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 .

Neuropeptide Y receptor Y8(NPY8R)is a fish-specific receptor with two subtypes,NPY8AR and NPY8BR.Changes in expression levels during physiological processes or in vivo regulation after ventricular injection suggest that NPY8BR plays an important role in feeding regulation;this has been found in only a few fish,at present.In order to better understand the physiological function of npy8br,especially in digestion,we used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)technology to generate npy8br-/-Japanese medaka(Oryzias latipes).We found that the deletion of npy8br in medaka larvae affected their feeding and digestion ability,ultimately affecting their growth.Specifically,npy8br deficiency in medaka larvae resulted in decreased feed intake and decreased expression levels of orexigenic genes(npy and agrp).npy8br-/-medaka larvae fed for 10 d(10th day of feeding)still had incompletely digested brine shrimp(Artemia nauplii)in the digestive tract 8 h after feeding,the messenger RNA(mRNA)expression levels of digestion-related genes(amy,lpl,ctra,and ctrb)were significantly decreased,and the activity of amylase,trypsin,and lipase also significantly decreased.The deletion of npy8br in medaka larvae inhibited the growth and significantly decreased the expression of growth-related genes(gh and igf1).Hematoxylin and eosin(H&E)sections of intestinal tissue showed that npy8br-/-medaka larvae had damaged intestine,thinned intestinal wall,and shortened intestinal villi.So far,this is the first npy8br gene knockout model established in fish and the first demonstration that npy8br plays an important role in digestion.

To summarize the nursing care of a patient with acute myocardial infarction complicated with cardiogenic shock before operation.The main nursing points are as follows:in the acute stage,the integrated rescue was implemented with rapid on-machine coordination of external cardiopulmonary resuscitation,multidisciplinary collaboration to ensure safe patient transport;during the bridging period,the combined operation care of extracorporeal membrane oxygenation,intra-aortic balloon counter pulsation and continuous kidney replacement therapy was carried out with goal-oriented anticoagulation care,prevention of catheter-related infection with the assistance of mechanical circulation,and neurological function monitoring.The patient successfully passed the waiting period for heart transplantation and underwent heart transplantation 21 days after admission.With the follow-up for 1 year,the patient recovered well.

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