BACKGROUND:Studies have confirmed that the surface treatment methods such as silane coupling agent and sand blasting could improve bonding strength of zirconia ceramics and resin binder. In addition, the increase of micro cracks on the surface of zirconia ceramics can also improve the bonding strength of zirconia ceramics and resin binder. But there is a lack of related studies addressing whether repeatedly sintering would have an impact on shear bond strength of zirconia ceramics.
OBJECTIVE:To determine the effect of decorative porcelain temperature firing on the shear bond strength between dental zirconia ceramics and resin binder.
METHODS:Twenty pieces of zirconia ceramics specimens were selected from 40 tablets, and then randomly divided into five groups according to the number of sintered times:control group (without sintering), sintering groups for 2, 4, 6, 8 times. Heat starting temperature was 500 ℃, and final temperature was 1 000 ℃ with a heating rate of 55 ℃/min. The vacuum time was 7 minutes. During the sintering, the final temperature was constant. Unsintered ceramic pieces were bonded using resin binder. Universal testing machine was used to test the shear strength of the interface between the two pieces of zirconia ceramics. The interface after shearing was characterized by scanning electron microscope.
RESULTS AND CONCLUSION:The shear strength of sintering groups for 4, 6, 8 times was significantly higher than that of the control group (P<0.05). Shear strength of specimens sintered twice was slightly higher than that of specimens without sintering, but the difference was not significant (P>0.05). Shear strength of specimens sintered 8 times was slightly higher than that sintered 4 and 6 times (P<0.05). Under the scanning electron microscope, there was no crack on the surface of non-sintered zirconia ceramics. After 2 times sintering, the surface appeared to have fine cracks. After sintering 4 times, visible cracks were increased. After six rounds of sintering, the surface began to have significant changes;cracks rose along with slight gaps and a smal amount of adhesive residues were found. After sintering for 8 times, cracks and voids were obviously increased on the sintered surface and adhesive residues were found. It indicated that after sintering for 4, 6 and 8 times, zirconia ceramics could have a good shear strength binding to resin adhesives;with the increasing of sintering times, the shear bond strength could be increased.

According to the investigation result in 398 students of the College of Pharmacy of Chongqing Medical University on study motivation,atitude,extracurricular study time and study method,the entire status of study attitude in pharmacutical students and the effect of study motivation,attitude,grade diversity and gender difference on learning were analyzed.It is indicated that the pharmacutical students in medical university are a group with a certain speciality.Therefore,in order to improve the educational quality of pharmacy,the teaching and students affairs should be developed with clear target.

Objective The relationship was analyzed between clinic and the expression intensity of HBsAg and HBcAg with in the hepatic tissue from the serum HBeAg negative group and the positive group.Methods A total of 317 liver biopsy specimens were divided into the HBeAg negative group and the positive group,and the relationship was analyzed between the expression inten sity of HBsAg and HBcAg within the hepatic tissue and their age,gender,ALT level,serum HBV-DNA load,hepatic inflammatory activity grading and fibrosis staging in the two groups.Results Age,ALT level,hepatic inflammatory activity grading and fibrosis of the serum HBeAg negative patients were greater than those of the serum HBeAg positive patients,while their serum HBV-DNA load and the expression intensity of HBcAg within the hepatic tissue were lower than those of the serum HBeAg positive patients (P＜0.05).The expression intensity of HBsAg within the hepatic tissue between the serum HBeAg patients and the serum HBeAg positive patients was not significantly different,and it was not correlated with age,ALT level,hepatic inflammatory grading and fi brosis staging (P＞0.05).After the serum HBeAg turned negative,the expression intensity of HBcAg within the hepatic tissue was decreased (P=0.00,t=12 349.0),and it became positively correlated with the serum HBV DNA load(P=0.007,r=0.251) and its negative correlation with the hepatic inflammatory activity and fibrosis was weakened.Conclusion After the serum HBeAg turned negative,other antigenic components of HBV may still maintain the adequately active immune status within the hepatic tis sue of organisms.After the serum HBeAg turned negative,the expression intensity of HBcAg within the hepatic tissue was de creased and became positively correlated with the serum HBV DNA,while its negative correlation with the hepatic inflammatory activity grade and fibrosis stagings was weakened.

