Detection of Ferric Iron Based on Fluorescence Quenching Effect of N-doped Carbon Quantum Dots / 分析化学

The photoluminescence properties of carbon quantum dots depend on their size and the properties of surface functional groups. The N-doped carbon dots ( using small molecular ethylenediamine ) with high quantum yield and excellent dispersibility were synthesized by one-step hydrothermal method with biomass tar that was generated in the reductive smelting process as a precursor. Rapid and accurate Fe3+ detection based on the selective fluorescence quenching effect of N-doped carbon quantum dots was achieved. The results showed that the as-synthesized N-doped carbon quantum dots were regular spherical, uniform in size with an average particle size of 2. 64 nm with a quantum yield of 26. 1%, and the crystal lattice spacing was 0. 25 nm, corresponding to the ( 100 ) facet of graphitic carbon structure. The functional groups on the surface of N-doped carbon quantum dots could interact with Fe3+ to form complex compound by coordination, leading to the fluorescence quenching effect. Fluorescence emission ratios kept a linear relationship with the concentrations of Fe3+ in the range of 0. 23-600 μmol/L with the detection limit of 230 nmol/L.

Detection of Ferric Iron Based on Fluorescence Quenching Effect of N-doped Carbon Quantum Dots / 分析化学

The photoluminescence properties of carbon quantum dots depend on their size and the properties of surface functional groups. The N-doped carbon dots ( using small molecular ethylenediamine ) with high quantum yield and excellent dispersibility were synthesized by one-step hydrothermal method with biomass tar that was generated in the reductive smelting process as a precursor. Rapid and accurate Fe3+ detection based on the selective fluorescence quenching effect of N-doped carbon quantum dots was achieved. The results showed that the as-synthesized N-doped carbon quantum dots were regular spherical, uniform in size with an average particle size of 2. 64 nm with a quantum yield of 26. 1%, and the crystal lattice spacing was 0. 25 nm, corresponding to the ( 100 ) facet of graphitic carbon structure. The functional groups on the surface of N-doped carbon quantum dots could interact with Fe3+ to form complex compound by coordination, leading to the fluorescence quenching effect. Fluorescence emission ratios kept a linear relationship with the concentrations of Fe3+ in the range of 0. 23-600 μmol/L with the detection limit of 230 nmol/L.

Comparison of entecavir and adefovir for the treatment of chronic hepatitis B

The results of several new clinical trials that compared the effectiveness of entecavir (ETV) treatment with that of adefovir (ADV) treatment in patients with chronic hepatitis B (CHB) were published in recent years. However, the numbers of patients included in these clinical trials were too small to draw a clear conclusion as to whether ETV is more effective than ADV. Therefore, a new meta-analysis was needed to compare ETV with ADV for the treatment of CHB. A search of the Cochrane Central Register of Controlled Trials (CCTR), MEDLINE, the Science Citation Index, Embase, the China National Knowledge Infrastructure (CNKI), and the Wanfang Database for relevant studies published between 1966 and 2010 was performed. Trials comparing the use of ETV and ADV for the treatment of CHB were assessed. Of the 2,358 studies screened, 13 randomized controlled clinical trials comprising 1,230 patients (ETV therapy, 621; ADV therapy, 609) were analyzed. The serum hepatitis B virus (HBV) DNA clearance rate obtained in patients treated with ETV was significantly higher than that in patients treated with ADV at the 24th and 48th weeks of treatment (24 weeks: 59.6% vs. 31.8%, relative risk [RR], 1.82, 95% CI: 1.49-2.23; 48 weeks: 78.3% vs. 50.4%, RR, 1.61, 95% CI: 1.32-1.96). The serum HBeAg clearance rate, the HBeAg seroconversion rate, and the ALT normalization rate obtained for patients treated with ETV were also higher than the corresponding values for patients treated with ADV at the 48th week of treatment. The safety profiles were similar between patients treated with ETV and those treated with ADV. The evidence reviewed in this meta-analysis suggests that patients with hepatitis B have a greater likelihood of achieving a viral response and a biomedical response when treated with ETV than when treated with ADV.

Prognostic value of cyclin E and its relation to blood vessel invasion in rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of cyclin E in rectal carcinoma and its prognostic significance.</p><p><b>METHODS</b>Cyclin E expression was examined by Western blotting in tumor tissue samples from 130 potentially resected rectal cancer patients with pathological stages I- III. Blood vessel invasion (BVI) was detected by immunohistochemistry. Multivariate analysis using the COX proportional hazards models was applied to evaluate the independent prognostic tumor markers of rectal cancer.</p><p><b>RESULTS</b>The high expression rate of cyclin E in rectal carcinoma tissue was 23.1%(30/130). Except for a positive correlation with BVI and the gross configuration of tumor, the expression of cyclin E showed no significant relation to other clinicopathological factors. The 5-year disease-specific survival rate of cyclin E high expression group was 29.2%, which was significantly lower as compared to that of cyclin low expression group 70.5% (P<0.05). Multivariate analysis revealed that histology and cyclin E expression were independent prognostic indicators for rectal cancer patients at stages I- III. Compared to those with low expression levels, patients with high cyclin E levels had the hazard ratio (95%CI) for death from rectal cancer for 3.544 (1.528-8.215). In stage I- II, multivariate analysis showed that stronger predictive values of cyclin E expression even were detected. Patients with low cyclin E expression and negative BVI had a significantly better prognosis than those with high cyclin E expression and positive BVI.</p><p><b>CONCLUSIONS</b>The expression of cyclin E is independent prognostic factor in rectal carcinoma at stages I- III. Detecting the expression of cyclin E and/or combined with BVI may help to predict clinical outcome and design further individualized intensive adjuvant treatment.</p>