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Zou SW, How CW, Chen JP. Photocatalytic Treatment of Wastewater Contaminated with Organic Waste and Copper Ions from the Semiconductor Industry. Ind Eng Chem Res 2007. [DOI: 10.1021/ie070478c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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127
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Shneor R, Monaghan P, Subedi R, Anderson BD, Aniol K, Annand J, Arrington J, Benaoum H, Benmokhtar F, Bertin P, Bertozzi W, Boeglin W, Chen JP, Choi S, Chudakov E, Cisbani E, Craver B, de Jager CW, Feuerbach RJ, Frullani S, Garibaldi F, Gayou O, Gilad S, Gilman R, Glamazdin O, Gomez J, Hansen JO, Higinbotham DW, Holmstrom T, Ibrahim H, Igarashi R, Jans E, Jiang X, Jiang Y, Kaufman L, Kelleher A, Kolarkar A, Kuchina E, Kumbartzki G, LeRose JJ, Lindgren R, Liyanage N, Margaziotis DJ, Markowitz P, Marrone S, Mazouz M, Meekins D, Michaels R, Moffit B, Nanda S, Perdrisat CF, Piasetzky E, Potokar M, Punjabi V, Qiang Y, Reinhold J, Reitz B, Ron G, Rosner G, Saha A, Sawatzky B, Shahinyan A, Sirca S, Slifer K, Solvignon P, Sulkosky V, Thompson N, Ulmer PE, Urciuoli GM, Voutier E, Wang K, Watson JW, Weinstein LB, Wojtsekhowski B, Wood S, Yao H, Zheng X, Zhu L. Investigation of proton-proton short-range correlations via the 12C(e,e'pp) reaction. PHYSICAL REVIEW LETTERS 2007; 99:072501. [PMID: 17930888 DOI: 10.1103/physrevlett.99.072501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Indexed: 05/25/2023]
Abstract
We investigated simultaneously the 12C(e,e'p) and 12C(e,e'pp) reactions at Q2=2 (GeV/c)2, xB=1.2, and in an (e, e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics, with a missing momentum greater than the Fermi momentum of nucleons in a nucleus and far from the delta excitation, short-range nucleon-nucleon correlations are predicted to dominate the reaction. For (9.5+/-2)% of the 12C(e,e'p) events, a recoiling partner proton was observed back-to-back to the 12C(e,e'p) missing-momentum vector, an experimental signature of correlations.
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Zhang HM, Yang J, Xin X, Chen JP, Adams MJ. Molecular characterization of the genome segments S4, S6 and S7 of rice gall dwarf virus. Arch Virol 2007; 152:1593-602. [PMID: 17558539 DOI: 10.1007/s00705-007-1004-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 05/04/2007] [Indexed: 10/23/2022]
Abstract
Rice gall dwarf virus (RGDV) is a member of the genus Phytoreovirus within the family Reovirdae. Its genome has 12 segments of double-stranded RNA (dsRNA), of which the nucleotide sequences of segments S4, S6, and S7 were determined, providing the first complete genome sequence of RGDV. Each of the segments S4, S6, and S7 contained conserved terminal sequences conforming to the RGDV consensus, 5'-GGXA ... UGAU-3' (X = U or C). Each segment had a single predicted open reading frame encoding proteins with calculated molecular weights of 79.8, 58.6, and 53.3 kDa. These proteins appeared to be homologous to those encoded by the corresponding segments of rice dwarf virus and wound tumor virus, the other known members of the same genus, having about 20-30% amino acid identity to them. It is therefore likely that RGDV S4 and S6 encode non-structural proteins and S7 an inner core protein. Probable homologies between the segments of all known phytoreoviruses are summarized. Beyond these similarities, the RGDV proteins displayed no significant similarity to any other reported viral proteins.
