OBJECTIVE: Acoustic rhinometry (AR) was performed to standardize the measurement techniques, result interpretation and reference values of nasal cavity volume (NV) in preschool children. METHOD: (1) Nasal cavity models were used to test the correlations between NV, minimal cross-sectional area (MCA), and nasal resistance. (2) There were 97 four-year-old and 137 five-year-old children underwent AR test. RESULT: (1) Model tests showed that resist the nce were better correlated with the change of volume than the MCA. (2) The average bilateral NV in preschool children was (2.03 +/- 0.4) ml. No significant gender and age difference were observed (P>0.05). CONCLUSION Volume measurement appears more sensitive and reliable than the MCA in assessing nasal patency. The AR result interpretation and normative NV values in preschool children are introduced.
Airway Resistance ; Child, Preschool ; Female ; Humans ; Male ; Nasal Cavity ; anatomy & histology ; physiology ; Reference Values ; Rhinometry, Acoustic ; methods

Myocardial ischemia/reperfusion injury(MIRI)occurs after cardiopulmonary bypass open heart surgery,cardiovascular intervention and thrombolytic therapy,which is the most important cause of cardiac insufficiency,heart fail-ure,and even death in patients after treatment.In recent years,studies have found that the release of endogenous active peptides can alleviate the production of MIRI,and regulating the function and action of endogenous peptides may be one of the most effective ways to treat MIRI.Dipeptidyl peptidase 4(DPP4)is an important serine protease in mammals,with enzymatic activity to hydrolyze endogenous peptides.Its primary physiological function is to metabolize short peptides,in-cluding growth factors,hormones,etc.This review aims to better understand and search for effective therapeutic targets by elucidating the impact of DPP4 on the hydrolysis of endogenous peptides in MIRI,and ultimately provide new ideas for the therapeutic effects of MIRI.