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Introduction: An aerobic denitrifier was isolated from the Hua-Jia-Chi pond in China and identified as Pseudomonas mendocina 3-7 (Genbank No. HQ285879). This isolated strain could express periplasmic nitrate reductase which is essential for aerobic denitrification occurred when the dissolved oxygen (DO) level maintains at 3-10 mg L(-1)., Methods: To determine whether the ability of isolated strain is exhibited in the bioremediation of polluted drinking source water, the heterotrophic nitrification and aerobic denitrification characteristics of P. mendocina 3-7 under different cultural conditions such as oxygen level, nitrate and organic concentrations were studied from the nitrogenous balance in the paper., Results and Conclusions: By measuring the nitrogen balance in all experiments under different culture conditions, the removal of total organic carbon and ammonium was positively correlated with total nitrogen removal, especially under high substrate level. With substrate concentration decreasing, ammonium and nitrate removal occurred separately, and ammonium was completely utilized first under low substrate concentration. Compared to that under high substrate level, the specific growth rate of P. mendocina 3-7 was not low under the low substrate level and the pollutant removal efficiencies remained high, which implies the stronger nitrogen removal and acclimatization capacities of the strain in oligotrophic niches.

Background, Aim, and Scope: The start-up pattern of biofilm remediation system affects the biofilm characteristics and operating performances. The objective of this study was to evaluate the performances of the contaminated source water remediation systems with different start-up patterns in view of the pollutants removal performances and microbial community succession., Methods: The operating performances of four lab-scale simulated river biofilm reactors were examined which employed different start-up methods (natural enrichment and artificial enhancement via discharging sediment with influent velocity gradient increase) and different bio-fillers (Elastic filler and AquaMats® ecobase). At the same time, the microbial communities of the bioreactors in different phases were analyzed by polymerase chain reaction, denaturing gradient gel electrophoresis, and sequencing., Results and Discussion: The pollutants removal performances became stable in the four reactors after 2 months' operation, with ammonia nitrogen and permanganate index (COD(Mn)) removal efficiencies of 84.41-94.21% and 69.66-76.60%, respectively. The biomass of mature biofilm was higher in the bioreactors by artificial enhancement than that by natural enrichment. Microbial community analysis indicated that elastic filler could enrich mature biofilm faster than AquaMats®. The heterotrophic bacteria diversity of biofilm decreased by artificial enhancement, which favored the ammonia-oxidizing bacteria (AOB) developing on the bio-fillers. Furthermore, Nitrosomonas- and Nitrosospira-like AOB coexisted in the biofilm, and Pseudomonas sp., Sphaerotilus sp., Janthinobacterium sp., Corynebacterium aurimucosum were dominant in the oligotrophic niche., Conclusion: Artificial enhancement via the combination of sediment discharging and influent velocity gradient increasing could enhance the biofilm formation and autotrophic AOB enrichment in oligotrophic niche.

Lake and reservoir' s eutrophication and its produced microcystins (MCs) have enormous threats to ecological environment and human health. Because the conventional water pollution control techniques have definite limitations, it' s quite urgent to develop new technique to remove the MCs from water environment. MCs can be effectively degraded by specific microbes, and its intermediate and terminal products are non-toxic or low-toxic. This paper summarized the MCs-degrading microbial strains, biodegradation processes, mechanisms, and affecting factors, degraded products and their structural characteristics, and the applications of MCs-degrading microbial strains in water environment restoration. The further research directions were also proposed. It was hoped that this review could provide technical ideas for restoring MCs-polluted lakes and reservoirs and ensuring drinking water safety in China.

Aiming at the carbon source limitation of denitrification in oligotrophic habitat, this paper studied the effects of intermittent aeration on the nitrogen-removal capability of biological contact oxidation remediation system for micro-polluted source water, and approached the feasibility and process mechanism of shortcut nitrification and denitrification in the system. Under the condition of 8 h-16 h anoxic-aerobic phase (I), the remediation system performed stably, and its average removal efficiency of ammonium (NH4+ -N), permanganate index (COD(Mn)), and total nitrogen (TN) was 93.0%, 78.1%, and 19.4%, respectively. Under the condition of 16 h-8 h anoxic-aerobic phase (II), the NH4+ -N and COD(Mn) removal efficiency still maintained at 81.2% and 76.4%, respectively, the accumulation of nitrite (NO2- -N) was significant, and the removal efficiency of TN reached more than 50%. The nitrogen transformation characteristics in the system during a cycle under condition II demonstrated that at the prerequisite of effluent NH4+ -N and DO concentrations reaching the standards, shortening aerobic phase length could maintain the DO concentration at 0. 5 -1.5 mg L(-1) in a long term, inhibit the growth and activity of nitrite-oxidizing bacteria, and thereby, NO2- -N had an obvious accumulation, and the nitrogen removal via shortcut nitrification-denitrification in the biological contact oxidation remediation system for micro-polluted source water was finally achieved.