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Jiang X, Arrington J, Benmokhtar F, Camsonne A, Chen JP, Choi S, Chudakov E, Cusanno F, Deur A, Dutta D, Garibaldi F, Gaskell D, Gayou O, Gilman R, Glashauser C, Hamilton D, Hansen O, Higinbotham DW, Holt RJ, de Jager CW, Jones MK, Kaufman LJ, Kinney ER, Kramer K, Lagamba L, de Leo R, Lerose J, Lhuillier D, Lindgren R, Liyanage N, McCormick K, Meziani ZE, Michaels R, Moffit B, Monaghan P, Nanda S, Paschke KD, Perdrisat CF, Punjabi V, Qattan IA, Ransome RD, Reimer PE, Reitz B, Saha A, Schulte EC, Sheyor R, Slifer K, Solvignon P, Sulkosky V, Urciuoli GM, Voutier E, Wang K, Wijesooriya K, Wojtsekhowski B, Zhu L. Recoil-proton polarization in high-energy deuteron photodisintegration with circularly polarized photons. PHYSICAL REVIEW LETTERS 2007; 98:182302. [PMID: 17501566 DOI: 10.1103/physrevlett.98.182302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Indexed: 05/15/2023]
Abstract
We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.
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130
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Zhong B, Stanforth R, Wu S, Chen JP. Proton interaction in phosphate adsorption onto goethite. J Colloid Interface Sci 2007; 308:40-8. [PMID: 17254593 DOI: 10.1016/j.jcis.2006.12.055] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 12/07/2006] [Accepted: 12/18/2006] [Indexed: 11/22/2022]
Abstract
The adsorption of phosphate on goethite is generally modeled by assuming a simple ligand exchange reaction with surface hydroxyl groups. This study investigates the binding forms of phosphate on goethite by evaluating the proton interaction and surface charge change during phosphate adsorption. It is found that OH(-) release stoichiometry increases with phosphate coverage, which suggests that different mechanisms predominate at different phosphate loadings. It demonstrates that surface binding changes from monodentate complexation to bidentate complexation with increasing surface phosphate coverage. The net OH(-) release accompanying this transformation is best interpreted with a 2pK(a) multisite model.
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Wesselmann FR, Slifer K, Tajima S, Aghalaryan A, Ahmidouch A, Asaturyan R, Bloch F, Boeglin W, Bosted P, Carasco C, Carlini R, Cha J, Chen JP, Christy ME, Cole L, Coman L, Crabb D, Danagoulian S, Day D, Dunne J, Elaasar M, Ent R, Fenker H, Frlez E, Gan L, Gaskell D, Gomez J, Hu B, Jones MK, Jourdan J, Keith C, Keppel CE, Khandaker M, Klein A, Kramer L, Liang Y, Lichtenstadt J, Lindgren R, Mack D, McKee P, McNulty D, Meekins D, Mkrtchyan H, Nasseripour R, Niculescu I, Normand K, Norum B, Pocanic D, Prok Y, Raue B, Reinhold J, Roche J, Rohe D, Rondón OA, Savvinov N, Sawatzky B, Seely M, Sick I, Smith C, Smith G, Stepanyan S, Tang L, Testa G, Vulcan W, Wang K, Warren G, Wood S, Yan C, Yuan L, Yun J, Zeier M, Zhu H. Proton spin structure in the resonance region. PHYSICAL REVIEW LETTERS 2007; 98:132003. [PMID: 17501192 DOI: 10.1103/physrevlett.98.132003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Indexed: 05/15/2023]
Abstract
We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV<W<1.910 GeV) at an average four momentum transfer of Q2=1.3 GeV2. Using the Jefferson Lab polarized electron beam, a spectrometer, and a polarized solid target, we measured the asymmetries A|| and A(perpendicular) to high precision, and extracted the asymmetries A1 and A2, and the spin structure functions g1 and g2. We found a notably nonzero A(perpendicular), significant contributions from higher-twist effects, and only weak support for polarized quark-hadron duality.
