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Biomedical and Environmental Sciences 2013年第2期26卷 138-147页

作者： SONG er Qun MA Xiao Yan TIAN Xing Guo LIU Jing LIU Li Chao DONG Hui SONG Yang Key Laboratory of Luminescence and Real-Time Analysis Ministry of EducationCollege of PharmaceuticalSciencesSouthwest University

Objective To compare the nature of the metabolites formed from the phase I metabolism （hydroxylation and oxidation） and phase II metabolism （glutathionyl conjugation） of PCBs that have different chlorine substitution patterns. To discuss the structure-activity relationships and metabolic mechanisms of PCBs. Methods 4-CI-biphenyl （PCB3）, 4,4＇-CI-biphenyl （PCB15）, 3,4,3＇,4＇-Cl-biphenyl （PCB77） were used for in vitro metabolic study. LC/MS and UV-Vis studies were performed for metabolites identification. Results The cytochrome P-450 catalyzed hydroxylation rate decreased as the number of chlorine substitutions increased. In this reaction, PCB3 was fully metabolized, approximately half of the PCB15 was metabolized and PCB77 was not metabolized at all. The oxidation rate of PCB15-HQ was higher than that of PCB3-HO. under various oxidation conditions. The LC/MS and UV-Vis data suggest that in the conjugation reaction of PCB15-Q and GSH, the michael addition reaction occurs preferentially over the displacement reaction. Conclusion The metabolic profiles of polychlorinated biphenyls （PCBs） are dramatically affected by chlorine substitution patterns. It is suggested that the metabolic profiles of PCBs are related to their chlorine substitution patterns, which may have implications for the toxicity of PCB exposure.

关键词： PCB metabolism Cytochrome P450 Glutathione Quinone Hydroquinone

Glycosylation of N-hydroxy-pipecolic acid equilibrates between systemic acquired resistance response and plant growth

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Molecular Plant 2021年第3期14卷 440-455页

作者： Jianghua Cai Adam Jozwiak Lara Holoidovsky michael MMeijler Sagit Meir Ilana Rogachev Asaph Aharoni Department of Plant and Environmental Sciences Weizmann Institute of ScienceRehovot 761001Israel Department of Chemistry and the National Institute for Biotechnology in the Negev Ben-Gurion University of the NegevBe’er-Sheva 8410501Israel

N-hydroxy-pipecolic acid(NHP)activates plant systemic acquired resistance(SAR).Enhanced defense responses are typically accompanied by deficiency in plant development and *** of extensive studies on SAR induction,the effects of NHPmetabolismon plant growth remain largely *** this study,we discovered that NHP glycosylation is a critical factor that fine-tunes the tradeoff between SAR defense and plant *** demonstrated that a UDP-glycosyltransferase(UGT76B1)forming NHP glycoside(NHPG)controls the NHP to NHPG ***,the ugt76b1 mutant exhibits enhanced SAR response and an inhibitory effect on plant growth,while UGT76B1 overexpression attenuates SAR response,promotes growth,and delays senescence,indicating that NHP levels are dependent on UGT76B1 function in the course of ***,our results suggested that,upon pathogen attack,UGT76B1-mediated NHP glycosylation forms a‘‘hand brake’’on NHP accumulation by attenuating the positive regulation of NHP biosynthetic pathway genes,highlighting the complexity of SAR-associated *** addition,we showed that UGT76B1-mediated NHP glycosylation in the local site is important for fine-tuning SAR *** results implicate that engineering plant immunity through manipulating the NHP/NHPG ratio is a promising method to balance growth and defense response in crops.

