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An Invasive Succulent Plant (Kalanchoe daigremontiana) Influences Soil Carbon and Nitrogen Mineralization in a Neotropical Semiarid Zone

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Pedosphere 2018年第4期28卷 632-643页

作者： Ileana HERRERA Jose R. FERRER-PARIS Diana benzo Saul FLORES Belkis GARCIA Jafet M. NASSAR Ecuela de Ciencias Ambientales Universidad Espiritu Santo Guayaquil 091650 (Ecuador) Centro de Ecologla Instituto Venezolano de Investigaciones Cientificas (IVIC) Caracas 1020 (Venezuela) Centro de Estudios Botdnieos y Agroforestales Instituto Venezolano de Investigaeiones Cientificas Maracaibo 4005 (Venezuela)

It has long been recognized that plant invasions may alter carbon(C) and nitrogen(N) cycles, but the direction and magnitude of such alterations have been rarely quantified. In this study, we quantified the effects caused by the invasion of a noxious exotic plant,Kalanchoe daigremontiana(Crassulaceae), on C and N mineralization and enzymatic and microbial activities in the soil of a semiarid locality in Venezuela. We compared soil parameters associated with these processes(C and N mineralization time and the cumulative values, fluorescein diacetate hydrolytic activity, and activities of dehydrogenase, β-glucosidase, glucosaminidase, and urease) between invaded and adjacent non-invaded sites. In addition, correlations among these parameters and the soil physical-chemical properties were also examined to determine if a positive feedback exists between nutrient availability and K. daigremontiana invasion. Overall,our results showed that C mineralization and transformation of organic compounds to NH_4^+ were favored at sites colonized by ***. With this species, we found the highest cumulative amounts of NH_4^+-N and C and the lowest mineralization *** results could be explained by higher activities of urease and glucosaminidase in soils under the influence of K. *** addition, higher amounts of organic matter and moisture content in invaded soils might favor C and N mineralization. In conclusion,invasion of Neotropical semiarid zones by K. daigremontiana may influence the chemical and biological properties of the soils covered by this species, increasing nutrient bioavailability, which, in time, can facilitate the invasion process.

关键词：矿化作用土壤碳半干旱植物热带氮化学药品有机化合物

Metal-Free Arylsulfonyl Radical Triggered Cascade Cyclization of Phenyl-Linked 1,6-Enynes:Synthesis of 2,3-Dihydro-1H-indenes and 10a,11-Dihydro-10H-benzo[b]fluorines

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Chinese Journal of Chemistry 2022年第23期40卷 2756-2762页

作者： Lin-Ping Hu de-Run Zhang Xiao-Hong Huang Feng-Lin Liu Xia Li Ming-yu Teng Guo-Li Huang School of Chemistry and Chemical Engineering Yunnan Normal UniversityKunmingYunnan 650500China department of Library Yunnan Normal UniversityKunmingYunnan 650500China

Aryl sulfonyl radical triggered cascade cyclization of phenyl-linked 1,6-enynes for the synthesis of biologically important indenes containing alkenyl C—X bonds and 10a,11-dihydro-10H-benzo[b]fluorines is *** these radical cascade processes,three new chemical bonds,including C—S,C—C,and C—X bonds,and three C—C bonds are formed in one *** method is attractive and valuable due to its metal-free,mild reaction conditions,broad substrate scope and good functional group tolerance.

关键词： Radical reactions Cyclization Enynes Aryl sulfonyl Indenes

Application of 3A Zeolite Prepared from Venezuelan Kaolin for Removal of Pb (II) from Wastewater and Its determination by Flame Atomic Absorption Spectrometry

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American Journal of Analytical Chemistry 2013年第10期4卷 584-593页

作者： Wendy Rondón David Freire zul.y de benzo Angela B. Sifontes yorbin González Maribel Valero Joaquín L. Brito Laboratorio de Espectroscopia Molecular Facultad de Ciencias Universidad de Los Andes Mérida Venezuela Laboratorio de Fisicoquímica de Superficies Centro de Química Instituto Venezolano de Investigaciones Científicas IVIC Caracas Venezuela Laboratorio de Química Analítica Centro de Química Instituto Venezolano de Investigaciones Científicas IVIC Caracas Venezuela

