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Characteristics of air particulate matter and their sources in urban and rural area of Beijing, China

Journal of Environmental Sciences 2000年第4期12卷 402-409页

作者： YANG Shao jin, DONG jin quan, cheng Bing ru (Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100080, China) Institute of High Energy Physics Chinese Academy of Sciences Beijing 100080 China

During October 1993 and March 1996, the samples of fine and coarse air particulate matter have been collected at representative urban and rural site of Beijing with the Gent Stacked Filter Unit Sampler. Instrumental neutron activation analysis (INAA) and proton induced X ray emission (PIXE) method were used to determine the elemental composition of the particulate matter. Average elemental concentrations and enrichment factors were calculated for the fine and coarse size fractions. Based on the particulate matter data obtained at urban and rural site together with the chemical constituents of the aerosol from the different sources are discussed. The results show that the relative particulate mass and elemental concentrations of crustal and pollutant elements in the air particulate matter collected over the urban are higher than rural and winter heating period are higher than in ordinary season. Beijing atmosphere is polluted by aerosols from regional and faraway sources. It was noticed that the toxic or harmful elements such as As, Sb, Pb, Cu, Ni, S and Zn were mainly enriched in fine particles with diameter less than 2 μm. A receptor model was used to assess the relative contribution of major air pollution sources at receptor sites in Beijing. Trace elements were used as the markers for the above assessment. Factor analysis method was used to identify possible emission sources of air particles. The major sources of dust soil, coal burning, motor vehicle emission, industry emission and refuse incineration were identified.

关键词： atmospheric particulate matter urban rural source aerosol

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quantum phase transition of the Jaynes-Cummings model

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 1-9页

作者： cheng Liu jin-Feng Huang Key Laboratory of Low-Dimensional quantum Structures and quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsInstitute of Interdisciplinary StudiesHunan Normal UniversityChangsha 410081China

Herein,we propose an experimentally feasible scheme to show the quantum phase transition of the Jaynes-Cummings(JC)model by modulating the transition frequency of a two-level system in a quantum Rabi model with strong *** tuning the modulation frequency and amplitude,the ratio of the effective coupling strength of the rotating terms to the effective cavity(atomic transition)frequency can enter the deep-strong coupling regime,while the counter-rotating terms can be ***,a deep-strong JC model is *** ratio of the coupling strength to resonance frequencies in the deep-strong JC model is two orders of magnitude larger than the corresponding ratio in the original quantum Rabi *** scheme can be employed in atom-cavity resonance and off-resonance cases,and it is valid over a broad *** nonzero average cavity photons of the ground state indicate the emergence of a quantum phase ***,we demonstrate the dependence of the phase diagram on the atom-cavity detuning and modulation *** the parameters used in our scheme are within the reach of current experimental *** scheme provides a new mechanism for investigating the critical phenomena of finite-sized systems without requiring classical field limits,thereby opening a door for studying fundamental quantum phenomena occurring in the ultrastrong and even deep-strong coupling regimes.

关键词： Jaynes-Cummings model quantum phase transition frequency modulation

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Root-derived long-distance signals trigger ABA synthesis and enhance drought resistance in Arabidopsis

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Journal of Genetics and Genomics 2024年第7期51卷 749-761页

作者： Qian-Qian Liu jin-Qiu Xia Jie Wu Yi Han Gui-quan Zhang Ping-Xia Zhao cheng-Bin Xiang Division of Life Sciences and Medicine Division of Molecular&Cell BiophysicsHefei National Science Center for Interdisciplinary Sciences at the MicroscaleUniversity of Science and Technology of ChinaThe Innovation Academy of Seed DesignChinese Academy of SciencesHefeiAnhui 230027China College of Life Sciences Anhui Agricultural UniversityHefeiAnhui 230036China College of Agronomy South China Agricultural UniversityGuangzhouGuangdong 510642China School of Biology and Basic Medical Sciences Soochow UniversitySuzhouJiangsu 215123China

