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By enrichment culturing of soil contaminated with metribuzin, a highly efficient metribuzin degrading bacterium,Bacillussp. N1, was isolated. This strain grows using metribuzin at 5.0% (v/v) as the sole nitrogen source in a liquid medium. Optimal metribuzin degradation occurred at a temperature of 30ºC and at pH 7.0. With an initial concentration of 20 mg L−1, the degradation rate was 73.5% in 120 h. If the initial concentrations were higher than 50 mg L−1, the biodegradation rates decreased as the metribuzin concentrations increased. When the concentration was 100 mg L−1, the degradation rate was only 45%. Degradation followed the pesticide degradation kinetic equation at initial concentrations between 5 mg L−1and 50 mg L−1. When the metribuzin contaminated soil was mixed with strain N1 (with the concentration of metribuzin being 20 mg L−1and the inoculation rate of 1011g−1dry soil), the degradation rate of the metribuzin was 66.4% in 30 days, while the degradation rate of metribuzin was only 19.4% in the control soil without the strain N1. These results indicate that the strain N1 can significantly increase the degradation rate of metribuzin in contaminated soil. [ABSTRACT FROM PUBLISHER]

Aim: To detect the expression of pleiotrophin (PTN) and N-syndecan in pancreatic cancer and analyze their association with tumor progression and perineural invasion (PNI)., Methods: An orthotopic mouse model of pancreatic cancer was created by injecting tumor cells subcapsularly in a root region of the pancreas beneath the spleen. Pancreatic cancer tissues were taken from 36 mice that survived for more than 90 d. PTN and N-syndecan proteins were detected by immunohistochemistry and analyzed for their correlation with pathological features, PNI, and prognosis., Results: The expression rates of PTN and N-syndecan proteins were 66.7% and 61.1%, respectively, in cancer tissue. PTN and N-syndecan expression was associated with PNI ( P = 0.019 and P = 0.032, respectively). High PTN expression was closely associated with large bloody ascites ( P = 0.009), liver metastasis ( P = 0.035), and decreased survival time ( P = 0.022). N-syndecan expression was significantly associated with tumor size ( P = 0.025), but not with survival time ( P = 0.539)., Conclusion: High PTN and N-syndecan expression was closely associated with metastasis and poor prognosis, suggesting that they may promote tumor progression and PNI in the orthotopic mouse model of pancreatic cancer., Competing Interests: Conflict-of-interest statement: No potential conflicts of interest relevant to this article are reported.

A simple and fast method of solid phase extraction (SPE) disk for the determination of trace acrylamide was developed. Using this new technique along with high performance liquid chromatography (HPLC) and ultraviolet spectroscopy (UV) detection, the feasibility of SPE disk method for rapid enrichment was demonstrated in the determination of trace acrylamide in 500 mL tap water. Active carbon was chosen as the adsorbent to be incorporated into the SPE disk as it gave the best adsorption efficiency. Experimental parameters including solvent, elution volume, elution rate, breakthrough volume were optimized to give the highest efficiency of extraction. Under proper chromatographic conditions, acrylamide was easily separated from other impurities. A linear relationship between peak area and mass concentration in the range 0.05-0.5 mg/L of acrylamide was established with a correlation coefficient of 0.998. The limit of detection was 20 ng/L. The recoveries for acrylamide with different concentrations and volumes ranged from 94.12% to 100.2%. The relative standard deviations (RSDs) were 2.09%-4.51% (n=3). The recovery for acrylamide spiked into a tap water sample was 79. 96%. The method is simple, fast, sensitive and suitable for the determination of acrylamide in tap water.