4.Pollution characteristics and sources of PM2.5 during heating and non-heating periods in Urumqi City in 2021
LI Ting ; ZHANG Ying ; LI Er-shuai ; MA Yu-xi
China Tropical Medicine 2023;23(6):631-
Abstract: Objective To understand the pollution characteristics and sources of PM2.5 in the atmosphere during heating and non-heating periods in Urumqi City in 2021, and provide scientific basis for pollution control during different periods. Method A total of 188 air samples were collected from area A and area B of Urumqi City, and 12 metal elements and 5 water-soluble ions were quantitatively analyzed, and the pollution sources were analyzed by enrichment factor method and principal component analysis method. Results In 2021, the mass concentrations of PM2.5 in areas A and B of Urumqi were 45.0 (20.0, 158) µg/m3 and 28.0 (17.5, 66.0) µg/m3, respectively, with statistically significant difference (Z=-2.870, P<0.05). During the heating period, the concentrations were 110 (68.0, 250) µg/m3 and 61.0 (31.0, 88.0) µg/m3, respectively, with no statistically significant difference (Z=-3.822, P<0.01). During the non-heating period, the concentrations were 18.0 (13.0, 22.3) µg/m3 and 18.0 (12.8, 22.0) µg/m3, respectively, with no statistically significant difference (Z=-0.596, P>0.05). The SNA (the sum of SO42-, NO3-and NH4+) accounted for 71.7% and 23.4% of PM2.5 in A area during heating and non-heating periods, respectively, with statistically significant difference (Z=-8.057, P<0.01); the corresponding proportions in B area were 60.7% and 24.9%, with statistically significant difference (Z=-6.672, P<0.01). During the heating and non-heating periods, the ratios of NO3-/SO42-are 0.63 and 0.54 in A area were 0.63 and 0.54, respectively, with statistically significant difference (Z=-2.382, P<0.05); and the corresponding ratios in B area were 0.72 and 0.53, respectively, with statistically significant difference (Z=-3.182, P<0.05). The ratio of NO3- to SO42- was less than 1 in both heating and non-heating periods in the two areas. and the correlation between five water-soluble ions was significant (P<0.05). The correlation coefficient between NH4+ and SO42-, NO3-and Cl- in A and B areas during heating periods were all >0.9, indicating that NH4+and SO42-, NO3- and Cl- bind in (NH4)2SO4, NH4HSO4, NH4NO3, and NH4Cl. During non-heating periods, the correlation between NH4+ and each ion was slightly lower. During heating periods in area A, Sb, As, Cd, Pb, and Tl were severely enriched (EF>100). During non-heating periods in the same area, As, Cd, Pb, Tl, and Hg were severely enriched (EF>100). During heating periods in area B, Sb, As, Cd, Pb, and Hg were severely enriched (EF>100), and during non-heating periods in the same area, Sb, Cd, and Hg were severely enriched (EF>100). Coal emission, photochemical secondary pollution, motor vehicle exhaust, dust and industrial pollution were the main sources of PM2.5 pollution in the two areas, and the contribution rate of fixed sources was higher than that of mobile sources. Conclusion In 2021, the mass concentration of PM2.5, water-soluble ions and metal elements in Urumqi City were higher in area A than area B, the heating period was higher than the non-heating period, the excess rate of area A was higher than that in area B, and the contribution rate of fixed air pollution was greater than that of mobile sources.
5.Encephalic lymphomatoid granulomatosis.
Li YU ; Zhen-Xi LIU ; Sha XIAO ; Cheng-Yi LUO
Chinese Journal of Pathology 2005;34(2):121-122
6.Application of micro transesophageal echocardiography (micro-TEE) in neonat and infant cardiac surgery
Li DONG ; Xiaojing MA ; Xi YU ; Yuan YUAN ; Jingjing WANG
Chinese Journal of Ultrasonography 2015;24(11):948-950
Objective To evaluate the value of phased array probe of transesophageal echocardiography miniature (micro-TEE) in the neonatal and infant cardiac surgery intraoperation.Methods Micro-TEE probe was used in children with weight ≤5 kg undergoing cardiac surgery to detect the atrial and ventricular cavity size,the left and right ventricular outflow tract diameter were detected by transthoracic echocardiography(TTE) 3-7 d after operation,and compared with the measured value immediately after the TEE.Results Before and after intubation,airway index not statistically significant (P > 0.05).Preoperative TEE and TTE inspection results were consistent with intraoperative diagnosis.Postoperative TEE measuring intracardiac structural data (each room,chamber size and left and right ventricular outflow tract diameter) and postoperative TTE measurement value representing the difference was not statistically significant (P > 0.05).Conclusions Micro TEE intraoperative guardianship of low birth weight infants is safe and feasible,and can supplement and improve the preoperative diagnosis,and can accurately and timely evaluate postoperative curative effect.