Vascular plants have evolved intricate long-distance signaling mechanisms to cope with environmental stress,with reactive oxygen species(ROS)emerging as pivotal systemic signals in plant stress ***,the exact role of ROS as root-to-shoot signals in the drought response has not been *** this study,we reveal that compared with wild-type plants,ferric reductase defective 3(frd3)mutants exhibit enhanced drought resistance concomitant with elevated NINE-CIS-EPOXYCAROTENOID DIOXYGENASE 3(NCED3)transcript levels and abscisic acid(ABA)contents in leaves as well as increased hydrogen peroxide(H_(2)O_(2))levels in roots and *** experiments distinctly illustrate that drought resistance can be conferred by the frd3 rootstock regardless of the scion genotype,indicating that long-distance signals originating from frd3 roots promote an increase in ABA levels in ***,the drought resistance conferred by the frd3 mutant rootstock is weakened by the CAT2-overexpressing scion,suggesting that H_(2)O_(2)may be involved in long-distance ***,the results of comparative transcriptome and proteome analyses support the drought resistance phenotype of the frd3 *** together,our findings substantiate the notion that frd3 root-derived long-distance signals trigger ABA synthesis in leaves and enhance drought resistance,providing new evidence for root-to-shoot long-distance signaling in the drought response of plants.

关键词： frd3 Drought resistance Root-to-shoot long-distance signals Reactive oxygen species(ROS) H_(2)O_(2) Iron ABA

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Breast Cancer Resistance Protein Expression and 5-Fluorouracil Resistance

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Biomedical and Environmental Sciences 2008年第4期21卷 290-295页

作者： JIAN-HUI YUAN jin-quan cheng LONG-YUAN JIANG WEI-DONG JI LIANG-FENG GUO JIAN-JUN LIU XING-YUN XU jinG-SONG HE XIAN-MING WANG ZHI-XIONG ZHUANG Faculty of Preventive Medicine School of Public Health Sun Yat-Sen University Guangzhou 510080Guangdong China Toxicology Laboratory Municipal Center for Disease Control and PreventionShenzhen 518020 Guangdong China Department of Emergency The Second Affiliated Hospital of Sun Yat-Sen University Guangzhou 510120 Guangdong China Department of General Surgery Shenzhen Second People＇s Hospital Shenzhen 518035 Guangdong China

Objective To filtrate breast cancer resistance protein （BCRP）-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance. Methods MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography （HPLC） assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry （IHC） were employed to investigate the BCRP expression in breast cancer tissue specimens. Results MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil （5-Fu）（P〈0.05, n=3） in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP （t=-0.897, P〈0.05, n=3）. A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index （RI） of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance （R2=0.8124, P〈0.01）. Conclusion Resistance to 5-Fu can be mediated by BCRR Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression.

关键词： Breast cancer resistance protein 5-fluorouracil Breast cancer Resistance Chemotherapy

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Effect of FeSi additive in dual-chamber sample cup on thermal analysis characteristic values and vermiculating rate of compacted graphite iron

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China Foundry 2024年第1期21卷 91-100页

作者： De-quan Shi Ze-yu Liu Gui-li Gao Yi-cheng Feng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China School of Materials Science and Chemical Engineering Harbin University of Science&TechnologyHarbin 150040China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China

Thermal analysis plays a key role in the online inspection of molten iron *** solidification process of molten iron can be reflected by thermal analysis curves,and silicon is one of important elements affecting the solidification of molten *** this study,FeSi75 was added in one chamber of the dual-chamber sample cup,and the influences of FeSi75 additive on the characteristic values of thermal analysis curves and vermiculating rate were *** results show that with the increase of FeSi75,the start temperature of austenite formation TALfirstly decreases and then increases,but the start temperature of eutectic growth TSEF,the lowest eutectic temperature TEU,temperature at maximum eutectic reaction rate TEM,and highest eutectic temperature TERkeep always an *** temperature at final solidification point TEShas little *** FeSi75 additive has different influences on the vermiculating rate of molten iron with different vermiculation,and the vermiculating rate increases for lower vermiculation molten iron while decreases for higher *** to the thermal analysis curves obtained by a dual-chamber sample cup with 0.30wt.%FeSi75 additive in one chamber,the vermiculating rate of molten iron can be evaluated by comparing the characteristic values of these *** time differenceΔtERcorresponding to the highest eutectic temperature TERhas a closer relationship with the vermiculating rate,and a parabolic regression curve between the time differenceΔtERand vermiculating rateηhas been obtained within the range of 65%to 95%,which is suitable for the qualified melt.

