[Removal of Nitrate Nitrogen by Microbial Photoelectrochemical Cell: PANI/TiO2-NTs as a Photoanode].

The use of microbial photoelectrochemical cells (MPECs) for the removal of contaminants is a cost-effective and environment-friendly method. Based on the preparation of polyaniline/titanium dioxide nanotube array (PANI/TiO2-NTs) composite photoelectrodes, an MPEC system comprising PANI/TiO2-NTs photoanode and biocathode was constructed and the removal performance of nitrate nitrogen (NO3--N) was studied. The experimental results showed that the PANI/TiO2-NT electrode exhibited the best photoelectric performance when the PANI loading time was 80 s. Compared with the TiO2-NTs electrode, the photocurrent density doubled. The light-driven MPEC system could realize autotrophic denitrification without an external voltage. The biodegradation of NO3--N conformed to the pseudo first-order kinetics. The higher the photoresponse current density, the better the denitrification performance of the system. When the initial concentration of NO3--N was 25 mg·L-1 and the photoresponse current density increased from 0.17 mA·cm-2 to 0.67 mA·cm-2, the average denitrification rate increased from 0.83 mg·(L·h)-1 to 2.83 mg·(L·h)-1. High-throughput sequencing of the biocathode microbial membranes revealed that Pseudomonas (27.37%) was the dominant bacteria. It was considered that the photogenerated electrons generated by the PANI/TiO2-NTs photoanode were transmitted to the cathode through an external circuit. Pseudomonas and other microorganisms with autotrophic denitrification and electrochemical activity directly used the electrons on the electrode as the sole electron donors for autotrophic denitrification reaction.

[Arthroscopic denervation of patella combined with microfracture for patellofemoral arthritis].

OBJECTIVE: To explore the clinical effect of knee denervation combined with micro-fracture under arthroscope in the treatment of patellofemoral arthritis. METHODS: From May 2015 to May 2018, 60 patients with knee joint degenerative patellofemoral arthritis were treated, including 28 males and 32 females, aged from 24 to 56(40.5±3.35) years old. Among them, 30 cases underwent arthroscopic debridement alone(control group), 30 cases underwent arthroscopic debridement, peripatellar denervation combined with cartilage cone and patellofemoral articular surface microfracture treatment (treatment group). VAS, Lysholm and Kujala scores were used to evaluate the therapeutic effect. RESULTS: No complications such as wound infection, vascular nerve injury and deep venous thrombosis occurred in all patients. The patients were followed up for 7 to 36 months with an average of 12.5 months. The VAS scores of the two groups were improved 4 weeks after operation, and the improvement of the treatment group was significantly better than that of the control group, the difference was statistically significant (P<0.05). Lysholm and Kujala scores were compared at the last follow-up of the two groups, the improvement of the treatment group was significantly better than that of the control group. CONCLUSIONS: The treatment of patellofemoral arthritis with patellar denervation combined with microfracture can better relieve pain and improve knee function.

[Accordion operation for the bone transport in treating tibial bone defect].

OBJECTIVE: To discuss clinical outcomes of accordion operation for the Ilizarov technique in treating tibial bone defects. METHODS: From January 2014 to June 2016, 22 patients with tibial bone defects were treated by Ilizarov bone-transport technique, including 19 males and 3 females with an average age of 44.04 years old ranging from 23 to 60 years old;the length of the bone defects before the bone transport was 5 to 11 cm with an average 7.68 cm; Cause of injury invlved traffic accidents in 14 cases, fall injury in 3, smashing injury in 4, high drop injury in 1; 6 cases were on the left and 16 cases were on the right. The patients were divided into two groups: 11 cases in accordion group were treated by "accordion operation" after bone transport was completed;11 cases in control group were treated by the external fixator locked waiting for bone consolidation after bone transport was completed. All patients were followed up for 18 to 36 months with an average time of 27.9 months. There was no statistical significance between two groups, such as sex, age, length of bone defect(P>0.05). Analysis of healing time, healing index and other indicators, and Paley's criterion was used to evaluate the healing effect of bone healing and function recovery of the limb. RESULTS: The result of X-ray evaluation was all patients achieved bone healing. In accordion group, the bone healing time was (365±91) days, the bone healing index was (46.2±3.5) d/cm; in control group, the bone healing time was(435±108) days, the bone healing index was (57.8±3.5) d/cm. There was no statistical significance in the bone healing time between the two groups(t=1.648, P=0.115);There was statistical significance in the bone healing index between the two groups(t=7.754, P=0.000). At the final follow-up, according to Paley's criterion, the result in accordion group was excellent in 9 cases, good in 2 cases; in control group, excellent in 8 cases, good in 3 cases. Score was not statistically significant(z=-0.479, P=0.619). Complications involved nail infection (9 cases in accordion group, 10 cases in control group);local traction pain (2 cases in accordion group, 1 case in control group); axial malalignment>10°(4 cases in accordion group, 3 cases in control group);location difference of the junction of bone defects (3 cases in accordion group, 2 cases in control group);Complications were not statistically significant(P>0.05). CONCLUSIONS: Accordion operation for the Ilizarov technique in treating tibial bone defects can shorten the treatment time and consolidation time, and improve the healing index.