Muscle residue depletion of chloramphenicol (CAP), sulphamethoxazole (SMZ) and oxytetracycline (OTC) following oral administration was evaluated in shrimp, Penaeus chinensis under field conditions. Three groups of shrimps were cultured in tanks filled with seawater and fed a commercial medicated diet containing 2000 mg kg(-1) CAP, SMZ and OTC, respectively, twice daily for 3 days. Sampling was conducted at different intervals (0, 0.5, 1, 1.5, 2, 3, 4, 8, 10, 12, 16, 24, 36, 48, 72, 96, 120, 144, 168 h) after the cessation of medication. Drug analysis was carried out by HPLC. The elimination half-life (t(1/2)) of CAP was 10.04 h, the elimination half-life (t(1/2)) of SMZ was 5.68 h and that of OTC was 16.12 h. If the EU MRPL value of 0.3 ng/g for CAP and MRL value of 0.1 microg/g for SMZ and OTC quoted for muscle from finfish is extended to shrimp muscle, extrapolation of the data indicates that it would be passed after a 139.7 h (95% CI=132.0-144.4 h), 30.6 h (95% CI=27.2-33.1 h), 90.3 h (95% CI=87.9-92.5 h) withdrawal period for CAP, SMZ and OTC in shrimp muscle, respectively. 相似文献
China’s pilot free trade zone (PFTZ) is an important national strategy to achieve high-quality development, so it is necessary to discuss the effect of PFTZ implementation on green total factor productivity (GTFP). Based on the data from 279 cities in China from 2004 to 2018, this study takes the establishment of PFTZ as a quasi-natural experiment and uses the difference-in-differences (DID) method to systematically evaluate the effect of PFTZ on urban GTFP. The empirical results of this paper are shown as follows: Firstly, the construction of PFTZ has a significant effect on urban GTFP, and this effect has increased gradually over time. Secondly, the construction of PFTZ mainly promotes the urban GTFP by increasing the level of science and technology innovation, reducing government intervention and improving the level of human capital. Thirdly, the effect of PFTZ construction on GTFP is more pronounced in regions with earlier waves of PFTZ and in western regions where environmental concerns are higher. In addition, there is a significant positive linkage between the construction of the PFTZ and the Belt and Road Initiative to improve the urban GTFP. The findings of this paper enrich the relevant literature on PFTAs and sustainable development and provide a theoretical basis for further promotion of PFTZ construction.