This work consists in the use of a 3A zeolite (K-LTA) obtained by a process of exchange of sodium for potassium (4A zeolite), synthesized from Venezuelan kaolin for the removal of Pb (II) ions from aqueous solutions by batch process mode in order to consider its application in treating industrial wastewaters. The 3A zeolite was characterized for X-ray powder diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy dispersive X-ray microanalysis (SEM-EDX). The metal concentration in the equilibrium Ce (mg·L-1) after adsorption with 3A zeolite was analyzed using flame atomic absorption spectrometry (FAAS). The influences of the solution pH, contact time, metal initial concentration and adsorbent dosage have been studied. The retention of metal occurring at pH values around 6.5 and the adsorption equilibrium was obtained at 60 min. The equilibrium process was well described by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The Langmuir parameters qm (mg·g-1) and b (L·mg-1) (which are related to the sorption capacity and constant of sorption energy) obtained were 14.64 and 5.42 respectively. The Pb (II) experimental uptake was about 14.56 mg·g-1, a little smaller than the theoretical one given by Langmuir isotherm model. The regression parameters and correlation coefficients (R) indicate that the adsorption data for Pb (II) removal fit better the Langmuir isotherm model. Moreover, 0 1/n 1 (1/n is 0.13), indicating that adsorption of metal ions on the zeolite, is a favorable physical process. The application of removing of the metal lead from real samples was examined by industrial wastewater samples. For all samples, the percentage of recovery was found with accuracy of more than 98%. The present work suggests 3A zeolite used as a sorbent material with relatively low cost, obtained from Venezuelan raw material;it is a candidate for removal lead ion and probably other cationic heavy metal species

关键词： Adsorption Wastewater Lead (II) Ion Zeolite Langmuir Isotherm FAAS

benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole-porphyrin-based near-infrared dyes

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SmartMat 2021年第3期2卷 398-405页

作者： yi Liu Shaofei Wu Tullimilli y.Gopalakrishna Jishan Wu department of Chemistry National University of SingaporeSingaporeSingapore Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhouBinhai New CityChina

benzo[1,2-c;4,5-cʹ]bis[1,2,5]thiadiazole(BBT)has intrinsic diradical character and herein it is used to construct organic near-infrared(NIR)dyes together with the aromatic porphyrin *** BBT-porphyrin hybrid dyes 1-3 with different linkage modes are synthesized by Pd-catalyzed Sonogashira crosscoupling between meso-ethynylene porphyrin units and monobromo-/dibromo-BBT,or through unexpected homocoupling between the BBT *** all possess small open-shell diradical character and display intense NIR absorption in the range of 800-1000 *** also exhibit amphoteric redox ***-based diradicaloids are thus good candidates for organic NIR dyes.

关键词： benzo[1,2-c 4,5-c']bisthiadiazole diradical character near-infrared dye porphyrin

Convenient Synthesis of Substituted Quinoxalines and 2H-benzo[b][1,4]oxazines in Water

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Chemical Research in Chinese Universities 2009年第2期25卷 174-177页

作者： DING Chang-jiang WANG yan ZHANG Wei-wei LIU Li LIANG yong-jiu DONG de-wen College of Chemistry Jilin University Changchun 130012 P. R. China Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 P. R. China

A facile and convenient synthesis method has been developed for substituted quinoxalines and 2H-benzo[b][1,4]oxazines from the reactions of a-bromoketones with benzene-1,2-diamine and 2-aminophenol, respectively, whic... 详细信息

关键词： Quinoxaline Benzene-l,2-diamine 2-Aminophenol a-Bromoketone Water

The Novel benzo-15-Crown-5 with Palladium(II) Complex: [Na(B15CS)]_2,[Pd(SCN)_4]

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Chinese Chemical Letters 2000年第9期11卷 835-838页

作者： Lan ying ZHU Jian Min DOU ying LIU de Zhi SUN Pei Ju ZHENG Chen Xia DU yu ZHU department of Biology and Chemistry, Liaocheng Teacher’s University, Liaocheng 252000 Research Center of Analysis and Measurement, Fudan University, Shanghai 200433 Key department of Biology and Chemistry Liaocheng Teacher's University Liaocheng 252000 China Res. Ctr. of Anal. and Measurement Fudan University Shanghai 200433 China Key Laboratory of Applied Chemistry Zhengzhou University Zhengzhou 450052 China

A novel Pd(II) benzo-15-crown-5 complex [Na(B15CS)]_2[Pd(SCN)_4] has been isolated and characterized by IR and X-ray diffraction analysis. The crystal structure belongs to monoclinic, space group P2_1,/n with cell dimensions, a = l.0164(6), b = l.3743(3), c = l.4987(7) nm, β = 95.248(6) °, V = 2.0847 'nm_3, Z = 2, F(000) = 944, R = 0.053, Rw = 0.072. The compound consists of two [Na(B15CS)]+ complex canons and a [Pd(SCN)4_]^(2-) complex anion. Each sodium ion is coordinated by five crown ether oxygen atoms and one N atom from the SCN group of [Pd(SCN)_4]^(2-) to form stable neutral complex.

