Objective To make a passive personal sampler for the determination of the styrene in the air. Methods To make a passive personal sampler for the determination of the styrene in the air. Results Under the condition of wind velocity of 100-600 cm/s, relative humidity of 40%-80% and temperature of 10-40 ℃, the sampling flux of the passive sampler was 61.8 ml/min, the capacity was 5.95 mg, the shortest sampling time was 30 min, the self life was at least 30 days, the storage stability was at least 14 days, the RSDs were 8.07%-9.37%. Conclusion This new kind of passive personal sampler can be used as a new device for the determination of the styrene in the air.

Objective To observe the effect of aloe on intestine motility in the old costive mice and investigate the mechanism for aloe promoting an intestinal motility. Methods The content of aloin in aloe powder was determined by high performance liquid chromatography(HPLC).The old mice aged 15 months were randomly divided into 6 groups(10 in each group):blank control,positive control,constipation model,low-dose aloe,middle-dose aloe,high-dose aloe plus model.The mice of with equivalent volume of distilled water.On the eighth day,the mice except control group were given Compound Diphenoxylate to establish constipation model. With the black Indian ink as marker,the first time of black stool discharge,the character and weight of the stool,and the ink propulsion rate by intestines in mice were observed respectively.The serum level of nitric oxide(NO)was determined by spectrophotometry. Results The content of aloin in aloe powder was 0.266%.Compared with constipation model group,aloe groups in different dose decreased the first black stool time and increased stool grains and weight in 6 hours of constipated mice.The ink propulsion rates of intestines in the aloe groups were significantly higher than that of model group as well.The NO level in high-dose aloe group decreased more significantly compared with model group(P＜0.05),and there was a negative correlation between the serum NO level and propulsion rate of intestines(r=-0.346.P＜O.05). Conclusions Aloe could promote the mobility of intestine and ameliorate the constipation of mice,which might attribute to the decrease of the serum NO level.

Hexanes ; adverse effects ; Humans ; Occupational Injuries ; chemically induced ; Pyrroles ; adverse effects ; Trauma, Nervous System ; chemically induced

OBJECTIVETo determine the normal reference value of pyrrole adducts in urine in young people in a university in Shandong, China, and to provide a reliable basis for the clinical diagnosis of n-hexane poisoning.

METHODSA total of 240 college students were randomly selected. After excluding 32 ineligible students, 208 subjects were included in this study, consisting of 104 males and 104 females, with a mean age of 21?3 years (range: 18 to 24 years). Morning urine was collected from each subject. The content of pyrrole adducts was determined by chromatometry.

RESULTSThe content of pyrrole adducts in both male and female obeyed a positively skewed distribution. The median level of pyrrole adducts in male subjects was 0.88 nmol/ml, and the reference value was 0.14-3.92 nmol/ml. The median level of pyrrole adducts in female subjects was 0.93 nmol/ ml, and the reference value was 0.09-3.27 nmol/ml. Student's t test identified no statistical difference in pyrrole adduct level between male and female subjects (t=0.15, P>0.05).

CONCLUSIONThe median level of pyrrole adducts in normal young people is 0.91 nmol/ml, and the reference value is 0.11-3.95 nmol/ml.

Adolescent ; China ; Female ; Hexanes ; poisoning ; Humans ; Male ; Pyrroles ; urine ; Reference Values ; Universities ; Young Adult