关键词： FeSi75 additive characteristic value vermiculating rate thermal analysis compacted graphite iron

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Controllable CPL response driven by achiral UV-photosensitive dichroic dye through cholesteric liquid crystals

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Science China Chemistry 2024年第4期67卷 1250-1255页

作者： Yihan Chen Yang Li Hang Li Lulu Li Yiwu quan Yixiang cheng State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Key Laboratory of High-Performance Polymer Material and Technology of Ministry of Education School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

Versatile stimuli-responsive circularly polarized luminescent(CPL)materials have potential applications in information storage,security encryption,and intelligent *** this study,the Z/E isomerization of ultraviolet(UV)-photosensitive achiralα-cyanostilbene derivative was used as an achiral dichroic dye(Switch)to drive the controllable CPL-active response in cholesteric liquid crystals(CLCs).Under irradiation by 365 nm UV light,the resulting CLCs-Z-Switch underwent a Z-to-E configuration isomerization as CLCs-E-Switch,accompanied by a decrease in its dichroic order parameter(SFvalue)from 0.15to *** the quantum yield(QY)of CLCs-E-Switch increased from 8.1%(CLCs-Z-Switch)to 16.8%,the corresponding glumvalues of CPL emission decreased from+0.55/-0.57 to+0.37/-0.39 due to a decrease in the order of helical arrangement of E-Switch in E7 *** study enables photosensitive CLCs-Switch to be applied for optical information storage devices.

关键词： circularly polarized luminescent photosensitive dichroic dye cholesteric liquid crystals chiral induction

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5S-Heudelotinone alleviates experimental colitis by shaping the immune system and enhancing the intestinal barrier in a gut microbiota-dependent manner

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Acta Pharmaceutica Sinica B 2024年第5期14卷 2153-2176页

作者： Qing Meng Jianshuang Guo Ke Lv Yang Liu jin Zhang Mingyue Li Xirui cheng Shenghua Chen Xiaoguang Huo quan Zhang Yue Chen jing Li State Key Laboratory of Medicinal Chemical Biology College of PharmacyNankai UniversityTianjin 300353China College of Chemistry and Frontiers Science Center for New Organic Matter Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China Accendatech Company Ltd.Tianjin 300193China

Aberrant changes in the gut microbiota are implicated in many diseases,including inflammatory bowel disease(IBD).Gut microbes produce diverse metabolites that can shape the immune system and impact the intestinal barrier integrity,indicating that microbe-mediated modulation may be a promising strategy for preventing and treating *** fecal microbiota transplantation and probiotic supplementation are well-established IBD therapies,novel chemical agents that are safe and exert strong effects on the gut microbiota are urgently ***,we report the total synthesis of heudelotinone and the discovery of 5S-heudelotinone(an enantiomer)as a potent agent against experimental colitis that acts by modulating the gut microbiota.5S-Heudelotinone alters the diversity and composition of the gut microbiota and increases the concentration of short-chain fatty acids(SCFAs);thus,it regulates the intestinal immune system by reducing proinflammatory immune cell numbers,and maintains intestinal mucosal integrity by modulating tight junctions(TJs).Moreover,5S-heudelotinone(2)ameliorates colitis-associated colorectal cancer(CAC)in an azoxymethane(AOM)/dextran sulfate sodium(DSS)-induced in situ carcinoma ***,these findings reveal the potential of a novel natural product,namely,5S-heudelotinone,to control intestinal inflammation and highlight that this product is a safe and effective candidate for the treatment of IBD and CAC.

关键词： 5S-heudelotinone Total synthesis Inflammatory bowel disease Gut microbiota Short-chain fatty acids Immune system Intestinal barrier Drug discovery

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Pt nanoclusters modified porous g-C_(3)N_(4)nanosheets to significantly enhance hydrogen production by photocatalytic water reforming of methanol

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Chinese Journal of Chemical Engineering 2024年第2期66卷 40-50页

作者： Yi-Fei Liang jin-Rong Lu Shang-Kun Tian Wen-quan Cui Li Liu Hebei Provincial Key Laboratory of Environmental Photocatalytic and Electrocatalytic Materials College of Chemical EngineeringNorth China University of Science and TechnologyTangshan 063210China

For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild *** attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of *** improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced *** catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes *** addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and *** study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.