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Sheng PX, Ting YP, Chen JP. Biosorption of Heavy Metal Ions (Pb, Cu, and Cd) from Aqueous Solutions by the Marine Alga Sargassum sp. in Single- and Multiple-Metal Systems. Ind Eng Chem Res 2007. [DOI: 10.1021/ie0615786] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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133
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Yang L, Wu S, Chen JP. Modification of Activated Carbon by Polyaniline for Enhanced Adsorption of Aqueous Arsenate. Ind Eng Chem Res 2007. [DOI: 10.1021/ie0611352] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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134
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Chen JP, Yang L. Study of a heavy metal biosorption onto raw and chemically modified Sargassum sp. via spectroscopic and modeling analysis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8906-14. [PMID: 17014134 DOI: 10.1021/la060770+] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In this study, raw and formaldehyde-modified Sargassum sp. are used for heavy metal removal. A series of experiments shows that the chemical modification by formaldehyde improves biosorption capacity by approximately 20%. Solution pH plays an important role in the metal uptake. According to X-ray photoelectron spectroscopic and Fourier transform infrared spectroscopic analysis, the possible organic functional groups in the metal binding include carboxyl, ether, alcoholic, hydroxyl, and amino functional groups. A new model that includes a series of coordination reactions among a generalized functional group, alkaline earth metal ions and heavy metal ions, is developed for simulation of biosorption process. The model well describes the single- and multiple-species metal biosorption process under different conditions such as pH. The biosorption of heavy metals is due to the ion exchange between the heavy metals and alkaline earth metals and their adsorption onto the free sites of the seaweeds. Slightly more than half of the metal uptake is due to ion exchange. The metal affinity for the functional groups follows a descending order of lead > copper > alkaline earth metal.
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135
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Zhu HQ, Chen JP, Yu SQ. Construction of an infectious cDNA clone of Ribgrass mosaic virus Shanghai isolate and its modification to express an epitope of Mycobacterium tuberculosis. Arch Virol 2006; 151:1853-61. [PMID: 16596330 DOI: 10.1007/s00705-006-0740-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2005] [Accepted: 02/05/2006] [Indexed: 01/01/2023]
Abstract
Infectious cDNA clones of the Shanghai isolate of Ribgrass mosaic virus (RMV) were produced by joining four overlapping cDNA fragments and also in a single step by long template PCR. After inoculation of Nicotiana glutinosa with either RNA transcripts or the cDNA under the control of the CaMV 35S promoter, plants developed typical symptoms, and viral coat protein could be detected in them by Western blot analysis. However, compared to plants inoculated with purified viral RNA, lesions were fewer and appeared more slowly. An epitope of the Mycobacterium tuberculosis 31-kDa protein was inserted at the C-terminus of the viral coat protein by PCR using two overlapping fragments. The modified clone was also infectious and the foreign epitope could be detected serologically in the electron microscope and by Western blot analysis. The results demonstrate the potential of RMV as a viral gene vector.
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Chen JP, Li J, Zhao SL, Tian JY, Ye F. [Establishment of Z-HL16C cell line.]. ZHONGHUA SHI YAN HE LIN CHUANG BING DU XUE ZA ZHI = ZHONGHUA SHIYAN HE LINCHUANG BINGDUXUE ZAZHI = CHINESE JOURNAL OF EXPERIMENTAL AND CLINICAL VIROLOGY 2006; 20:232-4. [PMID: 17086279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
BACKGROUND To establish and study the nature and the application of Z-HL16C cell line. METHODS The cell line was continuously passed, frozen stored and recovered. Its application was expanded and the cell type was identified. RESULTS The cell line had an epithelial-cell-like shape, the size appeared uniform, the cell boundary was distinct. It has been continuously passed, frozen stored and recovered for ten years. Its recovery rate was about 90%. It has been proved to be sensitive to the tested viruses which were enteroviruses (Polio, Cox, Echo), influenza viruses, parainfluenzaviruses, adenoviruses, measles virus. This cell line has been identified as a cancerization cell. CONCLUSION The cell line Z-HL16C has been stably established, it has a broad spectrum in sensitivity for culturing viruses.
