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Biomedical subjects

D Cheng

Publications and source records attributed to D Cheng.

147 records · Page 9Linked to original sources

Aerodynamic adsorption of permeable chemical protective suit.

A new laboratory apparatus and method were developed to test the protective ability of a permeable chemical protective suit (PCPS). The key features of this method are using a wind tunnel system and an aerodynamic model that could incorporate the complicated flow pattern around the protective clothing. This method illustrates the process of the PCPS system performance and can provide a system assessment through bench-scale experiments. A new aerodynamic adsorption equation for PCPS breakthrough curve calculation based on an aerodynamic model has been suggested, and the calculated breakthrough curves of benzene vapor on PCPS conform to the experiment curves.

Adsorption↗

Comparison of the central nervous system activity of the aqueous and lipid extract of kava (Piper methysticum).

The central nervous activity of the aqueous extract of kava was examined in mice, and compared to the effect of the lipid-soluble extract. The aqueous extract caused a loss of spontaneous activity without loss of muscle tone. No hypnotic effect was seen, but some analgesia was produced. The anticonvulsant effect against strychnine was very slight and there was no evidence of local anesthetic action. There was a slight anti-apomorphine effect and tetrabenazine-induced ptosis was decreased. The lipid-soluble extract (kava resin) also decreased spontaneous motility, together with a marked reduction of motor control. Hypnosis, determined by loss of righting reflex, was produced, analgesia was marked, and a local anesthetic action evident. Kava resin also decreased apomorphine-induced hyperreactivity and partially reversed tetrabenazine-induced ptosis. Kava resin produces a greater range of pharmacological actions than the aqueous extract, and the latter is orally inactive in mice and rats. The pharmacological effects of kava ingestion appear to be due to the activity of the compounds present in the lipid-soluble fraction.

Animals↗