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.
6.Heterogenous acellular dermal matrix seeded with adipose derived stem cells for urethral reconstruction in a rabbit model
Bingwei HUANG ; Sen LI ; Xi YU ; Peng GE ; Jian LIN
Chinese Journal of Urology 2013;34(10):787-792
Objective To assess the feasibility of heterogeneous acellular dermal matrix(ADM)seeded with adipose derived stem cells(ADSC)for urethroplasty in a rabbit model.Methods ADSC were isolated from a rabbit and expanded in vitro,then identified by flow cytometry.We seeded ADSC onto the ADM and made it into tissue-engineered urethra.12 male rabbits were removed 1 cm urethra and divided into experiment group and control group.There were 6 rabbits in each group.Reconstructed urethra with tissueengineered urethra was used in experiment group,while unseeded ADM were used in control group.Urethrography was performed at 6 months after surgery.The animals were scarified at 3 and 6 months after surgery and the repaired urethra were harvested.H&E staining and immunohistochemical staining were performed with cytokeratin AE1/AE3 and smooth muscle desmin makers.Results The morphology of isolated ADSC was with long spindle cross-links,and had multicentral growth.Flow cytometry showed that the ADSC expressed CD166,CD105,CD90 and CD44,but not expressed CD45 and CD13.The cells could growth well on the ADM and showed good biocompatibility with it.All animals could void normally,urethrography showed there was no significant stenosis.3 months after surgery,the experiment group appeared regenerated smooth muscle but not in the control group,both groups did not regenerate urothelium.At 6 months urothelium and smooth muscle cells could be observed in the experiment group,but only the smooth muscle was evident in the control group.Conclusions By applying tissue engineering methods,we can seed the ADSC onto the heterogeneous ADM and make it into tissue-engineered urethra,which can help improve the reconstructive effect of urethra.
7.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.
8.Encephalic lymphomatoid granulomatosis.
Li YU ; Zhen-Xi LIU ; Sha XIAO ; Cheng-Yi LUO
Chinese Journal of Pathology 2005;34(2):121-122
9.Association of fusional convergence and divergence with control ability in children with intermittent exotropia
Tao, FU ; Jing, WANG ; Qing, SU ; Ping, XI ; Yu, LI
Chinese Journal of Experimental Ophthalmology 2016;34(5):456-459
Background Intermittent exotropia is a type of strabismus that between latent extropia and manifest extropia.The assessment of fusional convergence/divergence is important for understanding control ability of exodeviation in children with intermittent exotropia.Objective This study was to analyze the correlations between fusional convergence/divergence and control ability of exodeviation in children with intermittent exotropia.Methods Sixty-three children with intermittent exotropia were recruited in Beijing Tongren Eye Centre from July 2013 to February 2014 under the informed consent of children and their parents.Angle of deviation was measured by wearing prism and covering method alternately.The control ability of exodeviation was evaluated and scored by the Revised Newcastle Control Score (RNCS),and fusional convergence and divergence were measured with 1 Δ-40Δ horizonal prisms and regulating targets.The correlations between the measured parameters of fusional convergence/divergence and control scores of exotropia were analyzed by Spearman rank correlation analysis.Results The mean diopter of the right and left eyes was (-1.95 ± 1.63)D and (-2.01 ± 1.73)D,respectively,and the mean deviation angle for distantly and near was (36.67 ± 15.69) Δ and (38.25 ± 14.83) Δ,respectively,without significant differences between them (diopter:t =-0.13,P>0.05;deviation angle:t =-0.57,P>0.05).Considerably negative correlations were found between the breakpoints of fusional convergence for distant or near and control scores of exodeviation (rs =-0.41,P=0.03;rs =-0.56,P<0.01).No significant correlations were found between the breakpoints of fusional divergence for distantly or near and control scores of exodeviation (rs =0.05,P =0.78;rs =0.04,P <0.75).In addtion,there was no significant correlation between fusional recovery level and control scores (both at P > 0.05).Conclusions Breakpoints of fusional convergence may be useful in grading the severity of intermittent exotropia in children,and it is probably one of the surgical indications of intermittent exotropia.
10.Changes of Amplitude of Ion Channels Currents in Developing Hippocampal Neurons
zhen-biao, LI ; xi-ru, WU ; yu-wu, JIANG
Journal of Applied Clinical Pediatrics 2004;0(11):-
Objective To study the changes of the amplitude of ion channels currents in developing hippocampal neurons.Methods Using whole-cell patch-clamp techniques in cultured hippocampal neurons whose cultured day were 6 d and 16 d,respectively,changes of the amplitude of ion channels currents in developing hippocampal neurons were explored.Results Compared with the hippocampal neuron whose cultured day was 6 d,there were no statistical differences of the amplitude of voltage dependent sodium currents of hippocampal neuron whose cultured day was 16 d.The amplitude of voltage dependent potassium currents of hippocampal neuron whose cultured day was 16 d were significantly increased(P