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137
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Hua PY, Chen JP, Sun M, Liang B, Zhang SY, Wu DH. Characterization of microsatellite loci in fulvous fruit bat Rousettus leschenaulti. ACTA ACUST UNITED AC 2006; 6:939-941. [PMID: 32355465 PMCID: PMC7185440 DOI: 10.1111/j.1471-8286.2006.01407.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 03/02/2006] [Accepted: 03/25/2005] [Indexed: 12/01/2022]
Abstract
Rousettus leschenaulti is an abundant species in many countries of South‐East Asia, including south China. We isolated seven microsatellite loci in R. leschenaulti from genomic DNA enriched for CA repeats with the enriched library method. A total of 56 samples from a population in the Guangxi Province of China were tested with these microsatellite markers. The polymorphism ranged from seven to 16 alleles, and the observed heterozygosity was 84–94%. It is the first time microsatellite markers were characterized from R. leschenaulti, and these markers can be an important tool for analysing population structure and genotypic diversity.
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Abstract
BACKGROUND We have investigated the potential for using antisense technology as a means of delivering treatment for acute myeloblastic leukaemia (FAB-M2) by gene therapy. MATERIALS AND METHODS A test recombinant adenovirus vector was constructed containing human c-myc antisense fragments to study the effects of altering c-myc overexpression in the human HL-60 cell line. Control vector contained the human LacZ gene. Transfection efficiency in HL-60 cells was determined using control vector in the presence of protamine sulphate and multiplicity of infection of 100. Morphological and mechanistic changes were assessed using immunohistochemical analysis, flow cytometry and reverse transcription-polymerase chain reaction. RESULTS Transfection efficiency of control vector was 79.8% and morphological differences were observed after 72 h in culture. The rate of proliferation of HL-60 cells infected with test vector was inhibited by 73% compared with control following 6 days in culture. Normal terminal differentiation leading to apoptosis was only evident in test vector infected cells. Peak apoptosis (34.7%) was detected at day 6 and cell cycle arrest at days 2, 4 and 6. Expression of c-fos protein was significantly increased in test vector treated cells with a noticeable down-regulation of c-myc expression. CONCLUSIONS These data suggest that transfection of a human HL-60 cell line with vector containing c-myc antisense fragments could inhibit proliferation, but induce differentiation and apoptosis. Thus, we believe that further study of this construct is warranted as a potential gene therapy reagent for treatment of acute myeloblastic leukaemia.
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139
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Chen JP, Yang L. Chemical Modification ofSargassum sp. for Prevention of Organic Leaching and Enhancement of Uptake during Metal Biosorption. Ind Eng Chem Res 2005. [DOI: 10.1021/ie050678t] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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140
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Paul Chen J, Lim LL. Recovery of precious metals by an electrochemical deposition method. CHEMOSPHERE 2005; 60:1384-92. [PMID: 16054907 DOI: 10.1016/j.chemosphere.2005.02.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2003] [Revised: 02/01/2005] [Accepted: 02/01/2005] [Indexed: 05/03/2023]
Abstract
Conversion of soluble precious metals into a solid form for further reuse was studied by using an electrochemical deposition approach. It was found that the metal recovery followed a first-order reaction kinetics. The distance between the electrodes had no much impact on the recovery, while higher mixing led to faster kinetics. The presence of humic acid (HA) with lower concentration (<20mg l (-1)) did not have impact on the recovery. When its concentration was increased to 50 mg l (-1), it decreased the metal reduction. Presence of ethylene diamine tetraacetic acid (EDTA) and ionic strength slightly reduced the copper recovery rate. Around 50% removal of for HA and EDTA was achieved. In the competing environment, metal recovery was in the following order: silver>lead>copper. X-ray photoelectron spectroscopic and scanning electronic microscopic analysis of the reduced metals demonstrated that the depositions were composed of mainly elemental metals together with their oxides which were due to the oxidation.
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141
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Liu B, Xie J, Lee JY, Ting YP, Chen JP. Optimization of High-Yield Biological Synthesis of Single-Crystalline Gold Nanoplates. J Phys Chem B 2005; 109:15256-63. [PMID: 16852932 DOI: 10.1021/jp051449n] [Citation(s) in RCA: 181] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, single-crystalline gold nanoplates were obtained by reducing aqueous chloroauric acid solution with the extract of Sargassum sp. (brown seaweed) at room temperature. The gold nanoplates so obtained were characterized by UV-vis spectroscopy, X-ray diffraction, atomic force microscopy, and transmission electron microscopy. The formation of gold nanoplates was found to depend on a number of environmental factors, such as the time taken to age the seaweed extract, pH of the reaction medium, reaction temperature, reaction time, and initial reactant concentrations. The size of the gold nanoplates could be controlled to between 200 and 800 nm by manipulating the initial reactant concentrations. The yield of the flat gold nanocrystals relative to the total number of nanoparticles formed was as high as approximately 80-90%.