关键词： Water reforming of methanol Photocatalysis g-C_(3)N_(4) Pt nanoclusters Hydrogen production

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Oxidation behavior of low-grade vanadiferous titanomagnetite concentrate with high titanium

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Journal of Iron and Steel Research International 2024年第2期31卷 329-341页

作者： jin-sheng Liu Zhen-xing Xing Gong-jin cheng Xue-yong Ding Xiang-xin Xue School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina Liaoning Key Laboratory of Recycling Science for Metallurgical Resources Shenyang110819LiaoningChina Innovation Research Institute of Vanadium and Titanium Resource Industry Technology Northeastern UniversityShenyang110819LiaoningChina

In order to clarify the oxidation mechanisms and make better use of the low-grade vanadiferous titanomagnetite concentrate with high titanium(LVTC),the oxidation behavior of LVTC was *** results showed that oxidation degree was achieved within 90 min when temperature was not lower than 700°C,and the main phases of the oxidized LVTC consisted of Fe9TiO15,Fe2O3,CaSiTiO5 and a small amount of *** temperature is favorable to the formation of *** surface of LVTC gradually becomes rough,with fine particles of needle-like and granular shape appearing on the surface,which finally turn from laminar to creamy,spread out,and are interspersed with many tiny *** phase oxidation paths in LVTC were as follows:(1)Fe2.75Ti0.25O4→Fe9TiO15+Fe2O3;(2)Fe2.75Ti0.25O4→Fe2O3+FeTiO3→Fe2TiO5;(3)FeTiO3→Fe2O3+Fe2Ti3O9→*** is predominantly mesoporous whether oxidized or not,with the pores mainly distributed in the range of 2–40 nm,and the specific surface area of LVTC decreases significantly with increasing temperature.

关键词： Low-grade vanadiferous titanomagnetite concentrate Oxidation degree Phase transformation Micromorphology Oxidation path Pore structure

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Alterations in the gut microbiome after transjugular intrahepatic portosystemic shunt in patients with hepatitis B virus-related portal hypertension

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World Journal of Gastroenterology 2024年第31期30卷 3668-3679页

作者： Hong-Wei Zhao jin-Long Zhang Fu-quan Liu Zhen-Dong Yue Lei Wang Yu Zhang cheng-Bin Dong Zhen-Chang Wang Department of Radiology Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Department of Radiology Beijing Tongren HospitalCapital Medical UniversityBeijing 100730China Department of Interventional Radiology Beijing Shijitan HospitalCapital Medical UniversityBeijing 100038China

BACKGROUND Gut microbiota(GM)affects the progression and response to treatment in liver *** GM composition is diverse and associated with different etiologies of liver ***,alterations in GM alterations are observed in patients with portal hypertension(PH)secondary to cirrhosis,with hepatitis B virus(HBV)infection being a major cause of cirrhosis in ***,understanding the role of GM alterations in patients with HBV infection-related PH is *** To evaluate GM alterations in patients with HBV-related PH after transjugular intrahepatic portosystemic shunt(TIPS)*** This was a prospective,observational clinical *** were 30 patients(with a 100%technical success rate)recruited in the present *** with esophagogastric variceal bleeding due to HBV infection-associated PH who underwent TIPS were *** samples were obtained before and one month after TIPS treatment,and GM was analyzed using 16S ribosomal RNA amplicon *** One month after TIPS placement,8 patients developed hepatic encephalopathy(HE)and were assigned to the HE group;the other 22 patients were assigned to the non-HE *** was no substantial disparity in the abundance of GM at the phylum level between the two groups,regardless of TIPS treatment(all,P>0.05).However,following TIPS placement,the following results were observed:(1)The abundance of Haemophilus and Eggerthella increased,whereas that of Anaerostipes,Dialister,Butyricicoccus,and Oscillospira declined in the HE group;(2)The richness of Eggerthella,Streptococcus,and Bilophila increased,whereas that of Roseburia and Ruminococcus decreased in the non-HE group;and(3)Members from the pathogenic genus Morganella appeared in the HE group but not in the non-HE *** Intestinal microbiota-related synergism may predict the risk of HE following TIPS placement in patients with HBVrelated *** microbiome therapies may be useful for preventing and trea

关键词： Transjugular intrahepatic portosystemic shunt Hepatic encephalopathy Gut microbiota Hepatitis B virus Portal hypertension

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