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.Encephalic lymphomatoid granulomatosis.
Li YU ; Zhen-Xi LIU ; Sha XIAO ; Cheng-Yi LUO
Chinese Journal of Pathology 2005;34(2):121-122
7.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.
8.Effect of ageing on intestinal barrier function in D-galactose-induced rat aging model
Kefen WU ; Xi LI ; Weiying REN ; Yu HU
Chinese Journal of Geriatrics 2013;32(9):1006-1009
Objective To study the changes of intestinal epithelial barrier function in rats with aging.Methods SD rats were divided into 3 groups:3-month-old group (group A),12-month-old group (group B) and 24-month-old group (group C,established by D-galactose injection with the dose of 0.125 g· kg-1 · d-1subcultaneously for 6 weeks) (n=10,each).The terminal ileum was obtained to make microtome section,and the morphology of small intestine mucous membrane,trophonema altitude and thickness were observed under light microscope.Occludin and ZO-1 protein expressions in terminal ileum mucous membrane were detected by immunohistochemistry.The expressions of Occludin and ZO 1 mRNA were determined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).Results The small intestinal mucosa thickness and villus height were lower in group C and B than in group A [thickness:(87.6± 6.32) μm,(131.8± 5.22) μm vs.(162.9±7.28) μm; villus height:(56.4±5.38) μm,(76.7±5.40) μm vs.(108.1±6.42) μm;both P<0.05].The small intestinal mucosa thickness and villus height was lower in group C than in group B (both P<0.05).Occludin and ZO-1 protein expressions in small intestine tissue were reduced in group C and B as compared with group A [Occludin protein:(2.23±0.60)%,(4.21±0.61)% vs.(12.31±0.94)%; ZO-1 protein:(2.03±0.54)%,(4.02±0.65) % vs.(12.21±0.81)% ; both P<0.05],and Occludin and ZO-1 protein expressions were less in group C than in group B (both P<0.05).The levels of Occludin and ZO-1 mRNA in small intestine tissue were reduced in group C and B as compared with group A [Occludin:(0.20±0.03),(0.38±0.02) vs.(0.66±0.03) ; ZO-1:(0.18±0.03),(0.37±0.02) vs.(0.63±0.03); both P<0.05],and Occludin and ZO-1 mRNA expressions were less in group C than in group B (both P < 0.05).Conclusions The small intestinal mucosa thickness and villus height are reduced,the levels of Occludin and ZO-1 expressions are significantly decreased in small intestinal mucosa,and the intestinal barrier function is impaired with rat aging.
9.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.
10.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.