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142
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Zhou Y, Sun T, Chan M, Zhang J, Han Z, Wang X, Toh Y, Chen JP, Yu H. Scalable encapsulation of hepatocytes by electrostatic spraying. J Biotechnol 2005; 117:99-109. [PMID: 15831251 DOI: 10.1016/j.jbiotec.2004.11.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 10/27/2004] [Accepted: 11/18/2004] [Indexed: 11/27/2022]
Abstract
Encapsulating cells by polyelectrolyte complex coacervation can be accomplished at physiological temperature and buffer conditions. One of the oppositely charged polyelectrolytes in the microcapsule core can be collagen or any other natural extra-cellular matrices suitable for cellular support while the other polyelectrolyte forms the ultra-thin shell to ensure efficient mass transfer. These microcapsules with ultra-thin shell are difficult to produce in large quantities due to their fragility. In this study, electrostatic spraying technique was used to achieve a scalable production of one such type of microcapsules formed by complex coacervation between the cationic methylated collagen and anionic terpolymer of hydroxylethyl methacrylate, methyl methacrylate and methylacrylic acid (HEMA-MMA-MAA). It was found that the microcapsule sizes were dependent on several important operational parameters, such as the diameter of the spraying needle, the flow rate of the hepatocytes-collagen mixture and the voltage of the electrical field. The microcapsules with diameters of 200-800 microm and a narrow size distribution (standard deviation of 5-28%) were successfully produced. The above parameters also influenced the hepatocyte viability and functions. With a practical encapsulation rate of up to 55 ml/h per orifice required in bio-artificial liver-assisted device applications, we have produced large quantities of microcapsules maintaining comparable cell viability (>87%), mechanical stability and bio-functions to the manually extruded microcapsules.
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143
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Zhang CZ, Wang SX, Zhang Y, Chen JP, Liang XM. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. JOURNAL OF ETHNOPHARMACOLOGY 2005; 98:295-300. [PMID: 15814262 DOI: 10.1016/j.jep.2005.01.033] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Revised: 12/15/2004] [Accepted: 01/15/2005] [Indexed: 05/20/2023]
Abstract
The estrogenic activity of 70% EtOH extracts of 32 traditional Chinese medicinal plants, selected according to their reported efficacy for the treatment of menopausal symptoms, was assessed using a recombinant yeast system with both a human estrogen receptor expression plasmid and a reporter plasmid. Among them, 11 (34%) species proved to be active. Polygonum cuspidatum had the highest estrogenic relative potency (RP) (3.28 x 10(-3)), followed by Rheumpalmatum (3.85 x 10(-4)), Cassia obtusifolia (3.49 x 10(-4)), Polygonum multiflorum (2.87 x 10(-4)), Epimedium brevicornum (2.30 x 10(-4)), Psoralea corylifolia (1.90 x 10(-4)), Cynomorium songaricum (1.78 x 10(-4)), Belamcanda chinensis (1.26 x 10(-4)), Scutellaria baicalensis (8.77 x 10(-5)), Astragalus membranaceus (8.47 x 10(-5)) and Pueraria lobata (6.17 x 10(-5)). The EC(50) value of 17beta-estradiol used as the positive control was 0.205+/-0.025 ng/ml (RP=100). This study gave support to the reported efficacy of Chinese medicines used for hormone replacement therapy.
