Objective To get the weights of 4 evaluating indices in the operation complexity(OC)model of spaceflight.Methods Two weight assignment methods,subjective and objective methods,were adopted.The subjective method was combined with Delphi method,fuzzy analytic hierarchy process(FAHP),and multi-expert set-valued statistics.To get the subjective weights,two trials of survey were carried out among 10 candidate astronauts.The objective method was nonlinear analysis method in SPSS15.The data of the validation experiment for the OC model was analyzed and the objective weights were obtained.Results Two sets of weights were gained.Conclusion The subjective weights are based on the views of multi-experts and can be applied to different operation situations.The objective weights are suitable to be applied in the same operation situation.

Objective To study the changes and mechanism of skin stem cells in microgravity.Methods The skin stem cells of SD rats were used to establish a suspension culture system and compare the proliferation of skin stem cells with 1G gravity.Results The simulated microgravity significantly affected the velocity of skin stem cell sphere proliferation in suspension culture,which was about 12%higher than the 1G gravity group.Transcriptome sequencing showed that 1673 genes were up-regulated and 1409 genes were downregulated;Calcium signaling;cytokine-cytokine receptor interaction and PPAR pathway were different in the two environments.Conclusion Simulation of microgravity can affect the proliferation behavior of skin stem cells in suspension culture by regulating the expression of key signaling pathways,which provides an experimental basis for further research in spatial microgravity environ ment.

Acetylcholinesterase (AChE) is a key enzyme used to detect organophosphorus pesticide residues by the enzyme inhibition method. An accidental discovery of a mutant strain with AChE activity was made in our laboratory during the process of AChE expression by