BACKGROUND:At present, there are stil differences in the studies of total-etch, self-etch and self-bonding resin cement effect on the coronal microleakage and bonding strength of fiber posts.
OBJECTIVE:To evaluate the coronal microleakage and the bonding strength of fiber posts treated with three kinds of resin cements.
METHODS:Total y 32 upper incisors were randomly divided into five groups, including three experimental groups and two control groups. After the root canal preparation, three kinds of resin cements (EMBRACE WetBond, LuxaCore, Medental Multi-cure) were used to fiber posts with the bond diameter of 1.4 mm. Stereomicroscope was used to observe the microleakage. Then, the specimens were cut into 2 mm wafer along the axis of tooth, and universal testing machine for push-out test was used to observe the failure mode. In the positive control group, no root canal preparation was done, the root was coated with nail polish, and the crown was directly exposed to the dye. In the negative control group, no root canal preparation was done, the root canal orifice was covered with the resin, the tooth was overal coated with nail polish and then embedded 1 mm below the section.
RESULTS AND CONCLUSION:The microleakage was observed in al the three resin cements, Medental Multi-cure showed the least microleakage and LuxaCore showed the largest microleakage, and there was significantly different among the three kinds of resin cements (P<0.05). The bonding strength of three cements had significant differences (P<0.05), and ranked from high to low:Mdental Multi-cure, LuxaCore, and EMBRACE WetBond. The main fracture modes were binder/fiber post fracture and mixed failure. The results suggest that the total-etch resin cement binds tightly with the dentin, and owns a superiority in the microleakage and bonding property as compared with the self-etch resin cements and self-bonding resin cements.

BACKGROUND:Microleakage between restoration, tooth structure and bonding agent can cause the entry of bacteria and liquid in the mouth into the gap, thereby damaging the bonding interface between the restoration and tooth tissues, and leading to bond failure. Microleakage detection can directly show whether the closure of the root canal of post and core system is good or bad. The severity of microleakage directly affects the restorative effects of post and core. OBJECTIVE: To evaluate the effects of different root canal cleaning methods on the microleakage between the fiber post and root canal dentin. METHODS: Thirty fresh non-caries premolar posts with free root canalin vitro were randomly divided into five groups, and the root canal wal was respectively washed with saline, 5.25% sodium hypochlorite solution+17% ethylenediamine tetra-acetic acid (EDTA)+saline, 3% hydrogen peroxide solution+5.25% sodium hypochlorite+ saline, 3% hydrogen peroxide solution+2% chlorhexidine solution+saline, and 2% chlorhexidine solution+17% EDTA+saline in different groups. Super-bond C&B adhesive agent was used for bonding fiber post, and the microleakage of each sample was observed under stereomicroscope. RESULTS AND CONCLUSION: The severity of microleakage in the al groups was ranged as folows: saline group > 3% hydrogen peroxide solution+5.25% sodium hypochlorite+saline group > 5.25% sodium hypochlorite solution+17% EDTA+saline and 3% hydrogen peroxide solution+2% chlorhexidine solution+saline groups > 2% chlorhexidine solution+17% EDTA+saline group.

