Vertical Evolution of Boundary Layer Volatile Organic Compounds in Summer over the North China Plain and the Differences with Winter

The vertical observation of volatile organic compounds(VOCs)is an important means to clarify the mechanisms of ozone formation.To explore the vertical evolution of VOCs in summer,a field campaign using a tethered balloon during summer photochemical pollution was conducted in Shijiazhuang from 8 June to 3 July 2019.A total of 192 samples were collected,23 vertical profiles were obtained,and the concentrations of 87 VOCs were measured.The range of the total VOC concentration was 41-48 ppbv below 600 m.It then slightly increased above 600 m,and rose to 58±52 ppbv at 1000 m.The proportion of alkanes increased with height,while the proportions of alkenes,halohydrocarbons and acetylene decreased.The proportion of aromatics remained almost unchanged.A comparison with the results of a winter field campaign during 8-16 January 2019 showed that the concentrations of all VOCs in winter except for halohydrocarbons were more than twice those in summer.Alkanes accounted for the same proportion in winter and summer.Alkenes,aromatics,and acetylene accounted for higher proportions in winter,while halohydrocarbons accounted for a higher proportion in summer.There were five VOC sources in the vertical direction.The proportions of gasoline vehicular emissions+industrial sources and coal burning were higher in winter.The proportions of biogenic sources+long-range transport,solvent usage,and diesel vehicular emissions were higher in summer.From the surface to 1000 m,the proportion of gasoline vehicular emissions+industrial sources gradually increased.

Effect of naloxone on level of plasma beta-endorphin in neonates with severe asphyxia

β-endorphin is the most actively endogenous substance of cerebral endorphin. When combined with opiate receptor specially, it manifests a strong morphine-like activity and can decrease sensitivity of central nervous system to carbon dioxide so as to inhibit breath. OBJECTIVE： To observe the changes of content of plasma β-endorphin in neonates with severe asphyxia after naloxone treatment in a large dosage. DESIGN： Randomized controlled observation. SETTINGS： Department of Pediatrics, Shenzhen Shajing People＇s Hospital; Center of Pediatrics, Guangzhou Zhujiang Hospital. PARTICIPANTS： A total of 97 neonates with severe asphyxia including 57 boys and 40 girls were selected from Neonatal Intensive Care Unit, Department of Pediatrics, Shenzhen Shajing People＇s Hospital from January 2004 to November 2005. Their gestational age was （38±3） weeks, body mass was （3.2±1.7） kg, and hospitalization duration was （2.8±2.3） hours. All neonates met the diagnostic criteria of with severe asphyxia and all their parents provided the confirmed consent. METHODS： All neonates were treated with inspired oxygen, sedation, stopping terror, decreasing cranial pressure, maintaining a well blood perfusion and normal level of blood glucose （about 5.0 retool/L）. After hospitalization, 0.1 mg/（kg·d） naloxone hydrochloride （Beijing Sihuan Pharmaceutical Technology Co., Ltd.; certification： HI0900021; bullet preparation; 0.4 mg/ampoule） was intravenously dribbled into neonates for 4 - 6 hours, 14 days in total. 2 mL blood was collected from radial artery in neonates at the beginning of hospitalization and at 3 days after naloxone treatment, put in aprotinin-pre-cool tube, mixed evenly, and centrifuged at hypothermia. Plasma was maintained in refrigerator at - 70 ℃. The kit was provided by Neurobiology Department of Shanghai Second Military Medical University of Chinese PLA. Concentration of plasma β-endorphin was measured by using radio-immunity assay.All data were expressed as Mean ± SD and results were compared with paired t test. MAIN OUTCOME MEASURE： Concentration of plasma β-endorphin. RESULTS： All 97 neonates were involved in the final analysis. Concentration of plasma β-endorphin in neonates with severe asphyxia was lower after treatment as compared with that before treatment, and there was significant difference （t = 10.31, P 〈 0.01 ）. CONCLUSION： Naloxone can decrease level of plasma β-endorphin in neonates with severe asphyxia.

