Real-time measurement of total nitrogen for agricultural runoff based on multiparameter sensors and intelligent algorithms.

Real-time monitoring of non-point source (NPS) pollution is challenging owing to the minute-scale change in runoff flow and concentration under rainfall condition. In this study, we proposed a real-time measurement method for total nitrogen (TN) by combining the timeliness of sensor detection and the accuracy of intelligent algorithms, based on the physical and chemical relationships between TN and sensor-measured indexes. Extra tree regression was selected as the TN inversion algorithm, which has high precision, high computational efficiency, and better ability in over-fitting control. The results show that: (1) the real-time inversion algorithm of TN can achieve the monitoring frequency at the minute scale (<5 min); (2) the method performs well (R2>0.9) when the training and testing datasets are from similar environmental backgrounds (fields or ditches); (3) in the case of partial variable missing, this method can still realize TN inversion, and the prediction accuracy is acceptable (R2>0.7) under the number of missing variables (n) ≤ 2, which makes up for the flaws of missing or abnormal data caused by sensor malfunctions. Overall, the proposed real-time measurement method of TN has stable data acquisition, high precision, and high monitoring frequency. In addition, the method is not limited by cloudy, rainy, or nighttime conditions. Compared with methods such as laboratory test, remote sensing inversion, and water quality automatic monitoring station, our method has obvious advantages in runoff monitoring of NPS pollution, which mainly occurs in small and micro water bodies. The new real-time measurement of TN for runoff may provide important technological support for pre-warning and emergency control of NPS pollution.

Intraosseous schwannomas of the jaws: 2 case reports and review of the literature.

Schwannomas are one of the benign neoplasms originating from the neural sheath. Soft tissues of the head and neck are the most common sites of occurrence; however, intraosseous schwannomas are rare. This article documents 2 cases of intraosseous schwannoma that presented as a submandibular mass and provides a review of the literature on intraosseous schwannomas.

[The curative effects of bone mesenchymal stem cells transplanted into rats with Sjogren's syndrome].

PURPOSE: To study the curative effects, survival rate, migration and differentiation of bone mesenchymal stem cells (BMSCs) transplanted into rats with Sjogren's syndrome. METHODS: Model of Sjogren's syndrome was created in rats. BMSCs were isolated and cultured by using the preceding method. Then the pretreated BMSCs were identified and labeled by enhanced green fluorescent protein. BMSCs marked with enhanced green fluorescent protein (EGFP) or PBS were injected into the SMG of the Sjogren's syndrome rats via open surgery.Total static saliva flow rate was determined in rats. The daily amount of water in the normal group, the model group, the model treatment group and the model treatment control group was recorded. The survival rate, migration and differentiation of the BMSCs transplanted in the treatment group under fluorescence microscope was recorded. Student's t test was used for data analysis using SPSS 12.0 software package. RESULTS: Compared with the model treatment control group, the total static saliva flow rate of the model treatment group increased significantly, and the water they drank decreased significantly (P<0.05). In addition, BMSCs were distributed along the injection tract mostly in the first week,then BMSCs were mainly distributed in the stroma between the acinar in the second week and were distributed over other areas four weeks later. Immunohistochemical staining of amylzyme was not observed at the first week after transplantation. And at the 8th week the expression of amylzyme in the cytoplasm of the transplanted BMSCs was observed by immunohistochemical only in the model treatment group. CONCLUSION: Transplantation of BMSCs has certain treatment effect on Sjogren's syndrome.