7.Risk factors for repeat use of pulmonary surfactant in the treatment of respiratory distress syndrome in the term and near-term neonate
Jing YU ; Huaping ZHU ; Ning LI ; Xi CHEN ; Shiwen. XIA
Chinese Journal of Neonatology 2016;31(2):115-119
Objective To identify risk factors associated with repeat use of pulmonary surfactant ( PS) in the treatment of respiratory distress syndrome ( RDS ) in the term and near-term neonate. Methods There were 130term and near-term new borns with RDS who were treated with pulmonary surfactant were enrolled. These infants were categorized into two groups: single-dose group (85 cases) and repeat-dose group (45 cases). The differences in basic information were compared between the two groups, and logistic regression analysis was used to identify the risk factors for repeat use of pulmonary surfactant.Results TherepeatutilizationrateofPSwas34.6℅.The incidence of asphyxia,maternal gestational hypertension, X-ray RDS grade 3-4, the age of first dose PS,respiratory support time in the repeat-dose group was significantly higher than in the single-dose group (P<0. 05). PaO2/FiO2 and the cure rate in the repeat-dose group were significantly lower than in single-dose group ( P<0. 05 ) . The incidence of sepsis, pulmonary hemorrhage, shock and patent ductus arteriosus ( PDA) in the repeat-dose group was significantly higher than in the single-dose group ( P<0. 05). Further logistic regression analysis showed that birth asphyxia ( OR=5. 674 , 95℅CI 1. 378 -23. 354 , the age of first dose of PS (OR=1.092, 95℅CI 1.002 -1.191)and PDA(OR =23.499, 95℅CI 2.348 -235.152)were the independent risk factors for repeat use of pulmonary surfactant.Conclusions Birth asphyxia,the age of first dose PS and PDA are the risk factors for repeat use of pulmonary surfactant in the treatment of RDS in the term and near -term neonate.
8.Comparison of Ulcerative Colitis Models Respectively Induced by Free Drinking and Intragastric Administration of Dextran Sodium Sulfate in Mice
Yu HENG ; Xi LI ; Tao SUN ; Yan ZHANG ; Peng YANG
China Pharmacist 2017;20(4):603-606
Objective:To investigate the differences in related indices of ulcerative colitis (UC) respectively induced by free drinking and intragastric administration of dextran sodium sulfate (DSS) in mice to provide experimental reference for the optimization of UC model.Methods:Totally 30 C57BL/6 mice were randomly divided into the normal control group,free drinking group and intragastric administration group with 10 ones in each.The mice drank water freely with free drinking or intragastric administration of 3% DSS solution at the dose of 4 g·kg-1·day-1 for 7 days to establish the UC model.The differences in disease activity index (DAI),histological damage sore and activity of myeloperoxidase (MPO) among the groups were compared.Results:Two mice died during the experiment in the free drinking group,and DAI of survival mice was (8.8±1.6).There was no death of mice in intragastric administration group,and DAI was (9.0±0.8),and there was no significant difference in DAI between the groups (P>0.05),while the coefficient of variation in the free drinking group was higher than that in the intragastric administration group (18.7 vs 8.6).The colonic histological damage score of the free drinking group and the intragastric administration group was 24.8±4.2 and 27.0±2.8,respectively,which was typical inflammatory change with no significant difference (P>0.05),while the coefficient of variation of the free drinking group was higher than that of the intragastric administration group (16.9 vs 10.4).MPO of the normal control group,free drinking group and intragastric administration group was (0.41±0.03),(2.32±0.34) and (2.05±0.18) U·g-1,respectively.Compared with the normal control group,significant difference in MPO was shown in the free drinking group and the intragastric administration group (P<0.01),while there was no significant difference in MPO between the groups (P>0.05),and the coefficient of variation in the free drinking group was higher than that in the intragastric administration group (14.7 vs 8.8).Conclusion:Both free drinking and intragastric administration of DSS can successfully induce the UC model in mice.Compared with the free drinking group,the intragastric administration group has low mortality rate and low coefficient of variation.Therefore,intragastric administration has more advantages than free drinking in inducing the UC model in mice.