Objective: To analysis the outcomes and the technique of surgical operation of osteoporotic ankle fracture in the elderly., Methods: One hundred and twenty-eight patients with osteoporotic ankle fracture were treated by surgical operation from January 2003 to December 2008, included 26 males and 102 females, with an average age of 69 years old ranging from 50 to 82 years. According to Lange-Hanson classification, there were 113 cases of supinatio-extorsion, 18 of pronate-extorsion, 5 of supinatio-adduction, 2 of pronate-abduction. The methods of fixation, the complications, and the AOFAS scores after operation were recorded., Results: All the 128 patients were followed up from 6 months to 6 years (averaged in 36 months). Delayed wound healing occurred in 11 cases (8.6%). There was no deep infection, nonunion of the fracture, and revision. The average AOFAS scores after operation was 83.6 +/- 6.3 (the mean pain scores were 33.5 +/- 5.6, the mean function scores were 40.2 +/- 7.4, the mean alignment scores were 10)., Conclusion: Surgical treatment should be the first choice in osteoporotic ankle fracture in most cases. Improved procedures can make the results better.

Two simulated river bioreactors with elastic filler and AquaMats were applied to remediate micro-polluted source water. Under intermittent aeration and gradual increase of aeration intensity, the biofilm reactor with elastic filler was successful start-up within 50 days, and average removal efficiencies of permanganate index, NH4(+) -N were 78.2% and 93.5%, respectively, but the removal efficiencies of the reactor with AquaMats were more than 70% and 80% after two weeks. On the condition of aerobic to anoxic ratio of 3 h: 3 h and aeration intensity of 250 L x h(-1), elastic filler was more efficient for the removal of permanganate index, NH4(+) -N, TN and TP. The pollutant removal of AquaMats was strongly enhanced when the aerobic to anoxic ratio and aeration intensity changed to 2 h :4 h and 120 L x h(-1), which suggested its potential of energy saving. Microscopic observation revealed that the surface of elastic filler was fully surrounded with filamentous bacteria and more inorganic particulate matter after successful start-up of the reactor, and the biofilm attaching to AquaMats was of higher microbial population diversity. The results indicated that elastic filler with homogeneous biofilm had a strong retention capacity for its radial structure, and the AquaMats with microporous structure was more suitable for the enrichment of different functional microorganisms and enhanced the collaborative removal of multiple pollutants.

A treatability study of industrial wastewater containing chlorinated nitroaromatic compounds (CNACs) by a catalytic ozonation process (COP) with a modified Mn/Co ceramic catalyst and an aerobic sequencing batch reactor (SBR) was investigated. A preliminary attempt to treat the diluted wastewater with a single SBR resulted in ineffective removal of the color, ammonia, total organic carbon (TOC) and chemical oxygen demand (COD). Next, COP was applied as a pretreatment in order to obtain a bio-compatible wastewater for SBR treatment in a second step. The effectiveness of the COP pretreatment was assessed by evaluating wastewater biodegradability enhancement (the ratio of biology oxygen demand after 5 d (BOD(5)) to COD), as well as monitoring the evolution of TOC, carbon oxidation state (COS), average oxidation state (AOS), color, and major pollutant concentrations with reaction time. In the COP, the catalyst preserved its catalytic properties even after 70 reuse cycles, exhibiting good durability and stability. The performance of SBR to treat COP effluent was also examined. At an organic loading rate of 2.0 kg COD/(m(3)xd), with hydraulic retention time (HRT)=10 h and temperature (30+/-2) degrees C, the average removal efficiencies of NH(3)-N, COD, BOD(5), TOC, and color in a coupled COP/SBR process were about 80%, 95.8%, 93.8%, 97.6% and 99.3%, respectively, with average effluent concentrations of 10 mg/L, 128 mg/L, 27.5 mg/L, 25.0 mg/L, and 20 multiples, respectively, which were all consistent with the national standards for secondary discharge of industrial wastewater into a public sewerage system (GB 8978-1996). The results indicated that the coupling of COP with a biological process was proved to be a technically and economically effective method for treating industrial wastewater containing recalcitrant CNACs.

