Objective To explore unexplained syncope (UPS) morbidity of elementary and middle school students in Changsha city.Methods Four thousand two hundred and fifteen students aged 5 to 18 years from six fulltime elementary or middle schools were randomly selected and the survey was conducted by giving them 4 215 copies of questionnaires and they were categorized into 3 groups:key school group(n =1 062),normal school group(n =1 310) and peasant laborer dependent's school group (n =1 349).Three thousand seven hundred and twenty-one copies of returning questionnaires (88.28％) were collected.Results 1.Morbidity:among 3 721 students there were 738 students(19.83％) who had once or more symptom of UPS.And the morbidity of middle school students was higher than elementary school students (28.87％ vs 7.96％,x2 =252.11,P ＜ 0.01).The morbidity of key school students was higher than normal school and peasant laborer dependent's school students (25.99％ vs 16.34％ vs 18.38％,x2 =40.93,P ＜ 0.01).2.Onset age:the onset age of UPS was 6-18 (14.23 ± 2.70) years old.3.Gender difference:for the middle school group,the morbidity of female students was higher than male students(31.34％ vs 26.49％,x2 =6.06,P ＜ 0.05).But for the elementary school group (male 9.04％ vs female 6.68 ％,x2 =2.85,P ＞ 0.05) and the total secondary school students (male 18.67％ vs female 21.12％,x2 =3.51,P ＞ 0.05),there was no significant difference between genders.Conclusions The UPS morbidity of students in Changsha is 19.83％.There are differences in age,school and gender.

The root of Peucedanum harry-smithii var. subglabrum was extracted with methanol, then separated with solvents at different polarity into four fractions: aqueous (H2O), ethyl acetate (AcOEt), chloroform (CHCl3) and petroleum ether (DAB-6). From AcOEt psoralen, bargapten, xanthotoxin, marmesin, umbelliferone, scopoletin, (+/-) peuformosin, Pd-I b, (+/-) selinidin, praeruptorin D were isolated by column chromatography on silica gel, using petroleum ether/ethyl acetate as eluent. The structures of the coumarins were identified by 1H-NMR and 13C-NMR.
Apiaceae ; chemistry ; Coumarins ; chemistry ; isolation & purification ; Magnetic Resonance Spectroscopy ; methods ; Plant Roots ; chemistry ; Umbelliferones ; chemistry