Objective To explore the effects of the meteorologic factors on air pollutants and to establish a model of relationship between the meteorologic factors and concentration of air pollutants. Method The data of SO2,NO2 and PM10 concentration in the air and the related meteorologic factors (daily average,maximum and minimum atmospheric pressure and daily atmospheric pressure difference,daily average,maximum and minimum air temperature,monthly rainfall,daily average and minimum relative humidity and wind speed) from January 2002 to December 2007 were collected. The correlation between the air pollutant levels and related meteorologic factors was analyzed by the multiple regression models with SPSS 11.5 software and multiple regression equations were established. Results Minimum relative humidity was negatively correlated with the concentration of SO2 and NO2 in atmosphere . Daily minimum air temperature was negatively correlated with the concentration of NO2 in atmosphere. Daily average relative humidity and wind speed were negatively correlated with the concentration of PM10 in atmosphere. Daily atmospheric pressure difference was positively correlated with the concentration of PM10 in atmosphere. Multiple regression equations of the concentration of SO2,NO2 and PM10 in atmosphere and meteorologic factors have statistical significances. Conclusion The meteorologic factors have some effects on the air pollution levels. By using the correlation of meteorologic factors and the concentration of air pollutions,multiple regression equations can be established.

Objective To analyze time-space variation of air pollutants(SO2,NO2,PM10) and the correlation among them in inner region and outer region of Shenzhen from 2002 to 2007.Methods The daily concentration means of SO2,NO2 and PM10 during 2002 to 2007 from the nine environmental monitoring sites in Shenzhen were collected.The determination was conducted according to the Ambient Air Quality Criteria.Results From January to December,variation of air concentration of SO2,NO2 and PM10 met the "V" shape in inner region and outer region of Shenzhen in 2002-2007,which was descending from January to June and ascending from June to December.The level of the air pollutants in inner region and outer region was higher in fall and lower in summer.The air pollution level of the inner region was increasing from 2002 to 2004,then decreased in 2005,but increased again in 2006 and 2007.The tendency of the outer region was similar with the tendency of the inner region from 2002 to 2006,but the level of pollutants decreased in 2007.The air concentration of SO2 in outer region was higher than that in inner region in 2002-2007.The air concentration of NO2 and PM10 in outer region was higher than that in inner region in 2002 to 2006,but lower in 2007.The air concentration of SO2 in inner region and outer region in 2002-2007 was under the limit of grade 2 according to the GB 3095-1996,near to grade 1 in inner region.The air concentration of NO2 and PM10 was under the limit of grade 3 and grade 2 respectively.There was a close correlation among the levels of SO2,NO2,PM10 in Shenzhen.Conclusion The air quality in Shenzhen is better in China.The time-space variation of the air pollutants is obvious and a close correlation exists among the air pollutants.

Objective To investigate the water quality of finished water of the centralized water supply system in Shenzhen according to 106 indexes of water quality standards of China.Methods The collection and preservation of water samples was according to the standard examination methods for drinking water-collection and preservation of water samples (GB/T 5750.2-2006).The sanitary quality of the finished water samples collected from 35 centralized water supply systems in cities were determined and evaluated according to the Standards for Drinking Water Quality (GB 5749-2006) in May of 2008.Results The average qualified rate of drinking water was 82.9% (29/35) in Shenzhen.Among 106 indexes,4 indexes (such as turbidity,aluminum,manganese and free chlorine residue) exceeded the standard limits in degrees in some centralized water supply system.Conclusion According to the results of the present paper,it is considered that the water quality of the product water from the centralized water supply system in Shenzhen is good.

Objective To evaluate the effect of emulsified isoflurane on cognitive function in rats.Methods Seventy-two adult male SD rats,aged 8 weeks,weighing 250-300 g,were randomly divided into 3 groups:normal control group (group C,n =12),intralipid group(group E,n =12),and 8％ emulsified isoflurane group ( group EI,n =48).Morris water maze test was performed at 2 h after administration in group E and at 2 h,1,7,14 d after administration in 12 rats at each time point in group EI.The escape latency,staying time at the original platform quadrant,frequency of crossing the original platform and swimming speed were recorded.Orbital blood samples were taken from 6 rats in each group after water maze test for determination of the plasma corticosterone concentration,and then the animals were sacrificed and their hippocampi were removed for determination of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) contents.Brains were removed from another 6 rats in each group after water maze test for determination of the expression of BDNF and NGF in DG,CA3,CA2,CA1 of hippocampus.Results Compared with group C,in group EI the escape latency at 2 h after administration was prolonged,staying time at the original platform quadrant was shortened,the expression of BDNF in DG and CA3 of hippocampus was down-regulated and the BDNF content in hippocampus was decreased at 2 h and 1 d after administration( P ＜ 0.05 or 0.01).The escape latency was shortened and staying time at the original platform quadrant was prolonged at 7 and 14 d after administration,the content of NGF in hippocampus was increased at 1,7 and 14 d after administration and the expression of BDNF in DG and CA3 of hippocampus was up-regulated at 1d after administration as compared with those at 2 h after administration in group E1( P ＜ 0.05 or 0.01).There was no significant difference in the variables mentioned above between groups E and C( P ＞ 0.05 ).There was no significant difference in plasma corticosterone concentration among the 3 groups ( P ＞ 0.01 ).Conclusion The mechanism by which emulsified isoflurane results in transient cognitive impairment in rats is related to down-regulating the expression of BDNF in hippocampus,but not related to corticosterone and NGF.

