Comparative assessment of the environmental pollution and marine economic growth of Guangxi and China by using the environmental Kuznets curve fitting model.

This study examined the nexus between per capita gross ocean product (GOP) growth and total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) discharged from land-based sources in Guangxi and China. Multiple pollution indicators, such as red tide area (RTA), seawater quality area (SWQA), and eutrophication area (EA), were used as marine environmental quality indicators, and annual time series data during the period 2010-2019 were employed. The data were analyzed using the environment Kuznets curve fitting model. Results showed that the average annual growth rates of the GOP and gross domestic product (GDP) of China were 9.88% and 10.79%, respectively, and those of Guangxi were 13.62% and 10.02%, respectively. The average annual GOP ratio in GDP for Guangxi and China was 6.59 and 9.47, respectively. The marine tertiary industry was the most dominant marine industry; it accounted for 41.12-50.01% (mean: 46.12%) of Guangxi's GDP and 47-60% (mean: 52.47%) of China's GDP. The TP, COD, SWQA, and EA of Guangxi and the TP, TN, COD, SWQA, and EA of China displayed inverted U-shaped GOP growth. These findings indicate that the marine economic growth and marine environmental quality of Guangxi and China are harmonious. However, TN increased synchronously with marine economic growth in Guangxi. Therefore, the industrial structure must be further optimized, pollutant discharge management must be strengthened, and the harmonious development of Guangxi's marine economy and marine environment needs to be promoted.

[Dynamic observation of brainstem auditory evoked potential and pathological changes of the brain after closed brain injuries in rats].

OBJECTIVE: To investigate the dynamic experiences of pathological changes in brain and the injured role of brainstem auditory evoked potential (BAEP) after closed Mild Traumatic Brain Injury (MTBI) in rat. METHODS: A closed diffuse brain injury model was successfully produced in rat by hit the parietal bone with a spring-droved steel stick. The auditory brainstem response evoked by click at 50Hz stimulating frequency were recorded at pre-trauma, 15 min and 1, 3, 6, 12 h and 1, 2, 4, 7, 10, 14, 21 d after brain injury. The pathological changes of brain were observed under light microscope and the brain edema was detected by wet weight/dry weight rations. RESULTS: The I-V, III-V of BAEP wave inter peak latency (IPL) in MTBI group increased immediately in 15 minutes after injury. The III, V wave peak latency (PL) and I-V, III-V wave IPL became longer than the pre-trauma level in 6, 12 h post-injury (P<0.05). The III, V wave PL and I - III, I - V, III - V wave IPL became longer than the pre-trauma level in 1, 2 d after injury (P < 0.001), the BAEP retuned to normal level in 14 d after brain injury. At 15 minutes after injury, the water content in brain increased and met its peak in 1 d, decreased gradually in 4 d, then decreased slowly and returned to normal level in 10 d after injury. CONCLUSION: The regular changes of BAEP could be an objective tool for evaluating hearing dysfunction after closed mild diffuse traumatic brain injury.