Objective To study the neurotoxic effects of acute exposure of methylmercury at low dose and to provide some experimental data for deeply exploring the early mechanism of neurotoxicity of methylmercury. Methods SD rats were administered with methylmercury chloride by intraperitoneal injection with different doses of 0.05, 0.50 and 5.00 mg/kg and different exposure times of 20 min, 1 h, 4 h, 24 h. Mercury, ACh and AChE contents in rat brains were measured. Results Mercury contents in rat brains significantly increased after 20 min-exposure at both 0.50 and 5.00 mg/kg doses. Significant increase occurred after 4 h exposure at dose of 0.05 mg/kg. ACh and AChE in rat brains significantly changed after 20 min at every dose, showing certain dose-response and time-response relations. Conclusion Changes of ACh and AChE in rat brain after administration of low dose(0.05 mg/kg) and short time(20 min) exposure suggested certain modulation of CNS had been initiated. With the increases of exposure dose and time, methylmercury might begin to accumulate in rat brain and induce the significant changes of ACh and AChE.

Based on Moens-Korteweg model & hydrostatic principle, a simple calibration method by changing vertical distance between heart and radial artery is proposed in this paper. Using hydrostatic pressure to change arterial pressure and pulse wave transmit time, consequently obtain several sets of cardiovascular parameters and finally build up relationship between blood pressure and pulse wave transmit time. Clinical tests have been carried with different age and gender for long and short time monitoring. The comparison results with Sphygmomanometer OMRON EW3152 show its promising accuracy and coincidence feature in blood pressure measurement.
Blood Pressure Determination ; instrumentation ; methods ; Blood Pressure Monitors ; Calibration ; Equipment Design

【Objective】 To analyze the epidemiological characteristics of pertussis in Shaanxi Province from 2012 to 2021. 【Methods】 We collected the information of pertussis cases in Shaanxi Province from 2012 to 2021 by the China Disease Control and Prevention Information System for analyzing the incidence and distribution characteristics. 【Results】 From 2012 to 2021, a total of 8270 cases of pertussis were reported in Shaanxi Province, with the incidence ranging from 0.21 to 6.20 per 100 000 persons, and for an annual average incidence of 2.17 per 100 000 persons. 44.81% (3 706/8 270) occurred from June to September. The annual average incidence in southern Shaanxi, Guanzhong, and northern Shaanxi was 1.78, 2.47, and 1.46 per 100 000 persons (χ²=289.638, P<0.001). The number of patients (proportions) with pertussis aged 0-1, 1-5, 5-10, and ≥10 years was 3 884 (46.96%), 2 869 (34.69%), 1 408 (17.03%), and 109 (1.32%), respectively. The number of patients (proportion) ≤ 2 months old, 3-5 months old, and ≥ 6 months old was 884 (22.76%),1 608 (41.40%), and 1 392 (35.84%) among pertussis patients under 1 year old. 【Conclusion】 The incidence of pertussis in Shaanxi Province basically showed an increasing trend with higher rates between June and September, higher rates in Guanzhong region of the province, and more patients over 5 years old.