Preparation of Protein Hybrid Fluorescence Nanoclusters for Rapid Detection of Mercury Ion / 分析化学

One-step green synthetic approach,with bovine serum albumin(BSA) as stabilizer and reductant, was developed for preparation of BSA hybrid fluorescence gold nanoclusters (AuNCs@BSA). The prepared AuNCs@BSA exhibited strong red fluorescence under UV light illumination. Upon excited at 360 nm, the fluorescence spectrum of AuNCs@ BSA exhibited maximum emission peak at 635 nm. AuNCs@ BSA was presented as uniform spherical morphology with diameter at (2.0 ±0.05) nm. The fluorescence of AuNCs@BSA could be quenched by Hg2+because of its metallophilic reaction. Based on the fluorescent spectrometry, a rapid detection system was developed for Hg2+detection in tap water. The AuNCs@BSA amount, pH and buffer system were optimized in this study. According to optimization results, ultrapure water (pH 5.0) was selected to dilute the AuNCs@BSA by 100 times, and 50 μL/well of AuNCs@BSA dilution was applied to detect mercury ion in tap water. Under the optimized conditions, the detection could be completed within 3 min,the fluorescence intensity of the system was linearly proportional to the concentration of mercury ion in the range of 0.5–900 μg/L with linear equations y=-26.76lgx+803.1(0.5-75 μg/L,R2=0.9951) and y=-0.27x+762.02 (75-900 μg/L,R2=0.9959). The limit of detection was 0.14 μg/L(3σ). The average recoveries in spiked tape water samples ranged from 86.8%-113.4% with relative standard deviation of less than 15%. The result implied that the developed method was able to apply to detect mercury ion rapidly, sensitively and conveniently.

Autologous bone marrow stem cell transplantation in critical limb ischemia: a meta-analysis of randomized controlled trials / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Amputation-free survival (AFS) has been recommended as the gold standard for evaluating No-Option Critical Limb Ischemia (NO-CLI) therapy. Early-phase clinical trials suggest that autologous bone-marrow derived cells (BMCs) transplantation may have a positive effect on patients with NO-CLI, especially decreasing the incidence of amputation. However, the BMCs therapeutic efficacy remains controversial and whether BMCs therapy is suitable for all CLI patients is unclear.</p><p><b>METHODS</b>We conducted a meta-analysis using data from randomized controlled trials (RCTs) by comparing autologous BMCs therapy with controls in patients with critical limb ischemia, and the primary endpoint is the incidence of amputation. Pubmed, EBSCO and the Cochrane Central Register of Controlled Trials (to approximately July 25, 2012) were searched.</p><p><b>RESULTS</b>Seven RCTs with 373 patients were enrolled in the meta-analysis. Because serious disease was the main reason leading to amputation in one trial, six studies with 333 patients were finally included in the meta-analysis. Pooling the data of the final six studies, we found that BMCs therapy significantly decreased the incidence of amputation in patients with CLI (odds ratio (OR), 0.37; 95% confidence interval (CI), 0.22 to 0.62; P = 0.0002), and the efficacy had not significantly declined within 6 months after BMCs were transplanted; OR, 0.33; 95%CI, 0.16 to 0.70; P = 0.004 within 6 months and OR, 0.30; 95%CI, 0.11 to 0.79; P = 0.01 within 3 months. The rate of AFS after BMCs therapy was significantly increased in patients with Rutherford class 5 CLI (OR 3.28; 95%CI, 1.12 to 9.65; P = 0.03), while there was no significant improvement in patients with Rutherford class 4 (OR 0.35; 95%CI, 0.05 to 2.33; P = 0.28) compared with controls. The BMCs therapy also improved ulcer healing (OR, 5.83; 95%CI, 2.37 to 14.29; P = 0.0001).</p><p><b>CONCLUSIONS</b>Our analysis suggests that autologous BMCs therapy has a beneficial effect in decreasing the incidence of amputation and the efficacy does not decrease significantly within 6 months after BMCs transplantation. Patients with Rutherford class 5 are suitable for BMCs therapy, while the efficiency in patients with Rutherford 4 needs further evaluation.</p>

Colon-specific delivery tablets of sodium 4-aminosalicylic acid / 药学学报

<p><b>AIM</b>To prepare a new oral colon-specific delivery formulation and to investigate the release profile in vitro and the colon-specific delivery property in vivo in dogs.</p><p><b>METHODS</b>Sodium 4-aminosalicylic acid was selected as the model drug. The combination of Eudragit RL30D and RS30D were used as sustained-release film, and Eudragit FS30D used as enteric film, which was expected to release drug depending on pH and time. The release profile of tablets was studied in three phosphate buffers with the pH 6.5, 7.0 or 7.4 for 12 h after a simulated gastric presoak for 2 h in 0.1 mol x L(-1) HCl. The tablets were radiolabelled with 99mTc to make their release times and positions in the gastrointestinal tract be followed using a gamma camera.</p><p><b>RESULTS</b>For the in vitro study, there was no drug released in 0.1 mol x L(-1) HCl for 2 h, and release occurred slowly when pH was above 6.5. Drug was released faster while pH was higher. For the in vivo study, the coated tablets remained intact in the upper gastrointestinal tract, and drug release began after the colonic arrival. The uncoated tablets, however, disintegrated in the stomach of the dogs rapidly.</p><p><b>CONCLUSION</b>The coating could protect the drug until the tablets reached the ascending colon, where drug was released slowly for over 10 h.</p>

Influences of copper speciation on toxicity to microorganisms in soils / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the relationship between copper speciation and microbial features (microbial communities and copper tolerance level) in order to determine the adverse effect of different forms of Cu on microorganisms.</p><p><b>METHODS</b>Tessier's sequential extraction procedure was used to qualify the different Cu forms (exchangeable, carbonate bound, Fe/Mn oxide bound, residue and organic matter bound), and the copper tolerance level (expressed as IC50, influence concentration) was measured by the plate-count method.</p><p><b>RESULTS</b>By simple correlation analysis, the IC50 was positively correlated with the concentration of exchangeable Cu (R2 = 0.8204), while weakly correlated with other forms of Cu.</p><p><b>CONCLUSION</b>The bacterial community tolerance increases in the copper-contaminated soil while sensitive bacteria decrease in the copper-contaminated soils. The exchangeable Cu exerts high toxicity to microbial communities.</p>