Fabrication and characterization of hierarchical porous Ni2+doped hydroxyapatite microspheres and their enhanced protein adsorption capacity

Hydroxyapatite(HAP)is a common bio-adsorbent,which performance depends heavily upon its morphology and microporous structure.In this study,a novel synthesis strategy was proposed for hierarchical porous HAP microspheres by a simple"one-pot"hydrothermal reaction.In the strategy,L-glutamic acid serves as soft template to modulate the morphology and inner crystalline of HAP.To evaluate the application potential,doping Ni^(2+) on hierarchical porous HAP microspheres gives metal chelated affinity adsorbents.The prepared adsorbents show a perfect spherical shape,particles size of 96.6μm,relatively specific surface area of 48.5 m^(2)·g^(-1) and hierarchical pores(mesopores:4 nm and macropores:53 nm).By the adsorption evaluation,it reveals that the Ni^(2+)-HAP adsorbents have high adsorption capacities of275.11 and 97.55 m^(2)·g^(-1) for hemoglobin and bovine serum albumin,respectively,which is comparable to other similar adsorbent.Therefore,this work provides a promising method for high-efficiency hydroxyapatite microspheres for proteins purification.

臭氧生成敏感性的时空分布及“双碳”目标对其的影响

Tropospheric ozone(O3)is a trace gas of great significance for air quality and climate change.In recent years,due to the extensive implementation of emission reduction policies,the concentration of fine particulate matter in many countries has decreased significantly^([1]).In contrast,the global ground-level O3 concentration has increased by approximately 0.25 ppbv/a^([2]).Research shows that developed countries are experiencing a rebound in O3 levels while developing countries are facing more severe O3 pollution problems^([3,4]).Therefore,the prevention and control of O3 pollution is the top priority at this stage and will play a vital role in the longterm improvement of air quality.

柴油车(机)管控是我国空气质量持续改善的关键

自2013以来,我国在大气污染防治方面先后制订并实施了《大气污染防治行动计划》和《打赢蓝天保卫战三年行动计划》.历经8年大气污染防治工作,我国的空气质量显著好转,二氧化硫和细颗粒物浓度大幅降低[1].然而,相关研究表明,臭氧污染日益突出[1].据此,《中华人民共和国国民经济和社会发展第十四个五年规划和2035年远景目标纲要》(简称“十四五”规划)明确指出,现阶段我国大气污染防控的目标为:“推进细颗粒物和臭氧协同控制”.由于氮氧化物和挥发性有机物均为细颗粒物和臭氧的前体物[2],因此“十四五”规划也明确提出“氮氧化物和挥发性有机物排放总量分别下降10%以上”的具体目标.

lncRNA AC005224.4/miR-140-3p/SNAI2 regulating axis facilitates the invasion and metastasis of ovarian cancer through epithelial-mesenchymal transition

Background:Ovarian cancer is one of the most widespread malignant diseases of the female reproductive system worldwide.The plurality of ovarian cancer is diagnosed with metastasis in the abdominal cavity.Epithelial-mesenchymal transition(EMT)exerts a vital role in tumor cell metastasis.However,it remains unclear whether long non-coding RNA(lncRNA)are implicated in EMT and influence ovarian cancer cell invasion and metastasis.This study was designed to investigate the impacts of lncRNA AC005224.4 on ovarian cancer.Methods:LncRNA AC005224.4,miR-140-3p,and snail family transcriptional repressor 2(SNAI2)expression levels in ovarian cancer and normal ovarian tissues were determined using real-time quantitative polymerase chain reaction(qRT-PCR).Cell Counting Kit-8(CCK-8)and Transwell(migration and invasion)assays were conducted to measure SKOV3 and CAOV-3 cell proliferation and metastasis.E-cadherin,N-cadherin,Snail,and Vimentin contents were detected using Western blot.Nude mouse xenograft assay was utilized to validate AC005224.4 effects in vivo.Dual-luciferase reporter gene assay confirmed the targeted relationship between miR-140-3p and AC005224.4 or SNAI2.Results:AC005224.4 and SNAI2 upregulation and miR-140-3p downregulation were observed in ovarian cancer tissues and cells.Silencing of AC005224.4 observably moderated SKOV3 and CAOV-3 cell proliferation,migration,invasion,and EMT process in vitro and impaired the tumorigenesis in vivo.miR-140-3p was a target of AC005224.4 and its reduced expression level was mediated by AC005224.4.miR-140-3p mimics decreased the proliferation,migration,and invasion of ovarian cancer cells.SNAI2 was identified as a novel target of miR-140-3p and its expression level was promoted by either AC005224.4 overexpression or miR-140-3p knockdown.Overexpression of SNAI2 also facilitated ovarian cancer cell viability and metastasis.Conclusion:AC005224.4 was confirmed as an oncogene via sponging miR-140-3p and promoted SNAI2 expression,contributing to better understanding of ovarian cancer pathogenesis and shedding light on exploiting the novel lncRNA-directed therapy against ovarian cancer.