Objective To introduce inhaled inactivated-mycobacterium phlei on prevention and treatment of moderate bronchial asthma to observe the clinical effect. Method This study was a prospective and controlled study. The patients diagnosed with asthma in our out-patient from March 2009 to December 2010 were collected, who met the following conditions were included in the study: age≥ 14 years; met the criteria of moderate chronic persistent bronchial asthma in Global Initiative for Asthma (GINA) in 2008; suspended receiving systemic corticosteroids, Montelukast, ketotifen and other anti-inflammatory and anti-allergic drugs in one month; no significant respiratory tract infections; and other serious illnesses or abnormalities known.A total of 100 patients with asthma were selected, including 37 males and 63 females, age (32.11 ± 12.95 )years. The patients were randomly(random number) divided into two groups: A group(treatment group; 16males and 34 females, age 33.56 ± 14.23 years) and B group (control group; 21 males and 29 females,age 30.66 ± 11.50 years); 50 in each group. No significant difference was noted between the two groups on age and gender composition. The patients in A group were treated with inhaled inactivated-mycobacterium phlei F. U. 36 Injection 1.72 μg/mL × 2 that adding 3 mL normal saline, once a day for 5 days. The patients in B group were treated with salmeterol xinafoate and fluticasone propionate powder for inhalation (50/100 μg), twice daily for sustainable use. The patients in the two groups were observed for one month. During this course, the patients in the two groups could inhale the salbutamol sulphate aerosol as need to relieve symptoms. And the number of using was recorded. Pulmonary function test and asthma provocative test were carried out on the Day O, 6 and 31. ACT scores were measured before and after the treatment. Results On Day 6 and 31 after treatment, the negative conversion rates of asthma provocative test of the patients in A group were 82% and 78% respectively, B group were 84% and 90% respectively. Provocative test of the patients in the two groups were negative conversion significantly before and after treatment. There was no significant difference between the two groups by chi-square test (P ＞ 0. 05 ). Completely random designed data was analyzed by analysis of variance. The analysis showed that the accumulated doses of methacholine of the patients in the two group increased significantly ( P ＜ 0. 05 ), but no difference between the two groups.There was a improvement trend on forced expiratory volume in one second( FEV1 )of the patients in A group after treatment, but no difference. FEV1 of the patients in B group increased significantly higher ( P ＜0.05), which was significantly higher than A group on the 31th day (P ＜0. 05); Peak expiratory flow (PEF) of the patients in the two group increased significantly on Day 6 and 31 after treatment (P ＜0.05 ).On Day 31, B group was significantly higher than A group ( P ＜ 0. 05 ); Scores of asthma control test (ACT)of the patients in the two group were significantly increased, and the number of using of salbutamol sulfate aerosol was significantly reduced (P ＜0.01 ). B group was obvious than group A (P ＜0.05 ). During treatment, there were only two adverse reaction cases of transient low fever; most obvious was on the third day.Conclusions Inhaled inactivated-mycobacterium phlei would inhibit the airway hyperresponsiveness of the patients with moderate bronchial asthma in short time, improve the symptoms, reduce the acute exacerbation, and reduce the use of rescue medication, which has the roles of prevention and treatment of moderate asthma in a certain period of time.

BACKGROUND:Due to limitations of the physicochemical properties of soft denture liner material itself, whisker has been added in the soft lining material in recent years, so as to enhance its mechanical properties. OBJECTIVE:To investigate the effect of different additive amount of anhydrous calcium sulfate whisker on the mechanical function of self-curing soft denture liner. METHODS: There were six groups in this experiment. Anhydrous calcium sulfate whisker at the mass fraction of 0 (control), 1%, 2%, 3%, 4%, 5% was respectively added into self-curing soft liner materials, 10 test specimens in each group, a total of 60 test specimens. The shear bond strength, Shore hardness and tensile strength were detected. RESULTS AND CONCLUSION: With the increasing amount of the anhydrous calcium sulfate whisker, the Shore hardness of the soft lining material was increased continuously, and the tensile strength was increased firstly and then reduced. When 3% anhydrous calcium sulfate whisker was added, the bond strength and tensile strength of soft lining material reached the peak. Taken together, the mechanical properties of the soft lining materials became perfect when 3% anhydrous calcium sulfate whisker was added. These results demonstrate that anhydrous calcium sulfate whisker may affect the mechanical properties of self-curing soft liner.

OBJECTIVE: To explore the genetic basis for a pedigree affected with X-linked mental retardation. METHODS: The proband was subjected to chromosomal karyotyping, FMR1 mutation testing and copy number variation analysis with a single nucleotide polymorphism microarray (SNP array). His family members were subjected to multiplex ligation-dependent probe amplification (MLPA) assaying. Expression of genes within the repeated region were analyzed. RESULTS: The proband had a normal chromosomal karyotype and normal number of CGG repeats within the FMR1 gene. SNP array identified a 370 kb duplication in Xq28 (ChrX: 153 027 633-153 398 515), which encompassed 14 genes including MECP2. The patient was diagnosed as Lubs X-linked mental retardation syndrome (MRXSL). MLPA confirmed the presence of copy number variation, its co-segregation with the disease, in addition with the carrier status of females. Genes from the duplicated region showed higher levels of expression (1.79 to 5.38 folds) within peripheral blood nucleated cells of the proband. CONCLUSION The patients were diagnosed with MRXSL. The expression of affected genes was up-regulated due to the duplication. Genetic counseling and prenatal diagnosis may be provided based on the results.
DNA Copy Number Variations ; Female ; Fragile X Mental Retardation Protein ; Humans ; Mental Retardation, X-Linked ; Methyl-CpG-Binding Protein 2 ; Pedigree ; Pregnancy