Objective To evaluate the efficacy of berberine in preventing brain injury induced by hepatic ischemia-reperfusion ( I∕R) and the relationship with glycogen synthase kinase 3 beta ( GSK-3β) activity in mice. Methods Forty-eight healthy clean-grade male C57BL∕6 mice, weighing 20-25 g, were randomized into 3 groups (n=16 each) using a random number table method: sham operation group (S group), hepatic I∕R group (I∕R group) and berberine group (B group). The model of 70％ liver I∕R injury was established by clamping the portal vein and hepatic artery supplying left and middle lobes of the liver in mice anesthetized with 2％ pentobarbital sodium 40 mg∕kg. In B group, berberine 50 mg∕kg was adminis-tered through a gastric tube once a day for 7 consecutive days starting from 7 days before operation. The e-qual volume of normal saline was given instead in S group and I∕R group. The mice were sacrificed at 6 h af-ter reperfusion, brains were removed and hippocampal tissues were harvested for microscopic examination of pathological changes ( with a light microscope) and for determination of cell apoptosis ( by TUNEL) , super-oxide dismutase ( SOD ) activity ( by xanthine oxidase method ) , malondialdehyde ( MDA ) content ( by thiobarbituric acid colorimetric method) , expression of phosphorylated GSK-3β ( p-GSK-3β) and GSK-3β(by Western blot), and opening of mitochondrial permeability transition pore (mPTP). The apoptosis in-dex and p-GSK-3β∕GSK-3β ratio were calculated. Results Compared with S group, the apoptosis index and MDA content were significantly increased, SOD activity and p-GSK-3β∕GSK-3β ratio were decreased, and mPTP opening was increased in I∕R and B groups ( P<0. 05) . Compared with group I∕R, the apoptosis index and MDA content were significantly decreased, SOD activity and p-GSK-3β∕GSK-3β ratio were in-creased, mPTP opening was decreased (P<0. 05), and the pathological changes of hippocampal tissues were significantly attenuated in B group. Conclusion Berberine can prevent the brain injury induced by he-patic I∕R, and the mechanism may be related to inhibiting GSK-3βactivity and thus inhibiting mPTP open-ing in mice.

Objective To evaluate the optimum compatibility of nalbufine combined with ropivacaine for patient-controlled epidural analgesia (PCEA) after cesarean section.Methods A total of 100 parturients who were at full term with a singleton fetus,aged 24-35 yr,with body mass index of 29-33 kg/m2,of American society of Anesthesiologists physical status Ⅱ,scheduled for elective cesarean section under combined spinal-epidural anesthesia,were divided into 4 groups (n =25 each) using a random number table method:sufentanil 0.5 μg/ml plus 0.15％ ropivacaine group (SR group),nalbufine at final concentration of 0.2 mg/ml plus 0.15％ ropivacaine group (N1 R group),nalbufine at final concentration of 0.4 mg/ml plus 0.15％ ropivacaine group (N2R group) and nalbufine at final concentration of 0.4 mg/ml plus 0.1％ ropivacaine group (N3Rgroup).PCEA solution was prepared correspondingly after surgery,and all the drugs were diluted to 100 ml in normal saline in each group.The PCA pump was set up to deliver a 0.5 ml bolus dose with a 15-min lockout interval and background infusion at 2 ml/h.Visual analog scale scores of incisional pain and anduterine contraction pain were maintained＜4.Ramsay sedation scores were recorded at 8,12,24 and 48 h after surgery.The total pressing times of PCEA were recorded within 48 h after surgery.The development of adverse reactions such as nausea,vomiting,skin itching,numbness of lower extremity,urinary retention and respiratory depression was recorded in the analgesia period.Venous blood samples were collected before surgery and at 24 and 48 h after surgery for determination of plasma prolactin concentrations,and the time of colostrum was recorded.Neonatal nerve and adaptive capacity was assessed and scored.Results Compared with group SR,the total pressing times of PCEA were significantly reduced in N2R and N3R groups (P＜0.05),and no significant change was found in the total pressing times of PCEA in group N1R (P＞0.05).Compared with group N1R,the total pressing times of PCEA were significantly reduced in N2R and N3 R groups (P＜0.05).There was no significant difference in the total pressing times of PCEA between group N2R and group N3R (P＞0.05).The Ramsay sedation score was 2 in four groups.There was no significant difference in numbness of lower extremity,plasma prolactin concentrations or neonatal nerve and adaptive capacity scores among four groups (P＞0.05).Conclusion Nalbufine at final concentraction of 0.4 mg/ml mixed with 0.1％ ropivacaine is the optimum compatibility when used for PCEA after cesarean section.