Evolution of boundary layer ozone in Shijiazhuang,a suburban site on the North China Plain

The structure of the boundary layer affects the evolution of ozone(O3), and research into this structure will provide important insights for understanding photochemical pollution.In this study, we conducted a one-month observation(from June 15 to July 14, 2016) of the boundary layer meteorological factors as well as O3 and its precursors in Luancheng County,Shijiazhuang(37°53′N, 114°38′E). Our research showed that photochemical pollution in Shijiazhuang is serious, and the mean hourly maximum and mean 8-hr maximum O3 concentrations are 97.9 ± 26.1 and 84.4 ± 22.4 ppbV, respectively. Meteorological factors play a significant role in the formation of O3. High temperatures and southeasterly winds lead to elevated O3 values, and at moderate relative humidity(40%–50%) and medium boundary layer heights(1200–1500 m), O3 production sensitivity occurred in the transitional region between volatile organic compounds(VOC) and nitrogen oxides(NOx) limitations,and the O3 concentration was the highest. The vertical profiles of O3 were also measured by a tethered balloon. The results showed that a large amount of O3 was stored in the residual layer, and the concentration was positively correlated with the O3 concentration measured the previous day. During the daytime of the following day, the contribution of O3 stored in the residual layer to the boundary layer reached 27%± 7% on average.

Characteristics of PM_(2.5) pollution in Beijing after the improvement of air quality

Following the implementation of the strictest clean air policies to date in Beijing,the physicochemical characteristics and sources of PM_(2.5) have changed over the past few years.To improve pollution reduction policies and subsequent air quality further,it is necessary to explore the changes in PM_(2.5) over time.In this study,over one year(2017-2018)field study based on filter sampling(TH-150C;Wuhan Tianhong,China)was conducted in Fengtai District,Beijing,revealed that the annual average PM_(2.5) concentration(64.8±43.1μg/m^3)was significantly lower than in previous years and the highest PM_(2.5) concentration occurred in spring(84.4±59.9μg/m^3).Secondary nitrate was the largest source and accounted for 25.7%of the measured PM_(2.5).Vehicular emission,the second largest source(17.6%),deserves more attention when considering the increase in the number of motor vehicles and its contribution to gaseous pollutants.In addition,the contribution from coal combustion to PM_(2.5) decreased significantly.During weekends,the contribution from EC and NO3−increased whereas the contributions from SO4^2−,OM,and trace elements decreased,compared with weekdays.During the period of residential heating,PM_(2.5) mass decreased by 23.1%,compared with non-heating period,while the contributions from coal combustion and vehicular emission,and related species increased.With the aggravation of pollution,the contribution of vehicular emission and secondary sulfate increased and then decreased,while the contribution of NO3−and secondary nitrate continued to increase,and accounted for 34.0%and 57.5%of the PM_(2.5) during the heavily polluted days,respectively.

植物热激转录因子家族的研究进展

随着全球气候的不断变化,植物常遭受热胁迫、干旱胁迫、冷胁迫、盐碱胁迫等多种非生物胁迫。植物热激转录因子(Heat shock transcription factors,HSFs)作为植物体内广泛存在的一类转录因子,能够响应多种非生物胁迫。文中就HSFs的结构、信号调控机制以及其在主要植物拟南芥、番茄、水稻和大豆中的研究进行回顾和总结,以期为进一步阐明HSFs在逆境调控网络中的作用提供参考。

Significant contribution of spring northwest transport to volatile organic compounds in Beijing