ObjectiveTo investigate the effect of isoflurane anesthesia on plasma cortisol,and brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in hippocampus in rots.MethodsThirty-six adult male SD rots,aged 10 weeks,weighing 250-280 g,were randomly assigned into 6 groups:control group (group C,n =6) and O2 group (group O,n =6),isoflurane group (group Ⅰ,n =24).The rats were exposed to 2％ isoflurane for 2 h (FGF 3 L/min) in group Ⅰ.While the rats were only exposed to the pure oxygen in group O.Six rats in each group were chosen to perform Morris water maze test after inhalation of pure oxygen was stopped in group O,and at 2 h,and at 1,7 and 14 days after the end of administration in group Ⅰ.The escape latency and swimming distance in place navigation test,and the number of crossing the platform and swimming distance in spatial probe test were recorded.After water maze test was terminated at each time point,blood samples were taken from the fossa orbitalis to determine the plasma cortisol concentration and the hippocampal tissue was obtained for measurement of the contents of BDNF and NGF.ResultsCompared with group C,the number of crossing the platform was significantly decreased,the swimming distance was significantly shortened,and the plasma cortisol concentration was significantly decreased in spatial probe test in group O,and the escape latency and swimming distance were significantly prolonged at 1 day after the end of administration in plaee navigation test,and the number of crossing the platform and the content of BDNF in the hippocampal tissue were significantly decreased,and the swimming distance was significantly shortened in spatial probe test in group Ⅰ (P ＜ 0.05 or 0.01 ).Conclusion lsoflurane anesthesia exerts a transient inhibitory effect on cognitive function in the short term,and promotion of the cortisol release and synthesis of BDNF is involved in the mechanism,but not the synthesis of NGF in hippocampus in rats.

Objective To investigate the effect of emulsified isoflurane anesthesia on the expression of hippocampal amyloid-beta protein (Aβ) and phosphorylation of Tau protein in rats.Methods Seventy-two healthy Sprague-Dawley rats,aged 8 weeks,weighing 250-300 g,were randomly divided into 3 groups:normal control group (group C,n =12),fat emulsion group (group E,n =12),and 8％ emulsified isoflurane group (group EI,n =48).30％ fat emulsion and 8％ emulsified isoflurane 0.15 ml/100 g were slowly injected via the tail vein in groups E and EI,respectively.Morris water maze test was performed 6 days before anesthesia.Twelve animals in each group were chosen at 2 h after administration (T1) in E group,at the corresponding time points in C group,or at T1 and 1,7 and 14 days after administration (T2-4) in EI group and underwent spatial probe tests,and the escape latency was measured.The rats were anesthetized with intraperitoneal 1％ pentobarbital sodium 4 g/100 g after the end of Morris water maze test.Blood samples were taken for determination of the plasma S100 protein concentration.The rats were then sacrificed and brains were removed for determination of the expression of hippocampal Aβ and phosphorylated Tau (p-Tau) protein by immunohistochemistry.Results The escape latency and swimming distance were significantly shorter on 3rd,4th and 5th days than those on 1st day of place navigation test before anethesia (P ＜ 0.01).Compared with group C,the escape latency and swimming distance were significantly prolonged and the time of staying at the original platform quadrant was shortened at T1,and the plasma S100 protein concentration was decreased at T4 in group EI (P ＜ 0.05),and no significant change was found in the each parameter of Morris water maze test,plasma S100 protein concentration,and expression of Aβ and p-Tau protein in group E (P ＞ 0.05).The escape latency and swimming distance were significantly shorter and the time of staying at the original platform quadrant was longer at T2-T4 than at T1 in group EI (P ＜ 0.05).Conclusion Emulsified isoflurane anesthesia exerts no effect on the expression of hippocampal Aβ and phosphorylation of Tau protein,indicating that hippocampal Aβ and Tau protein are not involved in emulsified isoflurane anesthesia-induced cognitive dysfunction in rats.