Preliminary identification of soil fungi for the degradation of polyurethane film.

Polyurethane (PU) is a versatile plastic that boasts high environmental resistance. The biodegradation of PU has become a hot topic of research aimed at finding ways to potentially solve PU pollutants. Identifying microorganisms capable of efficiently degrading PU plastics is pivotal for the development of a green recycling process for PU. This study aimed to isolate and characterize PU-degrading fungi from the soil of a waste transfer station in Luoyang, China. We isolated four different fungal strains from the soil. Among the isolates, the P2072 and P2073 strains were identified as Rhizopus oryzae (internal transcribed spacer identity, 99.66%) and Alternaria alternata (internal transcribed spacer identity, 99.81%), respectively, through microscopic, morphologic, as well as 18S rRNA sequencing. The degradation ability of strains P2072 and P2073 was analyzed through measurement of weight loss, and they exhibited a degradation rate of 2.7% and 3.3%, respectively, for the PU films after 2 months' growth in mineral salt medium (MSM) with PU films as the sole carbon source. In addition, the P2073 strain exhibited protease activity in the presence of PU. To our knowledge, R. oryzae has never been reported as a PU-degrading fungus. This study provides a new perspective on the biodegradation of PU.

[Prevention of dura adherence in spinal canal after microendoscopic discectomy by different methods: a clinical study of 165 cases].

OBJECTIVE: To evaluate the effects of different methods in prevention of post-operational scar formation and dura adherence in the spinal canal after microendoscopic discectomy (MED). METHODS: 165 patients undergoing MED were randomly divided into 3 equal groups: Group A, with the yellow ligament dissected and with the space between vertebral laminae sprinkled with sodium hyaluronate before the closing of the incision; Group B, with the yellow ligament reserved; and Group C, with the yellow ligament reserved and with the space between vertebral laminae sprinkled with sodium hyaluronate before the closing of the incision. All the patients were followed up 2, 4, and 8 weeks, and 1 and 2 years after the operation. Japanese Orthopedic Association (JOA) scoring system was used to evaluate the outcomes. RESULTS: The JOA scores 2 weeks after MED were not significantly different among the 3 groups; and from then on the JOA scores of Groups B and C were all higher than those of group A (A and B: t(4w) = 0.602, t(8w) = 0.701, t(1y) = 0.623, t(2y) = 0.654; A and C: t(4w) = 0.833, t(8w) = 0.759, t(1y) = 0.714, t(2y) = 0.771, all P < 0.05), however, there were not significantly differences at all time points between Groups B and C (B and C: t(2w) = 0.041, t(4w) = 0.135, t(8w) = 0.980, t(1y) = 0.530, t(2y) = 0.103, all P > 0.05). CT showed that a great amount of scar was seen, surrounding the dura mater sac and nerve roots in Group A, and there was a great amount of scar outside the yellow ligament and no remarkable compression of dura mater sac and nerve roots in Groups B and C. CONCLUSION: Reservation of yellow ligament effectively prevents scar adhesion inside the vertebral canal after MED. Sprinkling of sodium hyaluronate is also effective, however, its effect only lasts a short time.