关键词： N-hydroxy-pipecolic acid N-hydroxy-pipecolic acid glycoside UDP-glycosyltransferase glycosylation systemic acquired resistance plant growth

Reinvigorating the Wiener-Hopf technique in the pursuit of understanding processes and materials

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National Science Review 2021年第2期8卷 11-13页

作者： David Abrahams Xun Huang Anastasia Kisil Gennady Mishuris michael Nieves Sergei Rogosin Ilya Spitkovsky IsaacNewtonInstituteforMathematicalSciences CollegeofEngineering PekingUniversity DepartmentofMathematics UniversityofManchester DepartmentofMathematics AberystwythUniversity SchoolofComputingandMathematics KeeleUniversity FacultyofEconomics BelarusianStateUniversity ScienceandMathematics NewYorkUniversityAbuDhabi

The Wiener-Hopf(WH) method was created in 1931, by Norbert Wiener and Eberhard Hopf, to deliver exact solutions to integral equations with convolutiontype kernels on a half-line. It appears that this problem is closely related to that posed by Riemann in 1857 on the problem concerning the construction of a Fuchsian system of differential equations with given singular points and a prescribed monodromy group. This later became known as the 21 st Hilbert problem. The WH method is a powerful and long-standing tool that served as a catalyst in broadening the applicability of Fourier analysis, owing to the essential characteristics of analytic functions. Employing the Fourier transform(FT) to the integral equation leads to a RiemannHilbert(RH) problem on the real axis:

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A Preliminary Study on Anti-Colorectal Cancer Effect and Molecular Mechanism of Aegiceras Corniculatum Extract

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World Journal of Traditional Chinese Medicine 2023年第4期9卷 404-414页

作者： De‑Chao Tan Xiao‑Tao Hou Hua Luo Yi‑Wei Chen Zheng‑Cai Du Jin‑Ling Xie Lin‑Yao Wei Chi-Teng Vong Xiao‑Yan Wen er‑Wei Hao Jia‑Gang Deng Guangxi Key Laboratory of Efficacy Study on Chinese Materia Medica Guangxi University of Chinese MedicineNanningChina Guangxi Collaborative Innovation Center of Research on Functional Ingredients of Agricultural Residues NanningChina Institute of Chinese Medical Sciences State Key Laboratory of Quality Research in Chinese MedicineUniversity of MacaoMacaoChina Sino‑Canada Joint Zebrafish Lab for Chinese Herbal Drug Screening Guangxi University of Chinese MedicineNanningChina Zebrafish Center for Advanced Drug Discovery Keenan Research Center for Biomedical ScienceLi Ka Shing Knowledge InstituteSt.Michael’s HospitalTorontoOntarioCanada

Objective:To study the inhibitory effects on colorectal cancer(CRC)and the underlying mechanism of the petroleum ether extract of Aegiceras corniculatum leaves(PACL).Materials and Methods:The effect of PACL on the proliferation of CRC cell lines DLD-1,HT-29,and SW480was measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay and colony-forming *** then,a wound-healing assay was used to measure the migration ability of three CRC *** cell cycle and apoptosis of three CRC cells were measured by PI/RNase staining and annexin V-FITC/double staining,respectively,and the intrinsic apoptosis pathway was studied by the Western *** anti-CRC effect of PACL in vivo was evaluated by HT-29 xenograft zebrafish ***:PACL inhibited cell viability and proliferation in DLD-1,HT-29,and SW480 cells in a dose-and time-dependent *** can inhibit cell migration in DLD-1and SW480 cells but not in the less mobile phenotype cell *** treatment resulted in cell cycle arrest of DLD-1 and HT-29 cells in the G2/M ***,PACL can induce apoptosis in all three CRC cells,which may be achieved by regulating the intrinsic apoptosis pathway mediated by mitochondria and the endoplasmic ***,the tumor sizes were decreased after treatment with PACL and PACL combined with fluorouracil in HT-29 xenograft zebrafish ***:These findings suggested that PACL may exert its anti-CRC effect by inducing apoptosis through the intrinsic apoptosis pathway and show a significant anti-CRC effect in vitro and in vivo,so it might be potentially developed as an anti-CRC agent.