9.Investigation of adjuvant treatment for difficult weaning from mechanical ventilation
Lijing JIA ; Hongliang LI ; Yu BAI ; Xi ZHU
Chinese Critical Care Medicine 2014;(12):849-854
Objective To investigate the value of drug intervention for difficult weaning from mechanical ventilation. Methods A prospective single-blind randomized controlled trial was conducted. 120 patients with difficult weaning from mechanical ventilation encountered in Department of Critical Care Medicine of Peking University Third Hospital from January 2008 to December 2013 were included,and the patients were divided into treatment group and control group according to random number table,with 60 cases in each group. Patients received furosemide therapy in the treatment group 3 days before weaning up to 48 hours after weaning in order to control negative liquid balance. Enema was given the day before weaning to reduce abdominal pressure. On the weaning day,all of the patients received nitroglycerin and beta blocker or cedilanid to prevent or control elevation of blood pressure and heart rate in the process of weaning. All patients in treatment group received anisodamine in small dosage 2 hours before extubation.The patients in control group received conventional treatment without drug intervention. Baseline indexes of two groups were compared,including the heart rate,respiration rate(RR),mean arterial pressure(MAP),pulse blood oxygen saturation(SpO2),blood gas,hemoglobin(HG),albumin(ALB)and creatinine(Cr). The main reasons of difficulty in weaning,sedative and analgesic drug selection,presence of abdominal discomfort before weaning,interval between sputum suction before extubation,liquid balance at the beginning of the investigation and at time of weaning,24 hours and 48 hours after weaning,failures of spontaneous breathing test(SBT),length of mechanical ventilation,length of ICU stay,and total length of mechanical ventilation and total length of ICU stay during hospitalization. Results There was no statistically significant difference in the heart rate,RR,MAP,SpO2,blood gas,HG,ALB,Cr at the beginning of the investigation between the two groups. The main reasons for difficult weaning in both groups of patients were respiratory dysfunction,cardiac insufficiency,and central nervous system dysfunction. The use of propofol combined dexmedetomidine in the treatment group was more frequent than the control group〔16.7%(10/60)vs. 1.7%(1/60),χ2=8.107,P=0.004〕,and there was no statistically significant difference in the use of other combinations of sedative drugs between the two groups. Abdominal discomfort before weaning was milder in treatment group as compared with control group〔10.0%(6/60)vs. 25.0%(15/60),χ2=4.675,P=0.031〕. The interval between sputum suction before extubation in the treatment group was significantly longer than that of the control group〔hours:1(1,2)vs. 1(1,1),Z=-2.209,P= 0.027〕. SBT failure was less frequent in treatment group compared with control group〔times:0(0,1)vs. 1(1,2),Z=-6.561,P=0.000〕. Liquid balance was better in the treatment group than the control group at time of weaning,24 hours and 48 hours after weaning〔at time of weaning:-567.71 (-755.95,-226.41)vs. 1 256.76(472.48,1 796.63),Z=-9.038,P=0.000;24 hours after weaning:-5.03 (-530.28,245.09)vs. 342.28(125.36,613.25),Z=-4.711,P=0.000;48 hours after weaning:115.50(-450.26, 485.00)vs. 330.00(16.25,575.25),Z=-1.932,P=0.053〕. Compared with control group,length of mechanical ventilation〔days:1.0(1.0,2.0)vs. 2.0(2.0,3.0),Z=-6.545,P=0.000〕,ICU stay time〔days:3.0(3.0,4.0) vs. 4.0(4.0,5.0),Z=-6.545,P=0.000〕,and total length of mechanical ventilation〔days:8.0(6.0,12.0)vs. 11.0(8.0,15.0),Z=-4.091,P=0.000〕and total length of ICU stay during hospitalization〔days:12.5(9.2,19.0) vs. 17.0(12.0,29.5),Z=-2.722,P=0.000〕were all significantly shorter in the treatment group. Conclusions Adjuvant drugs therapy is helpful in patients weaning from the mechanical ventilation,and can shorten length of mechanical ventilation and ICU stay time. Propofol,combined dexmedetomidine,is helpful for weaning.