Malachite green (MG) is a dye which has been widely used as a topical fungicide and antiseptic in aquaculture throughout the world. Now,MG has become a highly controversial compound due to its potential highly residual and toxic characteristics in recent years. In the paper,the advances in toxicity,toxicological mechanism,detection methods,metabolism and removal of malachite green and its metabolite were reviewed,and the problems in aquaculture and the safety of aquaculture technology were discussed,in order to make us be aware of potential hazard of malachite green and provide a dependable evidences of safely breeding in aquatic products.

Objective A series of 4 substituted salidroside derivatives were designed and synthesized .Their anti-fatigue effects were investigated .Methods With five-acetyl glucose and different 4-substituted benzyl tyrosols as the starting materi-als ,salidroside derivatives were synthesized through glycosidation and deacetylation reactions .The exercise exhaustive mice model was used to study the anti-fatigue effects of those synthesized derivatives by comparing the loading swimming time of mice .Results 10 novel salidroside derivatives were synthesized .The loading swimming tests showed that the swimming time of the mice in the positive group (salidroside) and 3a-1 group (phenethyl-β-D-glucoside) was longer than that in the control group with statistically significant difference(P<0 .05) .The swimming times for other groups were similar to control group with no statistically significant difference .Conclusion This synthetic method for salidroside derivatives was convenient and feasible for large production .The 4-hydroxyl groups on the benzene ring of salidroside and its derivatives may be the active site responsible for their anti-fatigue activity .

An epidemiological investigation was carried out on a local cluster of outbreak caused by imported cases of Coronavirus Disease 2019 (COVID-19) in rural areas of Chengdu in December 2020, to find out the source of infection and the chain of transmission. According to
COVID-19 ; Disease Outbreaks ; Epidemics ; Humans ; Quarantine ; SARS-CoV-2