High values of ozone(O_(3))occur frequently in the dry spring season;thus,understanding the evolution characteristics of volatile organic compounds(VOCs)in spring is of great significance for preventing O_(3)pollution.In this study,a total of 101 VOCs from April 16 to May 21,2019,were quantified using an online gas chromatography mass spectrometer/flame ionization detector(GCMS/FID).The results indicated that the observed concentration of total VOCs(TVOCs)was 30.4±17.0 ppbv,and it was dominated by alkanes(44.3%),followed by oxygenated VOCs(OVOCs)(17.4%),halocarbons(12.7%),aromatics(9.5%),alkenes(8.2%),acetylene(5.3%)and carbon disulfide(2.5%).The average mixing ratio of VOCs showed obvious diurnal variation(high at night,low during daytime).We conducted a source apportionment study based on 32 major VOCs using positive matrix factorization(PMF),and coal+biomass burning(25.2%),diesel exhaust(16.0%),gasoline exhaust+evaporation(17.4%),secondary+long-lived species(16.7%),biogenic sources(4.3%),industrial emissions(9.3%)and solvent use(11.2%)were identified as major sources of VOCs.In addition to local emissions,most of the atmospheric VOCs were derived from long-distance air masses(65.7%),and the average mixing ratio of VOCs in the northwest direction was 29.4 ppbv.Combined with the results of the potential source contribution function(PSCF)indicate that research should focus on the local emissions of combustion,transportation sources and solvents usage to control atmospheric VOCs.Additionally,transmission of the northwest air mass is an important component that cannot be ignored during spring in Beijing.

Construction and Expression of a Single Chain Antibody Mimicing Human Ovarian Cancer Antigen CA125

One concept for immune therapy of cancer involves induction of antigen mimic antibodies to trigger the immune response against tumor cells. Anti-idiotypic antibodies directed against the antigen-binding site of antibodies specific for tumor antigen may functionally and even structurally mimic antigen and induce anti-anti-idiotypic immune response. Monoclonal antibody W J02 is one of such anti-idiotypic antibodies, which contains internal image of CA125. In order to improve the immunospecificity of mAb WJ02, we constructed a single chain of mAb WJ02 in Vl-linker-Vh orientation. The scFv-WJ02, could be expressed and secreted in the recombinant Pichia pastoris system. The secreted scFv protein with a molecular weight of 30 kD retained the biological activity of mAb WJ02, which was proved by a direct binding assay and inhibition experiment. Our results indicated that the scFv-WJ02 could be used as a possible tool for idiotypic therapy against ovarian cancer, which might enhance the possibility of eliminating nonspecific responses induced by mAb WJ02.

魔芋AaHSFB1基因及其启动子的克隆与功能分析

为了初步探究魔芋热激转录因子HSFB1基因及其启动子的功能,以白魔芋Amorphophallus albus为试材,利用同源克隆方法获得长度为1365 bp的AaHSFB1基因序列。qRT-PCR结果表明:AaHSFB1基因对热胁迫较敏感,在根中的表达量表现出先升后降的趋势,并在热处理1 h时表达丰度最高;在热处理12 h时,叶片中的表达量也达到最高,在整个热处理时段内球茎中的表达量变化不大;亚细胞定位结果显示AaHSFB1定位于细胞核内。再利用FPNI-PCR法通过三轮步移扩增得到1509bp的AaHSFB1启动子序列。生物信息学分析表明:AaHSFB1含有热胁迫响应元件HSE及多种与植物发育及逆境应答相关的顺式作用元件。为进一步分析AaHSFB1启动子的功能,构建融合表达载体prAaHSFB1::GUS,利用农杆菌介导法转入拟南芥,热处理后对转基因拟南芥进行GUS组织化学染色鉴定,结果显示其表达部位主要在叶中。因此推测AaHSFB1可能在白魔芋抗外界逆境特别是热胁迫中起重要作用。

Annual nonmethane hydrocarbon trends in Beijing from 2000 to 2019

High loads of ground-level ozone have occurred with the implementation of the Air Pollution Prevention and Control Action Plan.However,the long temporal variation in precursor nonmethane hydrocarbons(NMHCs)has rarely been studied.In this study,we examined the evolution of NMHCs in Beijing based on ambient measurements from 2000 to 2019.The results indicated that the annual variation of ambient NMHCs during 2000 and 2019 could be divided into two stages.The mixing ratios of NMHCs rapidly rose during 2000 and 2009(1.76 ppbv/year)but exhibited a downward trend from 2009 to 2019 at rate of 0.80 ppbv/yr.Moreover,the notable decrease in alkenes and aromatics after 2009 led to a sharp decrease in the propylene-equivalent concentration(PEC)(-0.80 ppbv/year).Implementation of emission reduction measures in Beijing have effectively reduced the contribution of vehicle-related sources,but the contribution of solvent usage and fuel consumption increased,which will become the focus of VOC control in Beijing in the future.