关键词： Aegiceras corniculatum apoptosis cell cycle colorectal cancer zebrafish xenograft

Understanding the sources and composition of the incremental excess of fine particles across multiple sampling locations in one air shed

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Journal of Environmental Sciences 2014年第4期26卷 818-826页

作者： Jerome E.McGinnis Jongbae Heo michael R.Olson Andrew P.Rutter James J.Schauer University of Wisconsin-Madison Environmental Chemistry and Technology Program Wisconsin State Laboratory of Hygiene

Well-designed health studies and the development of effective regulatory policies need to rely on an understanding of the incremental differences in particulate matter concentrations and their sources. Although only a limited number of studies have been conducted to examine spatial differences in sources to particulate matter within an air shed, routine monitoring data can be used to better understand these differences. Measurements from the US EPA Chemical Speciation Network （CSN） collected between 2002-2008 were analyzed to demonstrate the utility of regulatory data across three sites located within 100 km of each other. Trends in concentrations, source contribution, and incremental excesses across three sites were investigated using the Positive Matrix Factorization model. Similar yearly trends in chemical composition were observed across all sites, however, excesses of organic matter and elemental carbon were observed in the urban center that originated from local emissions of mobile sources and biomass buming. Secondary sulfate and secondary nitrate constituted over half of the PM2.5 with no spatial differences observed across sites. For these components, the excess of emissions from industrial sources could be directly quantified. This study demonstrates that CSN data from multiple sites can be successfully used to derive consistent source profiles and source contributions for regional pollution, and that CSN data can be used to quantify incremental differences in source contributions of across these sites. The analysis strategy can be used in other regions of the world to take advantage of existing ambient particulate matter monitoring data to better the understanding of spatial differences in source contributions within a given air shed.

关键词： CSN Incremental Excess PMFPM2.5

Transcriptional down regulation of hTerT and senescence induction in HepG2 cells by chelidonine

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World Journal of Gastroenterology 2009年第29期15卷 3603-3610页

作者： Sakineh Kazemi Noureini michael Wink Department of Biology Faculty of Basic Science Tarbiat Moallem University of Sabzevar Sabzevar Iran Department of Biology Institute of Pharmacy and Molecular Biotechnology Heidelberg University INF 364 69120 Heidelberg Germany

AIM： To investigate the potential effects of chelidonine, the main alkaloid of Chelidonium majus, on telomerase activity and its regulation in HepG2 cells. METHODS： Cytotoxicity of chelidonine for HepG2 cells was determined by neutral red assay. A modified polymerase chain reaction （PCR）-based telomerase repeat amplification protocol was used to estimate relative telomerase activity in chelidonine-treated cells in comparison with the untreated control cells. Relative expression level of the catalytic subunit of telomerase （hTerT） gene and P-glycoprotein （pgp） were estimated using semi-quantitative real-time reverse transcription-PCR （RT-PCR）. Cell senescence in treated cells was demonstrated using a 13-galactosidase test. RESULTS： Cytotoxicity of chelidonine in HepG2 cells was not dose-dependent and tended to reach plateau immediately after the living cells were reduced in number to slightly higher than 50%. However, 12 μmol/L concentration of chelidonine was considered as LD50, where the maximal attainable effects were realized. Real-time RT-PCR data showed that the expression of pgp increased three-fold in chelidonine treated HepG2 cells in comparison with the untreated controls. MoP phologically, treated HepG2 cells showed apoptotic features after 24 h and a small fraction of cells appeared with single blister cell death. The relative expression level of Bcl-2 dropped to less than 50% of control cells at a sub-apoptotic concentration of chelidonine and subsequently increased to higher than 120% at LD50. Telomerase activity was reduced considerably after administration of very low doses of chelidonine, whereas higher concentrations of chelidonine did not remarkably enhance the effect. Real-time RT-PCR experiments indicated a drastic decrease in expression level of hTerT subunit of telomerase under treatment with chelidonine. Repeated treatment of cells with very low doses of chelidonine caused a decline in growth rate by 4 wk and many of the cells appeared to be a

关键词： Chelidonine Telomerase Inhibition Apoptosis Senescence

Direct measurement of the break-out ^(19)F(p,γ)^(20)Ne reaction in the China Jinping underground laboratory(CJPL)

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Nuclear Science and Techniques 2024年第8期35卷 142-152页

