Drought resistance of ten ground cover seedling species during roof greening.

Roof greening is an important national policy for maintaining the hydrological balance in China; however, plant growth is limited by drought stress. This study aims to identify strong drought resistant plant species for roof greening from ten common species: Paeonia lactiflora, Hemerocallis dumortieri, Meehania urticifolia, Iris lactea var. chinensis, Hylotelephium erythrostictum, Sedum lineare, Iris germanica, Cosmos bipinnata, Hosta plantaginea, and Dianthus barbatus. By controlling the soil relative water content (RWC), we designed three treatments: moderate drought stress (40±2% 75±2%). After the seedlings were provided different levels of water, their membrane permeability (MP), chlorophyll concentration (Chl), and superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX) activity were measured. Finally, the membership function method was used to assess the drought resistance of these species. The results showed that C. bipinnata and M. urticifolia were not suitable for moderate or severe drought stress and did not survive. The other species presented variations in physiological and biochemical parameters. The MP of He. dumortieri, I. lactea and Ho. plantaginea showed minor changes between the well-watered control and drought stress. Most of the species showed reduced SOD activity under moderate drought stress but increased activity under severe stress. All of the plant species showed decreases in the protective enzymes POD and APX with increasing drought stress. The membership function method was applied to calculate the plant species' drought resistance, and the following order of priority of the roof-greening plant species was suggested: He. dumortieri > I. germanica > I. lactea > D. barbatus > Hy. erythrostictum > S. lineare > Ho. plantaginea > P. lactiflora

Rapid Simultaneous Determination of Three Synthetic Cannabinoids in Urine and Plasma of Rats Using Ultra-High Performance Liquid Chromatography Tandem Mass Spectrometry

Synthetic cannabinoids, a class of psychoactive compounds, are controlled as new psychoactive substances (NPSs) identified by the early warning system (EWS) of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). At present, several new synthetic cannabinoids have appeared in the illegal drug market, including 4-methylnaphthalen-1-yl-(1-pentylindol-3-yl) methanone (JWH-122), methyl (1-(5-fluoropentyl)-1H-indazole-3-carbonyl)-L-valinate (5F-AMB), and methyl 2-(1-(4-fluorobenzyl)-1Hindazole-3-carboxamido)-3-methylbutanoate (AMB-FUBINACA). A convenient, rapid, and highly sensitive analytical method was developed to determine three synthetic cannabinoids in rat plasma and urine. The liquid chromatography tandem mass spectrometry (LC-MS/MS) method was optimized and validated to analyze the three synthetic cannabinoids in rat plasma and urine. The method identified intra-assay precision (1.3–9.0% and 2.8–6.7%), inter-assay precision (3.0–8.6% and 3.9–8.8%), limits of detection (0.003–0.004 ng/mL and 0.00125–0.002 ng/mL) and quantification (0.012–0.016 ng/mL and 0.003–0.005 ng/mL), recovery (95.4–106.8% and 92.0–106.8%) for rat plasma and urine, and the matrix effect (93.4–118.0%) for rat urine, and the correlation coefficients were above 0.99 in the linear range. The established LC-MS/MS method was successfully used to simultaneously detect the JWH-122 and 5F-AMB in rat plasma and JWH-122, 5F-AMB, and AMB-FUBINACA in rat urine. The present study provides methodological support for internal exposure assessment of three synthetic cannabinoids and promotes the quantitative analysis and technical supervision of synthetic cannabinoids