Objective: To establish a new visual educational system of virtual reality for clinical dentistry based on world wide web (WWW) webpage in order to provide more three-dimensional multimedia resources to dental students and an online three-dimensional consulting system for patients., Methods: Based on computer graphics and three-dimensional webpage technologies, the software of 3Dsmax and Webmax were adopted in the system development. In the Windows environment, the architecture of whole system was established step by step, including three-dimensional model construction, three-dimensional scene setup, transplanting three-dimensional scene into webpage, reediting the virtual scene, realization of interactions within the webpage, initial test, and necessary adjustment., Results: Five cases of three-dimensional interactive webpage for clinical dentistry were completed. The three-dimensional interactive webpage could be accessible through web browser on personal computer, and users could interact with the webpage through rotating, panning and zooming the virtual scene., Conclusions: It is technically feasible to implement the visual educational system of virtual reality for clinical dentistry based on WWW webpage. Information related to clinical dentistry can be transmitted properly, visually and interactively through three-dimensional webpage.

To prepare doxorubicin-loaded N-octyl-N'-succinyl chitosan polymeric micelle (DOX-OSC) and study the biodistribution of DOX-OSC in mice, DOX-OSC was prepared by dialysis method. By using doxorubicin injection (DOX-INJ) as control, DOX-OSC and DOX-INJ were administered to mice through caudal vein at a dose of 5 mg x kg(-1) body weight. The RP-HPLC method was established to determine the DOX levels in the plasma and other tissues of mice. The tissues distribution and targeting efficiency were evaluated by pharmacokinetic parameters (AUC, MRT) and targeting parameters (Re, Ce and Te). The drug loading and entrapment efficiency of DOX-OSC were (35.8 +/- 0.4)% and (75.3 +/- 1.1)%, respectively. The diameter and zeta potential of DOX-OSC were (174 +/- 12) nm and (-37.1 +/- 3.0) mV, respectively. The transmission electron microscope result showed DOX-OSC with spherical shape. The biodistribution results showed that the concentration of DOX of both DOX-OSC and DOX-INJ decreased rapidly in blood after iv administration. While free DOX levels in blood at 12-96 h were not detectable for DOX-INJ, in contrast, DOX level in blood at 96 h was still found for DOX-OSC. In contrast to DOX-INJ group, DOX-OSC showed a higher targeting efficiency in the liver and spleen. The AUCs of DOX in the liver and spleen were 20.0 and 47.4 times and the MRT were 11.2 and 37.2 times, respectively. And the levels of DOX-OSC in the heart and kidney tissues were significantly reduced. And the drug distribution of DOX-OSC in the heart and kidney tissues were 17.0% and 11.4%, respectively. Hence, DOX-OSC shows an excellent drug loading capabilities and a higher targeting efficiency in the liver and spleen. That the levels of DOX-OSC in the heart and kidney tissues are significantly reduced, might improve the treatment efficacy of DOX and decrease the side effects.

The fundamentals and applications of aerobic sludge granulation technology in wastewater biological treatment are reviewed. The aspects discussed include the general characteristics and microbial structure of aerobic granules, major factors influencing granulation, models of sludge granulation, and their applications. This review is hoped to elucidating a unified interpretation of the formation of aerobic granules under various operation conditions. Aerobic granules are self-immobilized aggregates of bacteria and have a regular and smooth round shape, compact microbial structure and good settling ability. Granulation is depending on the composition and loading of the substrate, appropriate hydraulic selection pressure and operation condition.

The granulation of aerobic sludges for high-rate biodegradation of organic wastewater containing aniline and chloroanilines was investigated in a laboratory-scale sequencing airlift bioreactor ( SABR). Aerobic granules were observed in 15 days after start-up in SABR. After subsequent 83 days, SABR was operated sequentially in superficial air velocity of 2.4cm/s, COD loadings of 1.0-3.6kg/(m3 x d) and (chloro-) anilines loadings increased stepwise to 1kg/(m3 x d), a steady-state performance of aerobic granular SABR was achieved at last, as evidenced by high and stable COD and (chloro-) anilines removal efficiencies of above 90% and 99.9%, respectively. Mature granules with median size of 0.45-2.5mm, minimal settling velocity of 62. 1m/h, and SVI of 56mL/g were developed. Aerobic granular sludge displayed noteworthy SOUR, specific (chloro-) anilines degradation rates, PN content and PN/PS ratio in EPS extracts as 154mgDO/(gVSS x h), 0.18g/(gVSS x d), 28.0 +/- 1.9mg/gVSS and 6.5mg/mg respectively, indicating that they had high activity and ability to withstand high (chloro-) anilines loadings. Phylogenetic analysis of (chloro-) anilines-degrading aerobic granules indicated that beta-, gamma-Proteobacteria and Flavobacteria were dominant classes and the predominance bacteria were closely related to Pseudomonas sp. and Flavo-bacterium sp. Compared to chloroanilines-degrading aerobic granules, the population diversity was higher in the aniline and chloroaniline-degrading aerobic granules.