作者： Yin‑Ji Chen Hao Zhang Li‑Yong Zhang Jian‑Jun He Richard James deBoer michael Wiescher Alexander Heger David Kahl Jun Su Daniel Odell Xin‑Yue Li Jian‑Guo Wang Long Zhang Fu‑Qiang Cao Zhi‑Cheng Zhang Xin‑Zhi Jiang Luo‑Huan Wang Zi‑Ming Li Lu‑Yang Song Liang‑Ting Sun Qi Wu Jia‑Qing Li Bao‑Qun Cui Li‑Hua Chen Rui‑Gang Ma er‑Tao Li Gang Lian Yao‑De Sheng Zhi‑Hong Li Bing Guo Wei‑Ping Liu Key Laboratory of Beam Technology of the Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Department of Physics and Astronomy The Joint Institute for Nuclear AstrophysicsUniversity of Notre DameNotre DameIN 46556USA School of Physics and Astronomy Monash UniversityClaytonVIC 3800Australia Facility for Rare Isotope Beams Michigan State UniversityEast LansingMI 48824USA Institute of Nuclear and Particle Physics and Department of Physics and Astronomy Ohio UniversityAthensOH 45701USA Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China China Institute of Atomic Energy Beijing 102413China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China College of Science Southern University of Science and TechnologyShenzhen 518055China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China Key Laboratory of Nuclear Physics and Ion‑Beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China School of Mathematics and Physics Handan UniversityHandan 056005China

Calcium production and the stellar evolution of first-generation stars remain fascinating mysteries in *** one possible nucleosynthesis scenario,break-out from the hot carbon–nitrogen–oxygen(HCNO)cycle was thought to be the source of the calcium observed in these oldest ***,according to the stellar modeling,a nearly tenfold increase in the thermonuclear rate ratio of the break-out ^(19)F(p,γ)^(20) Ne reaction with respect to the competing ^(19)F(p,α)^(16) O back-processing reaction is required to reproduce the observed calcium *** performed a direct measurement of this break-out reaction at the China Jinping underground *** measurement was performed down to the low-energy limit of E_(c.m.)=186 keV in the center-of-mass *** key resonance was observed at 225.2 keV for the first *** a temperature of approximately 0.1 GK,this new resonance enhanced the thermonuclear ^(19)F(p,γ)^(20) Ne rate by up to a factor of≈7.4,compared with the previously recommended NACRE *** is of particular interest to the study of the evolution of the first stars and implies a stronger breakdown in their“warm”CNO cycle through the ^(19)F(p,γ)^(20) Ne reaction than previously *** break-out resulted in the production of the calcium observed in the oldest stars,enhancing our understanding of the evolution of the first stars.

关键词： Nuclear astrophysics First stars Abundance of calcium Reaction cross section Reaction rate China Jinping underground laboratory(CJPL) JUNA

Arabidopsis HIPP proteins regulate endoplasmic reticulum-associated degradation of CKX proteins and cytokinin responses.

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Molecular Plant 2021年第11期14卷 1918-1934页

作者： Tianqi Guo Henriette Weber michael C.E.Niemann Lisa Theisl Georgeta Leonte Ondrej Novak Tomas Werner Institute of Biology/Applied Genetics Dahlem Centre of Plant Sciences(DCPS)Freie Universitat BerlinAlbrecht-Thaer-Weg 614195 BerlinGermany Guangdong Provincial Key Laboratory of Conservation and Precision Utilization of Characteristic Agricultural Resources in Mountainous Areas School of Life Science of Jiaying University514015 Mei ZhouChina lnstitute of Biology University of GrazSchubertstraβe 518010 GrazAustria Laboratory of Growth Regulators Centre of the Region Hana for Biotechnological and Agricultural ResearchPalacky University and Institute of Experimental Botany ASCR78371 OlomoucCzech Republic

