The cDNA encoding the precursor of cobrotoxin was cloned from the venom gland of the Chinese continental cobra ( Naja naja atra ) by RT-PCR. Its deduced amino acid sequence analysis showed that the mature protein was identical to that identified from the Taiwan cobra ( Naja naja atra ) by protein sequencing technique. The cDNA encoding the mature protein was then subcloned into the expression vector pMAL-P2. The gene of CMl 1, which was formed by ligation of the fragments of the synthetic oligonucleotides, was also cloned into the expression vector pMAL-P2. After induction of IPTG, both of the neurotoxins were overexpressed as soluble fusion proteins which were confirmed by SDS-PAGE and western blotting. The expressed fusion proteins was purified by sepharose 6B-amylose affinity chromatography and DEAE-sepharose FF chromatography. Both of the recombinant proteins achieved after digestion by factor Xa showed the in vivo toxicity.

Objective: To analyze the prevalence and related factors of suicide ideation among nurses in different levels of hospitals in Shandong Province, and to analyze the relationship between them. Methods: From June to July 2020, 1644 nurses in Shandong Province were surveyed by multi-stage stratified cluster sampling. The suicidal ideation of nurses was investigated by suicidal ideation screening. Social support and mental health were measured by the perceived social support scale (pass) and kessler10 scale respectively. The simple coping style scale (SCSQ) was used to evaluate the coping styles of the subjects when they encountered problems. Logistic regression was used to analyze the influencing factors of suicidal ideation, Amos software was used to establish the path model of suicidal ideation related factors, and the maximum likelihood estimation was used to test the path model coefficient. Results: The incidence of suicidal ideation among nurses in secondary hospitals during their career was 8.44%, and that in tertiary hospitals was 11.66%. There was no significant difference in suicidal ideation among nurses at all levels in secondary hospitals (P>0.05) . The main factors related to suicidal ideation were unmarried and others (OR=0.362, 95%CI=0.155, 0.844, P=0.019) , social support (OR=1.084, 95% CI=1.059, 1.109, P=0.000) and mental health status (OR=0.921, 95% CI=0.890, 0.953, P=0.000) . The suicide ideation of skilled nurses in tertiary hospitals was higher than that of other levels (P<0.05) . The related factors of suicide ideation mainly included unmarried and others (OR=0.369, 95% CI=0.214, 0.636, P=0.000) , night shift (OR=1.889, 95%CI=10.57, 3.377, P=0.032) , general self-rated social status (OR=2.377, 95%CI=1.031, 5.483, P=0.042) , physical disease (OR=2.747, 95%CI=1.601, 4.714) , P=0.000) , Social support (OR=0.960, 95%CI=1.042, 1.077, P=0.000) and mental health status (OR=0.942, 95%CI=0.922, 0.963, P=0.000) . Social support and mental health have a direct effect on suicidal ideation. Self-assessment of social status, social support and physical disease can affect suicidal ideation by affecting mental health. Conclusion: It is necessary to pay more attention to the mental health status of nurses at different levels in different hospitals during their career, improve their social support level, and improve their cognition of the practice environment.
Hospitals ; Humans ; Mental Health ; Nursing Staff ; Risk Factors ; Social Support ; Suicidal Ideation