ultrasound imaging of the rat's liver and spleen were enhanced by PFOB nanoparticles. Ten seconds after PFOB nanoparticles injected,enhancement of liver began, the peak time was approximately 3 - 4 min, the duration of contrast enhancement was nearly up to 1 h, The enhancement of spleen was more significant and the duration was much longer. No abnormal changes of the rat's vital signs appeared during the study. Frozen sections suggested that PFOB nanoparticles accumulated in the liver and spleen was the potential mechanism of enhancement. Conclusions This novel and safe lipid PFOB nanoparticles could make prolonged enhancement of rat's liver and spleen,which has a good potency for ultrasound application.

Aim: To prepare novel aqueous polymer dispersions with high flexibility for sustained-release coating and investigate their properties. Methods: The aqueous polymer dispersions were synthesized by the emulsion polymerization. The physico-chemical properties and film-forming potential of the dispersions were investigated while the mechanical properties of the formed film and the drug release behavior when atenolol pellets were coated with the aqueous polymer dispersions were evaluated. Results: The prepared aqueous polymer dispersions (methyl methacrylate/ethyl acrylate, 1:2) were found to have proper physico-chemical properties, excellent film-forming capability and satisfying mechanical properties. It could form free film with high flexibility and low viscosity in low temperature even in absence of the plasticizer. Sustained release of atenolol pellets was achieved when the pellets were coated the polymer dispersions. 4-h and 8-h cumulative releases were more than 50% and 80%, respectively. There was no significant difference in release between pellets prior to and post compression of the coated pellets. Conclusion: The resulting aqueous polymer dispersions could be used as sustained-release coating material with high flexibility suitable for tableting.

Hypoxiaisoneofthemostimportantfactorsinfluencingcancertherapyandclinicalprogno-sis.With positron emission tomography (PET)widely adopted in clinical practice,the development and appli-cation of PET hypoxia imaging agents has been much popular in the field currently.PET hypoxia imaging can detect tumor hypoxia region noninvasively,which has important significance for optimizing cancer treatment decisions and improving the prognosis of cancer.

Objective To know the rural doctors' knowledge,belief and practice on iodine deficiency disorders(IDD),as well as their capability on health education communication in Ye County,Henan Province.Methods Semi-structured interviews were conducted among 50 rural doctors in Ye County,Henan Province.Topics covered include:sales of salt purchases,daily supervision and monitoring activities of salt,the health effects of salt,the situation of rural doctors trained,the situation of rural doctors participated in health education and related recommendations.Results ①Twenty-nine of the rural doctors knew exactly the advantage of salt iodization.②Thirty-nine of the rural doctors had taken part in the half quantitative detection of salt once or twice a year and 15 of them knew the supervision activities of salt industry department.③Forty-nine of the rural doctors believed salt iodization was beneficial to health and 48 of them were willing to participate in health education on IDD.④The major ways of their acquiring health knowledge were promotional materials [54.0％ (27/50)],TV [50.0％ (25/50)],and lecture/training [24.0％ (12/50)].⑤Thirty-seven of the rural doctors had taken part in health education on IDD.They were used to use booklets [68.0％ (34/50)],promotional slogan [36.0％ (18/50)],broadcast [24.0％ (12/50)],and doctor consultation [24.0％ (12/50)].⑥Twenty-eight of the rural doctors thought the current health education on IDD was better.They hoped to reduce the price of salt,strengthen supervision,receive more training and health education on IDD.Conclusions The rural doctors remain relatively lack of knowledge on IDD.Rural doctors have the initiative and responsibility to conduct health education on IDD,but their pattern is still a one-way propagation.

Objective To understand the fairness of health resources of endemic diseases institutions in Henan Province,to provide evidence for endemic allocation of health resources for the government.Methods Health-related data resources in endemic disease prevention and control institutions were collected in Henan Province,including personnel,business space area,the value of equipment,and health funding,etc.The percentages of population distribution and geographical distribution of health resources were calculated; Lorenz curves of demographic fairness and geographic fairness were drawn.According to Lorenz curve (Gini coefficients of the population and the geographical distribution were calculated based on Lorenz curve),Gini coefficients were used to evaluate the fairness of the endemic disease prevention institutions for health resource allocation.Results As can be seen from Lorenz curve,the population fairness of endemic disease prevention and health personnel was the best,but the number of senior officers was less and the total value of equipment owned was low.The geographical fairness of all the indicators of health resources was poorer,and geographic fairness among senior officers was the worst.The Gini coefficient of health technical personnel,senior personnel,undergraduate or above personnel,value of equipments,area of business room and health funding allocation determined by the population distribution was less than 0.4.The health resources were relatively fair and reasonable according to the distribution of population.The Gini coefficients of all the indicators determined by the distribution of geography were higher than those determined by the distribution of population.Furthermore,the geographic Gini coefficient of senior personnel was above 0.4 which was in the vigilance state.Conclusions The equality of health resources determined by population distribution in the institutions for endemic diseases control in Henan is superior to those determined by geographic distribution.The allocations of health resources of endemic diseases control in different areas are unbalanced.

Objective To explore the variation and clinical significance of growth hormone(GH) and insulin like growth factor-Ⅰ(IGF-Ⅰ) in children with critical disease.Methods One hundred and twenty-two cases were recruited into the study,among which 42 cases were sepsis in paediatric intensive care unit (sepsis group),20 cases had finished the cardiopulmonary bypass surgery without infection (surgery group).Sixty healthy children served as control group.Serum levels of GH and IGF-Ⅰ were deteced with immunochemiluminometric assay.Results The serum levels of GH were (6.71 ± 6.62) ng/ml in sepsis group,(8.86 ±8.06) ng/ml in surgery group,(3.87 ± 3.31) ng/ml in control group.Compared with the control group,the serum levels of GH in sepsis group and surgery group were increased significantly (P ＜ 0.05).There was no significant difference between sepsis group and surgery group.The serum IGF-Ⅰ levels were (63.72 ±54.17) ng/ml in sepsis group,(119.06 ± 102.12) ng/ml in surgery group and(154.22 ± 107.10) ng/ml in control group separately.The serum IGF-Ⅰ level of sepsis group was significantly decreased compared to the other two groups (P ＜ 0.05).There was no significant difference between surgery group and control group (P ＞0.05).In sepsis group,compared with those who died,the GH of the survival showed no significant difference,IGF-Ⅰ was significantly increased.(P ＜ 0.05).Conclusion GH playes a positive effect in patients with critical disease.IGF-Ⅰ decreases greatly in patients with serious infection.It suggests that IGF-Ⅰ could be a sensitive marker for reflecting whether there is serious infection.The sharply decreasing of IGF-Ⅰ may predict a bad outcome.

Objective: To investigate the expression of suppressor of cytokine signaling 2 (SOCS2) in breast carcinoma tissues and to discuss its relationship with clinical pathological data of breast carcinoma patients. Methods: The tissue microarray for 171 cases of breast carcinoma specimens, 18 adjacent tissues and 20 breast benign lesions were established. Then the expression of SOCS2, ER, PR, cerbB2, p53 and Ki-67 was detected by tissue microarray technique and S-P immunohistochemistry. Results: Positive rates of the SOCS2 protein in the breast carcinoma specimens, adjacent tissues and breast benign lesion were 57. 89% (99/171), 94. 44% (17/18), and 75% (15/20), respectively. The expression of SOCS2 was significantly different in breast carcinoma tissues of different TNM classification, different histological grades, and with or without Ki-67 expression and lymphatic metasrasis(P