关键词： benzo-15-crown-5 crown ether crystal structure palladium complex.

Retinoid and Ethanol-Sensitive benzo(<i>α</i>)Pyrene Induction of Cytochrome P450 in Human Keratinocytes

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Journal of Cancer Therapy 2012年第6期3卷 1080-1085页

作者： John J. Wille Jong y. Park Bioderm Technologies Inc. Chesterfield USA Division of Cancer Prevention and Control Moffitt Cancer Center Tampa USA.

Polycyclic aromatic hydrocarbons (PAHs) induce cytochrome P-450 monoxygenase enzymes that catalyze the formation of DNA adducts. We investigated the effects benzo(α)pyrene (B[α]P) alone or in combination with ethanol on normal human keratinocyte (NHK) growth, induction of cytochrome P-4501A1 (CyP1A1), and modulation of these treatments by retinoic acid (RA) in a serum-free culture medium. Growth-arrested confluent NHK serum-free cultures were treated with B[α]P alone or in combination with ethanol and RA. The effects on CyP1A1 enzyme activity were investigated. B[α]P treatment alone was not toxic to post-confluent cells;sub-toxic ethanol stimulated cell growth regardless B[α]P treatment. No CyP1A1 activity was detected in control or ethanol-treated NHK cell cultures. B[α]P alone induced CyP1A1 activity, and B[α]P plus ethanol treatment further enhanced B[α]P-induced CyP1A1 activity. Pretreatment with all-trans-RA (t-RA) abolished ethanol enhancement of CyP1A1 activity. There is a synergistic action of ethanol in combination with PAH on induction of P-450 cytochrome enzymes. By contrast, RA reverses ethanol enhancement implying a role for retinoid therapy in counteracting the risk posed by combined alcohol and PAH exposure on epidermal cell carcinogenesis.

关键词： CyP1A1 Aryl Hydrocarbon Hydroxylase benzo(α)Pyrene Ethanol Keratinocytes Retinoids

A biomass-involved strategy for the synthesis of N-arylated dibenzo-[b,e][1,4]oxazepin-11（5H）-ones, acridones, 7,12-dihydrodi-benzo[b,e] [1,4]oxazocin-6H-ones and dibenzo[b,f]azepin-10（11H）-ones

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A biomass-involved strategy for the synthesis of N-arylated ...

Analytical determination of benzophenone-3 in Sunscreen Preparations Using Boron-Doped Diamond Electrodes

中国化学会第十届全国天然有机化学学术会议

作者： En-Sheng Zhang Tian-Long Xu de-Jian Wang yong Zou Guangzhou Institute of Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences School of Pharmaceutical Sciences Sun Yat-sen University

＜正＞Based on our well-established protocol for the preparation of N-aryl 2-aminophenols（1）from renewable nature product（-）-shikimic acid,an efficient method for the assembly of novel and diversified polycyclic nitrogen-containing heterocycles has been *** kinds of polycyclic nitrogen-containing heterocycles with six to eight-membered ring systems,including N-

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来源： cnki会议评论

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American Journal of Analytical Chemistry 2011年第3期2卷 383-391页

作者： Michelli Thomaz Laranjeira Fabio de Lima Silvio Cesar de Oliveira Valdir Souza Ferreira Robson Tadeu Soares de Oliveira 不详

A new electroanalytical procedure was developed for the determination of benzophenone-3 (benzo) in commercial sunscreen as the active ingredient. The procedure is based on the use of electrochemical methods as cyclic and square-wave voltammetry, with boron-doped diamond (BDD) electrodes. The reduction of benzo in Britton-Robinson buffer (0.1 mol●L–1) using this type of electrode gives rise to one irreversible peak in –1.30 V (versus Ag/AgCl) in presence of cationic surfactant cetyltrimethylammonium bromide (CTABr). The proposed electrochemical method was successfully applied to the analysis of commercially available pharmaceutical preparations.

关键词： Boron-Doped Diamond benzophenone-3 benzo and Square-Wave Voltammetry