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Effect of extracts of Pseudostellaria heterophylla at the dose 400 mg/kg on respiratory waves of guinea pigs recorded by a pressure transducer connected to a biology signal collection processing system: (A) citric acid induced. (B) codeine phosphate + citric acid. (C) PEF + citric acid. (D) EtOAcF + citric acid. (E) n-BOHF + citric acid. (F) EtOHE + citric acid. (G) WE + citric acid; (H) Guilong Kechuanning + citric acid.