Eukaryotic organisms are equipped with quality-control mechanisms that survey protein folding in the endoplasmic reticulum (er) and remove non-native proteins by er-associated degradation (erAD). Recent research has shown that cytokinin-degrading CKX proteins are subjected to erAD during plant development. The mechanisms of plant erAD, including the export of substrate proteins from the er, are not fully understood and the molecular components involved in the erAD of CKX are unknown. We show that heavy metal-associated isoprenylated plant proteins (HIPP) interact specifically with CKX proteins synthesized in the er and processed by erAD. CKX-HIPP protein complexes were detected at the er as well as in the cytosol, suggesting that the complexes involve retrotranslocated CKX protein species. Altered CKX levels in HIPP-overexpressing and higher-order hipp mutant plants suggest that the studied HIPP proteins control the erAD of CKX. Deregulation of CKX proteins caused corresponding changes in the cytokinin signaling activity and triggered typical morphological cytokinin responses. Notably, transcriptional repression of HIPP genes by cytokinin indicates a feedback regulatory mechanism of cytokinin homeostasis and signaling responses. Moreover, the loss of HIPP genes constitutively activates the unfolded protein response and compromises the er stress tolerance, supporting the conclusion that HIPPs represent novel functional components of plant erAD.

关键词： Arabidopsis remove folding

Differences between amorphous indium oxide thin films

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Progress in Natural Science:Materials International 2013年第5期23卷 475-480页

作者： D.Bruce Buchholz Li Zeng michael J.Bedzyk Robert P.H.Chang Department of Materials Science and Engineering Northwestern University

A series of 60~nm thick indium oxide thin-films,all amorphous as determined by x-ray diffraction,were found to have physical and electrical properties that depended on the temperature of *** carrier mobility and flm conductivity decreased with decreasing deposition temperature;the best electrical properties of high mobility and conductivity were observed at a deposition temperature just below the temperature at which crystalline films *** density of the flm also decreased with deposition temperature from 7.2g/cm3 at+50℃ to 5.3g/cm3 at 100℃.

关键词： Transparent conducting oxide Semiconductor Oxide Amorphous Deposition temperature

Enhancing the soil and water assessment tool model for simulating N_(2)O emissions of three agricultural systems

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Ecosystem Health and Sustainability 2017年第2期3卷 17-29页

作者： Qichun Yang Xuesong Zhang michael Abraha Stephen Del Grosso G.P.Robertson Jiquan Chen Joint Global Change Research Institute Pacific Northwest National LaboratoryCollege ParkMaryland 20740 USA Great Lakes Bioenergy Research Center Michigan State UniversityEast LansingMichigan 48824 USA W.K.Kellogg Biological Station Michigan State UniversityHickory CornersMichigan 49060 USA Agricultural Research Service United States Department of AgricultureFort CollinsColorado 80526 USA Department of Plant Soiland Microbial SciencesMichigan State UniversityEast LansingMichigan 48824 USA Department of Geography Environmentand Spatial SciencesMichigan State UniversityEast LansingMichigan 48824 USA

Nitrous oxide(N_(2)O)is a potent greenhouse gas(GHG)contributing to global warming,with the agriculture sector as the major source of anthropogenic N_(2)O emissions due to excessive fertilizer *** is an urgent need to enhance regional-/watershed-scale models,such as Soil and Water Assessment Tool(SWAT),to credibly simulate N_(2)O emissions to improve assessment of environmental impacts of cropping ***,we integrated the DayCent model’s N_(2)O emission algorithms with the existing widely tested crop growth,hydrology,and nitrogen cycling algorithms in SWAT and evaluated this new tool for simulating N_(2)O emissions in three agricultural systems(i.e.,a continuous corn site,a switchgrass site,and a smooth brome grass site which was used as a reference site)located at the Great Lakes Bioenergy Research Center(GLBRC)scale-up fields in southwestern *** three systems represent different levels of management intensity,with corn,switchgrass,and smooth brome grass(reference site)receiving high,medium,and zero fertilizer application,*** indicate that the enhanced SWAT model with default parameterization reproduced well the relative magnitudes of N_(2)O emissions across the three sites,indicating the usefulness of the new tool(SWAT-N_(2)O)to estimate long-term N_(2)O emissions of diverse cropping ***,parameter calibration can significantly improve model simulations of seasonality of N_(2)O fluxes,and explained up to 22.5%-49.7%of the variability in field *** sensitivity analysis indicates that climate change(e.g.,changes in precipitation and temperature)influences N_(2)O emissions,highlighting the importance of optimizing crop management under a changing climate in order to achieve agricultural sustainability goals.

关键词： agriculture climate change greenhouse gas sensitivity analysis