Gas concentration monitoring system for small and medium-sized coal mines based on gas-sensing detection and single-chip control

This paper is aimed at the actual conditions of disaster caused by gas in small and medium-sized coal mines. A new gas concentration monitoring system for coal mines is developed on the basis of gas-sensing detection and single-chip control. The monitoring system uses the tin oxide as the main material of N-type semiconductor gas sensors, be- cause it has good sensitive characteristics for the flammable and explosive gas （ such as methane, carbon monoxide）. The QM-N5-semiconductor gas sensor is adopted to detect the output values of the resistance under the different gas con- centrations. The system, designedly, takes the AT89C51 digital chip as the core of the circuit processing hardware structure to analyze and judge the input values of the resistance, and then achieve the control and alarm for going beyond the limit of gas concentration. The gas concentration monitoring system has man）, advantages including simple in struc- ture, fast response time, stable performance and low cost. Thus, it can be widely used to monitor gas concentration and provide early wamings in small and medium-sized coal mines.

Relationship between plasma risperidone concentrations and clinical features in chronic schizophrenic patients in China

BACKGROUND Prior studies have noted great variability in the plasma levels of risperidone(RIS).Plasma concentrations of RIS and its active moiety are highly variable and depend on absorption,metabolism,and other predictors of metabolic dysregulation;however,these factors are poorly understood and the association between metabolic change and change in psychopathology is uncertain.AIM To ascertain the characteristics of chronic schizophrenic patients treated with RIS,and to assess their relationship with plasma RIS levels.METHODS This was a descriptive cross-sectional study of 50 patients with a diagnosis of schizophrenic psychosis treated with RIS in a psychiatric service.The plasma concentrations of RIS and its metabolite 9-hydroxyrisperidone were determined by high performance liquid chromatography.The patients’demographic and clinical characteristics,and psychopathologies were assessed,and the associations between clinical variables and plasma levels of RIS were explored.RESULTS Male patients received higher doses of RIS than female ones,but plasma concentrations of RIS and risperidone+9-hydroxyrisperidone(active moiety)were higher in female patients.Age and the mean scores of the general psychopathology subscale of the Positive and Negative Syndrome Scale(PANSS)were significantly positively correlated with plasma concentrations of risperidone+9-hydroxyrisperidone adjusted for weight and dose in all 50 subjects.In male subjects,we found a statistically significant positive correlation between the concentrations of risperidone+9-hydroxyrisperidone in plasma/(dose×kg)and age,mean PANSS negative subscale scores,mean PANSS general psychopathology subscale scores,and mean PANSS total scores.CONCLUSION Long-term use of RIS should be closely monitored in older patients and females to minimize the risk of high concentrations which could induce side effects.

The clinical value of enzyme-multiplied immunoassay technique monitoring the plasma concentrations of cyclosporine A after renal transplantation

The feasibility and the clinical value of the enzyme-multiplied immunoassay technique （EMIT） monitoring of blood concentrations of cyclosporine A （CsA） in patients treated with CsA were investigated after kidney transplantation. The validation method was performed to the EMIT determination of CsA blood concentration, the CsA whole blood trough concentrations （Co） of patients in different time periods after renal transplantation were monitored, and combined with the clinical complications, the statistical results were analyzed and compared. EMIT was precise, accurate and stable, also with a high quality control. The mean postoperative blood concentration of CsA was as follows： 〈1 month, （281.4± 57.9）ng/mL; 2 - 3 months, （264.5 ± 41.2） ng/mL; 4 - 5 months, （236.4 ± 38.9） ng/mL; 6 - 12 months, （206.5± 32.6）ng/mL; 〉12 months, （185.6± 28.1）ng/mL. The toxic reaction rate of CsA blood concentration within the recommended therapeutic concentration was 14.1%, significantly lower than that of the none-recommended dose group （37.2%） （P〈0.05）; the transplantation rejection rate was 4.4%, significantly lower than that of the none- recommended dose group （22.5%） （P〈0.05）. Using EMIT to monitor the blood concentration of CsA as the routine laboratory method is feasible, and is able to reduce the CsA toxicity and rejection significantly, leading to achieving the desired therapeutic effect.