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.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.
6.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.
7.Nerve stimulator with single-phase constant-current pulse
Guangqing ZHOU ; Guangjie CHEN ; Xi LI ; Xuefei YU
Chinese Medical Equipment Journal 2003;0(12):-
M PU employed as control center,the nerve stimulator can produce different stimul ation modes easily.The high-quality constant-current pulse and the safety of th e patient are ensured through two-steps current stabilizer,pulse width monitor and the float to ground.Both needle electrode and surface electrode can be used to achieve supramaximal stimulation.
8.The construction of Alzheimer′s disease rats model and the effects of puerarin on rat spatial learning and memory
Dong LI ; Yin TIAN ; Yu GONG ; Xi WANG
Chongqing Medicine 2016;45(16):2180-2181,2185
Objective To research the effects of puerarin on Alzheimer′s disease(AD) rats spatial learning and memory dis‐order induced by Aβ1‐42 .Methods Bilateral hippocampal injection of Aβ1‐42 was used to induced AD model rats .All rats under‐went gavage administration with puerarin with different dose for 28 d since the 3rd day after the construction of model ;and the Morris water maze was used to test the spatial learning and memory ability of rats .Results The model group rats showed obvious learning and memory disorder ,and the ability of learning and memory disorder of rats in the high ,medium and low dose of puerarin interven‐tion group were significantly improved .Conclusion Puerarin can improve the spatial learning and memory ability of AD model rats .
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