Objective: To compare the effects of immediate versus delayed post-space preparation on the bond strength of fiber posts and the fracture resistance of roots after root canal obturation using iRoot SP and the single-cone technique, and to provide an experimental basis for the selection of the timing of clinical post-space preparation. Methods: This study was approved by the Medical Ethics Committee of the institution, and written informed consent was obtained from all participants. Seventy-two extracted human single-rooted premolars were randomly divided into two groups (n = 36 each): the immediate post-space preparation group (post-space preparation performed immediately after root canal obturation) and the delayed post-space preparation group (post-space preparation performed 1 week after root canal obturation). Cleanliness of the root canal walls was assessed with a dental microscope after preparation in both groups; the ultrastructural characteristics of the dentinal surface were examined via scanning electron microscopy; the fracture resistance of roots was measured with root fracture resistance tests; the bond strength of the fiber posts was measured with the thin-slice push-out test; and the bond failure modes were observed and analyzed under a stereomicroscope. Results: Under dental microscopy, the dentin surface of the immediate post-space preparation group appeared cleaner than that of the delayed post-space preparation group. Scanning electron microscopy revealed that most dentinal tubules remained open in the immediate post-space preparation group, while the tubules in the delayed post-space preparation group showed incomplete patency. The fracture resistance of the immediate post-space preparation group was (2 872 ± 241.5) N and that of the delayed post-space preparation group was (2 934 ± 353.1) N, with no statistically significant difference (t = -0.328, P = 0.751). The push-out bond strength of the immediate post-space preparation group (10.310 ± 2.907) MPa was significantly higher than that of the delayed post-space preparation group (7.917 ± 2.429) MPa, with a statistically significant difference (t = 4.457, P < 0.001). Analysis of failure modes showed that adhesive-to-dental interface failure was the predominant mode in both groups. Conclusion Following root canal obturation with iRoot SP using the single-cone technique, immediate post-space preparation yields superior fiber post bond strength compared to delayed post-space preparation, without compromising root fracture resistance.

Objective To analyze current situation and problems of health manager training in the pilot training areas. Method With the recommendations of health administration deputies in the plot areas of Shanghai, Chongqing and Urumqi, 2 centers for community health services (CHSs) were selected in each area, 9 relative persons were interviewed, 3 focus group discussions (FGDs) involved 18 persons were held totally. The FGDs focused on such questions as“the general information of the training students”“the objectives and purposes of the training in each area”, and so on. Field investigation and qualitative analysis were used to investigate the status quo and main problems of the training of health manager in the pilot areas. Result The problems of the training of health manager existing in the pilot areas mainly are:part of teachers were not fully competent to the training of health manager, training of operant skill was insufficient, training course was not unified, the assessment mechanism was not perfect. Conclusion Optimizing the construction of teachers team, standardizing the training content, increasing the time of operating skills training, establishing a unified and standardized assessment mechanism are essential.

Objective To investigate the correlation of bone mineral density (BMD) with plasma Klotho levels and its related factors in type 2 diabetic patients (T2DM) . Methods BMD was measured by Dual-energy X-ray absorptiometry (DEXA) in 159 T2DM patients. The patients were divided into three groups:normal bone mass, reduced bone mass and osteoporosis. The fasting plasma levels of Klotho were detected in these patients using enzyme linked immuno sorbent assay (ELISA), clinical and biochemical parameters also were tested, the difference and related factors were compared and analyzed in each group. Results Plasma Klotho levels were not significantly different among the three groups (4.95±0.48 vs 4.96±0.47 vs 4.91±0.49,P>0.05) . BMD at the first, second, third, fourth and total lumbar spine, femoral neck, trochanter and total body were not associated with plasma Klotho levels in these patients (P>0.05) . Age, diabetic duration, HDL-C and BMI were independent determinants for BMD in T2DM patients. Conclusions BMD might be not associated with plasma Klotho level in T2DM patients. But age,diabetic duration,HDL-C and BMI are associated with reduced BMD and osteoporosis in T2DM patients.

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.

Objective To evaluate the value of MR angiography in thrombolytic therapy of acute ischemic stroke. Methods According to inclusion criteria, 65 patients who also having large vessel occlusion were selected, and they were performed rt-PA treatment (38 patients) and routine treatment (27 patients) within 3-6 hours of onset of symptoms, respectively. Mann-Whitney U test and chi square test were performed to compare the clinical and MR imaging baseline index and the clinical outcome between the two groups respectively. Clinical outcome was assessed after 3 months using a dichotomized modified Rankin scale score.Data were also compared with the combined analysis of the ATLANTIS, ECASS, NINDS rt-PA trials. Resets The difference of clinical outcome in 3 months between the two groups was significant (P < 0. 05) and the median of the two group was 1 and 3, respectively. The ratio of favorable outcome (mRS 0-1) in the two groups was 52. 6% (20/38) and 33.3% (9/27), respectively. Conclusion MR angiography plays an important role in thrombolytic therapy of acute ischemic stroke and it should be used to consummate the conventional inclusion criteria, the patients with large vessel occlusion should be treated by rt-PA.

Objective To obtain an objective assessment of the curative effectiveness of photodynamic therapy (PDT) for port wine stain (PWS), we investigate the relationship between the microvascular perfusion changes of PWS and the blanching of the lesions before and after PDT. Methods Twenty-four patients (18 females and 6 males with a total of 28 lesions) suffering from PWS were treated with PDT. The lesions of various extents were located on the face and neck. After intravenous injection of photosensitizer hepatoporphyrin derivative (HpD), the copper vapor laser was adopted as light source and the lesions of PWS were irradiated. The laser Doppler perfusion imager (LDI) was used to measure the microcirculatory perfusion of PWS before and after PDT and comparison with the normal skin was done.Results All the lesions showed remarkable decrease of tissue perfusion after PDT. It was shown that the mean, maximal and minimal values of tissue perfusion in the pre-treatment group were significantly higher than those in control group (P<0.01). Six months after PDT, the mean, maximal and minimal values of perfusion with the lesions were reduced, with significant difference from pre-treatment group (P<0.01), but no significant difference from control's. The colors of lesions were correlated with decrease of microcirculatory perfusion, which became lightened close to normal skin color without causing any scarring.Conclusions PDT is one of the most effective modalities for PWS. The microcirculation perfusion can reflect the degrees of PWS objectively. The curative effectiveness of PDT for PWS is due to tissue microcirculation response.

Objective:To isolate the variable fragments of heavy chain(VH) against the terminal protein(TP) region of hepatitis B virus(HBV) DNA polymerase(Pol) with protein fragment complementation assay(PCA).Methods:The TP region of HBV secreted by the HepG2.2.15 cells was used as an antigen,and the antibodies were selected with PCA.In this assay,two interacting proteins(target and antibody) are genetically fused to the two halves of the dissected enzyme dihydrofolate reductase.Binding of the two partners reassembles this enzyme and reconstitutes its activity,thus allowing growth on minimal mediem.Results:There were three TP region antigen-specific VHs could be directly in vivo selected with PCA.Sequence analysis showed that each TP-specific VH had a different sequence.Conclusion:Our results show that TP region antigen-specific VH could be directly in vivo selected with PCA.This system were powerful as a routine system for generating antibodies,especially in functional genomics.