[Effects of biochar application patterns on soil nutrients and nitrogen- and phosphorus-related enzyme activities in Phaeozem and Luvisol]. / ç”Ÿç‰©ç‚­æ–½ç”¨æ–¹å¼å¯¹é»‘åœŸå’Œæ½®æ£•å£¤å »åˆ†åŠæ°®ç£·è½¬åŒ–ç›¸å ³é ¶æ´»æ€§çš„å½±å“.

We investigated the effects of different biochar application patterns on soil nutrient contents and element transformation, with soil samples being collected from two five-year field experiments in Phaeozem and Luvisol amended with biochar at annual low-rate (AL, 22.5 t·hm-2·a-1) and intervalic high-rate (IH, 112.5 t·hm-2·5 a-1). Changes of soil total carbon (C), nitrogen (N) and phosphorus (P) contents as well as the related enzyme activities were measured under different biochar application patterns to provide fundamental information for the straw utilization and soil fertility improvement in agroecosystem. Results showed that total C and organic N contents in AL treatment were significantly higher than those in IH treatment in Phaeozem soil. Compared with the control, the decreases of dehydrogenase activity in AL treatment was more pronounced than that in IH treatment in Phaeozem soil, and the increases of protease activity in IH treatment was pronounced than that in AL treatment in Luvisol. Compared with Luvisol soil, the application of biochar had stronger effect on total soil C and organic N contents in Phaeozem soil. Application of biochar significantly increased the activities of soil dehydrogenase and protease in Luvisol soil, but decreased the activity of soil dehydrogenase. Soil types and biochar application patterns interacted to affect soil C and N contents, microbial metabolic activity, N- and P-related enzyme activities. In summary, soil types and biochar addition affected soil properties and microbial characteristics, which would provide important information for straw application and soil management.

Electroacupuncture facilitates the integration of a grafted TrkC-modified mesenchymal stem cell-derived neural network into transected spinal cord in rats via increasing neurotrophin-3.

AIMS: This study was aimed to investigate whether electroacupuncture (EA) would increase the secretion of neurotrophin-3 (NT-3) from injured spinal cord tissue, and, if so, whether the increased NT-3 would promote the survival, differentiation, and migration of grafted tyrosine kinase C (TrkC)-modified mesenchymal stem cell (MSC)-derived neural network cells. We next sought to determine if the latter would integrate with the host spinal cord neural circuit to improve the neurological function of injured spinal cord. METHODS: After NT-3-modified Schwann cells (SCs) and TrkC-modified MSCs were co-cultured in a gelatin sponge scaffold for 14 days, the MSCs differentiated into neuron-like cells that formed a MSC-derived neural network (MN) implant. On this basis, we combined the MN implantation with EA in a rat model of spinal cord injury (SCI) and performed immunohistochemical staining, neural tracing, electrophysiology, and behavioral testing after 8 weeks. RESULTS: Electroacupuncture application enhanced the production of endogenous NT-3 in damaged spinal cord tissues. The increase in local NT-3 production promoted the survival, migration, and maintenance of the grafted MN, which expressed NT-3 high-affinity TrkC. The combination of MN implantation and EA application improved cortical motor-evoked potential relay and facilitated the locomotor performance of the paralyzed hindlimb compared with those of controls. These results suggest that the MN was better integrated into the host spinal cord neural network after EA treatment compared with control treatment. CONCLUSIONS: Electroacupuncture as an adjuvant therapy for TrkC-modified MSC-derived MN, acted by increasing the local production of NT-3, which accelerated neural network reconstruction and restoration of spinal cord function following SCI.