| 1 | Seasonal characterization of components and size distributions for submicron aerosols in Beijing显示文摘Submicron aerosols(PM1)in Beijing were studied using an Aerodyne aerosol mass spectrometer(AMS)from January to October 2008.This paper presents seasonal variations of different chemical components(sulfate,nitrate,ammonium,chloride and organics)and size distributions of PM1.Results show that mass concentration of PM1 was highest in summer,and lowest in autumn.Organics represented the dominant species in all seasons,accounting for 36%-58%of PM1,and their concentrations were highest in winter.Concentrations of inorganic components,sulfate,nitrate,and ammonium were highest in summer. Based on principal component analysis,organics were deconvolved and quantified as hydrocarbon-like and oxygenated organic aerosol(HOA and OOA,respectively).HOA was highest in winter,accounting for about 70%of organics.However,OOA was highest in summer,and had lower values in autumn and winter.A similar diurnal pattern of various components was ob- served,which is higher at nighttime and lower during daytime.HOA increased more dramatically than other species between 17:00 and 21:00 and peaked at noon,which could be related to cooking emissions. OOA,sulfate,nitrate,ammonium and chloride varied with the same trend.Their concentrations increased with solar radiation from 9:00 to 13:00,and declined with weakening solar radiation.Size distributions of all species showed apparent peaks in the range 500-600 nm.Size distributions of organics were much broader than other species,particularly in autumn and winter.Distributions of sulfate,nitrate and ammonium had similar patterns,broadening in winter.Contributions of different species were size-dependent;the finer the particle,the greater the contribution of organics.Organics represented more than 60%of particles smaller than 200 nm,contributing 50%to PM1 in winter.In spring and summer,HOA was the dominant organic fraction for particles smaller than 200 nm, while OOA contributed more to particles larger than 300 nm.In winter,HOA contributed more than OOA to all PM1 particles. | ZHANG YangMei SUN JunYing ZHANG XiaoYe SHEN XiaoJing WANG TingTing QIN MingKai | 2013 | Science China Earth Sciences2013，56，5： | 14 |
| 2 | A central analgesic mechanism of acupuncture for migraine An ongoing functional MRI study显示文摘Shaoyang acupoints are the most frequently used in migraine treatment.However,the central analgesic mechanism remains poorly understood.Studies have demonstrated that single stimulus of the verum acupuncture in healthy subjects can induce significant connectivity or activity changes in painrelated central networks compared with sham acupuncture.However,these findings are not indicative of the central analgesic mechanism of acupuncture at Shaoyang acupoints.Thus,we recruited 100migraine sufferers and randomly assigned them into five groups:Shaoyang uncommon acupoint,Shaoyang common acupoint,Yangming uncommon acupoint,non-acupoint control,and blank control groups.Subjects were subjected to evaluation of curative effects and functional MRI prior to and after10 and 20 acupuncture treatments.All subjects were diagnosed by physicians and enrolled following clinical physical examination.Subjects were observed during 1–4 weeks after inclusion.At the fifth week,the first clinical evaluation and resting functional MRI were conducted.The Shaoyang uncommon acupoint,Shaoyang common acupoint,Yangming uncommon acupoint,and non-acupoint control grousp then were treated with acupuncture,five times per week,20 times in total over 4 weeks.The second and third clinical evaluations and resting functional MRI screenings were conducted following10 and 20 acupuncture treatments.The blank control group was observed during the 5 to 8 week period,followed by clinical evaluation and resting functional MRI.The aim of this study was to examine changes in brain functional activity and central networks in subjects with migraine undergoing acupuncture at Shaoyang uncommon acupoints.This study provides a further explanation of the central analgesic mechanism by which acupuncture at Shaoyang acupoints treats migraine. | Lei Lan Yujie Gao Fang Zeng Wei Qin Mingkai Dong Mailan Liu Taipin Guo Fanrong Liang | 2013 | Neural Regeneration Research2013，8，28： | 3 |
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