Objective:To investigate the effects of hyperuricemia on the prognosis of IgA nephropathy (IgAN) using propensity score matching (PSM) method.Methods:IgAN patients proven by biopsy were included. PSM was used to match patients. Kaplan-Meier method was used for survival analysis, and Cox regression analysis was used to analyze the effects of hyperuricemia on IgAN prognosis. Primary outcome events were defined as death, or end-stage renal disease (dialysis, transplantation), or a decrease in estimated glomerular filtration rate (eGFR) greater than 40%. Renal outcome was defined as end-stage renal disease (dialysis, transplantation), or a decrease in eGFR greater than 40%.Results:A total of 1 454 IgAN patients were included in this study, including 850 females and 604 males. Uric acid level was (368.26±92.87) μmol/L in the males, and (277.23±92.71) μmol/L in the females. The median follow-up time was 85.00(56.10, 106.33) months. During the follow-up period, a total of 134 patients reached the primary outcome events, including 5 deaths, 24 dialysis patients, 5 kidney transplant patients, and 100 patients with eGFR decreased by more than 40%. After 1∶1 matching, 131 males and 159 females in the hyperuricemia group were successfully matched with 131 males and 159 females in the normal uric acid group, and there was no significant statistical difference in each parameter in baseline between the hyperuricemia group and normal uric acid group after matching. Kaplan-Meier survival analysis showed that either before or after matching, the incidence of primary outcome events in male or female patients with hyperuricemia was higher than those with normal uric acid, but there was no statistically significant difference in incidence of primary outcome events between female hyperuricemia group and female normal uric acid group after matching (Log-rank test, χ2=3.586, P=0.058). Cox proportional hazard regression model showed that, in the pre-match fully adjusted model, the hazard ratio ( HR) of entering primary outcome events was 2.29-fold (95% CI 1.27-4.11, P=0.006) for men with hyperuricemia and 1.85-fold (95% CI 1.01-3.37, P=0.045) for women with hyperuricemia compared with those with normal uric acid. In the post-match fully adjusted model, the HR of entering primary outcome events was 2.41-fold (95% CI 1.18-4.93, P=0.016) for men with hyperuricemia and 1.83-fold (95% CI 0.91-3.67, P=0.091) for women with hyperuricemia compared with those with normal uric acid. In the pre-match fully adjusted model, the HR of entering renal outcome events was 2.68-fold (95% CI 1.47-4.88, P=0.001) for men with hyperuricemia and 1.81-fold (95% CI 0.99-3.33, P=0.056) for women with hyperuricemia compared with those with normal uric acid. In the post-match fully adjusted model, the HR of entering renal outcome events was 2.89-fold (95% CI 1.36-6.15, P=0.006) for men with hyperuricemia and 1.81-fold (95% CI 0.88-3.72, P=0.106) for women with hyperuricemia compared with those with normal uric acid. Conclusion:Hyperuricemia may be associated with IgAN progression, and it has a more significant effect on male IgAN patients.

Objective: To investigate the impact of maternal X chromosome aneuploidies on cell free DNA (cf-DNA) prenatal screening. Methods: After genetic counseling, invasive prenatal diagnosis was provided for the 124 cases with high risk of sex chromosome aneuploidie (SCA) indicated by cf-DNA prenatal screening. For cases with discordant results of fetal prenatal diagnosis and cf-DNA prenatal screening, maternal leukocyte was collected for copy number variation sequencing (CNV-seq) to detect whether the maternal X chromosome was carrying variations. Results: Totally, 124 cases with high risks of SCA indicated by cf-DNA prenatal screening, 9 cases refused to take invasive prenatal diagnosis, while the remaining 115 cases received. Among the 115 cases, 41 cases received accordant results with cf-DNA prenatal screening while 74 cases discordant. Among the 74 cases with discordant results, 19 cases were indicated with maternal X chromosome variations by maternal leukocyte CNV-seq, which accounting for 25.7% (19/74) of the SCA false positive cases, and 15.3% (19/124) of all SCA cases. Conclusions Pregnant women with X chromosome variations may affect the results of cf-DNA prenatal screening, resulting in false positive or false negative outcomes, it should be emphasized that the cf-DNA results may be affected by maternal X chromosome variations. In cases with discordant results of prenatal diagnosis and cf-DNA prenatal screening, maternal leukocyte CNV-seq is recommended to find the reasons of false positive or negative results. And cf-DNA prenatal screening is not recommended for pregnant women who are already known with X chromosome variations.