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A series of seven novel 1-aryl-1,2,3-triazole derivatives bearing a 4-(phenothiazin-10-ylmethyl) moiety were designed using a molecular hybridisation approach and synthesised by alkyne/azide click chemistry. Most of the synthesised compounds exhibited moderate to good antiproliferative activity (IC50 values: 0.5 to 6.7 μM) against stomach, oesophagus, prostate, breast and liver cancer cell lines, but a compound containing a 4-chlorophenyl moiety showed better activity against all cell lines than 5-fluorouracil. [ABSTRACT FROM AUTHOR]

Objective To discuss effect of FK506 nanospheres used at different time on the regeneration of allogeneic nerve after transplant. Methods Single emulsion-solvent evaporation method (O/W) was adopted to prepare the FK506 nanospheres and the tibial nerve of rats after allogeneic transplantation. FK506 nanospheres were used in group A after operation immediately, in group B in 24 h after operation, and in group C in 3 d after operation while FK506 nanospheres were not used in group D; in the 4th, 8th and 12th week after operation respectively, general observation of transplanted nerves, histological examination, image analysis of myelinated fibers, wet-weight determination of musculi triceps surae, retrogradely labeling of neurons by the fluorescein and electrophysiological comparison of bilateral tibial nerve were carried out. Results FK506 nanospheres can be degraded and absorbed quickly. The neural regenerations in group A and B were similar, which were both much better than those in group C and D. The difference was statistically significant and so was the difference between group C and D. Conclusions Drug release rate of FK506 nanospheres is accordant with the regeneration law of damaged nerves and the local application can promote the regenerations of nerves. The effect would be better if the drug is used in earlier period (within 24 h). [ABSTRACT FROM AUTHOR]

Objective To introduce synergetic inactivation of microorganisms in drinking water by short-term free chlorination for less than 15 minutes followed by monochloramination. Methods Indicator microorganisms such as Escherichia coli, Staphylococcus aureus, Candida albicans, and spores of Bacillus subtilis were used to assess the efficiency of sequential chlorination and free chlorination. Results The sequential chlorination was more efficient in inactivating these microorganisms than free chlorination, indicating that synergy was provided by free chlorine and monochloramine. Ammonia addition time, temperature and pH had influences on this synergy. Conclusion The possible mechanism of this synergy might involve three aspects: free chlorine causing sublethal injury to microorganisms and monochloramine further inactivating them; different ability of free chlorine and monochloramine to penetrate and inactivate microorganism congeries; and higher concentration of residual chlorine in sequential chlorination than in free chlorination. [ABSTRACT FROM AUTHOR]

Objective To evaluate the disinfection of wastewater in China. Methods During the SARS epidemic occurred in Beijing, a study of different disinfection methods used in the main local wastewater plants including means of chlorine, chlorine dioxide, ozone, and ultraviolet was carried out in our laboratory. The residual coliform, bacteria and trihalomethanes, haloacetic acids were determined after disinfection. Results Chlorine had fairly better efficiency on microorganism inactivation than chlorine dioxide with the same dosage. Formation of THMs and HAAs does not exceed the drinking water standard. UV irradiation had good efficiency on microorganism inactivation and good future of application in China. Organic material and ammonia nitrogen was found to be significant on inactivation and DBPs formation. Conclusion Chlorine disinfection seems to be the best available technology for coliform and bacteria inactivation. And it is of fairly low toxicological hazard due to the transformation of monochloramine. [ABSTRACT FROM AUTHOR]

Objective To define the influence of some parameters, including assimilable organic carbon (AOC), chloramine residual, etc. on the bacterial growth in drinking water distribution systems. Methods Three typical water treatment plants in a northern city (City T) of China and their corresponding distribution systems were investigated. Some parameters of the water samples, such as heterotrophic plate content (HPC), AOC, CODMn, TOC, and phosphate were measured. Results The AOC in most water samples were more than 100 μg/L, or even more than 200 μg/L in some cases. The HPC in distribution systems increased significantly with the decrease of residual chlorine. When the residual chlorine was less than 0.1 mg/L, the magnitude order of HPC was 104 CFU/mL; when it was 0.5-0.7 mg/L, the HPC was about 500 CFU/mL. Conclusion For controlling the bio stability of drinking water, the controlling of AOC and residual chlorine should be considered simultaneously. The influence of phosphors on the AOC tests of water is not significant. Phosphors may not be the limiting nutrient in the water distribution systems. [ABSTRACT FROM AUTHOR]