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Sheng PX, Tan LH, Chen JP, Ting Y. Biosorption Performance of Two Brown Marine Algae for Removal of Chromium and Cadmium. J DISPER SCI TECHNOL 2005. [DOI: 10.1081/dis-200027327] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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145
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Wu S, Li H, Chen JP. Modeling Investigation of Volume Variation Kinetics of Fast Response Hydrogels. ACTA ACUST UNITED AC 2004. [DOI: 10.1081/mc-120034151] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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146
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Chen JP, Wu S. Simultaneous adsorption of copper ions and humic acid onto an activated carbon. J Colloid Interface Sci 2004; 280:334-42. [PMID: 15533405 DOI: 10.1016/j.jcis.2004.08.029] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2004] [Accepted: 08/06/2004] [Indexed: 11/22/2022]
Abstract
In this study, simultaneous adsorption of copper ions and humic acid (HA) from Aldrich onto an activated carbon is investigated. It is found that the HA adsorption in the absence of copper decreases as the pH is increased. It leads to a reduction of 34.7% in the specific surface area of carbon. There exists a critical concentration (CC) of HA for copper adsorption. At HA concentrations < CC, a decrease in copper adsorption is observed; however, the HA improves the adsorption at HA concentrations > CC. An increase in ionic strength can enhance the copper uptake; however, zinc and/or cobalt ions have an insignificant influence on copper adsorption. The adsorption is significantly increased by citric acid, whereas addition of EDTA slightly decreases the uptake. An intraparticle diffusion model is successfully used to describe the copper adsorption kinetics.
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147
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Chen JP, Tai CY, Chen BH. Improved liquid chromatographic method for determination of carotenoids in Taiwanese mango (Mangifera indica L.). J Chromatogr A 2004; 1054:261-8. [PMID: 15553152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
An HPLC method was developed to determine the various carotenoids in Taiwanese mango (Mangifera indica L.). Initially, the peel and seed of mangoes were removed, the pulps were cut into pieces, freeze-dried, ground into powder, extracted and subjected to HPLC analysis. A mobile phase of methanol-isopropanol (99:1, v/v) (A) and methylene chloride (100%) (B) with the following gradient elution was developed: 100% A and 0% B in the beginning, maintained for 15 min, decreased to 70% A in 45 min, maintained for 15 min and returned to 100% A in 65 min. A total of 25 carotenoids were resolved within 53 min by using a C-30 column with flow rate at 1 mL/min and detection at 450 nm. alpha-Carotene was used as an internal standard to quantify all the carotenoids. All-trans-beta-carotene was present in largest amount (29.34 microg/g), followed by cis isomers of beta-carotene (9.86 microg/g), violaxanthin and its cis isomers (6.40 microg/g), neochrome (5.03 microg/g), luteoxanthin (3.6 microg/g), neoxanthin and its cis isomers (1.88 microg/g), zeaxanthin (1.16 microg/g) and 9- or 9'-cis-lutein (0.78 microg/g).
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Kozlov A, Sarty AJ, Aniol KA, Bartsch P, Baumann D, Bertozzi W, Bohinc K, Böhm R, Chen JP, Dale D, Dennis L, Derber S, Ding M, Distler MO, Dragovitsch P, Ewald I, Fissum KG, Friedrich J, Friedrich JM, Geiges R, Gilad S, Jennewein P, Kahrau M, Kohl M, Krygier KW, Liesenfeld A, Margaziotis DJ, Merkel H, Merle P, Müller U, Neuhausen R, Pospischil T, Potokar M, Riccardi G, Roché R, Rosner G, Rowntree D, Schmieden H, Sirca S, Templon JA, Thompson MN, Wagner A, Walcher T, Weis M, Zhao J, Zhou ZL, Golak J, Glöckle W, Witała H. Measurement of the exclusive 3He(e,e'p) reaction below the quasielastic peak. PHYSICAL REVIEW LETTERS 2004; 93:132301. [PMID: 15524710 DOI: 10.1103/physrevlett.93.132301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2002] [Revised: 12/16/2003] [Indexed: 05/24/2023]
Abstract
New, high-precision measurements of the 3He(e,e(')p) reaction using the A1 Collaboration spectrometers at the Mainz microtron MAMI are presented. These were performed in antiparallel kinematics at energy transfers below the quasielastic peak, and at a central momentum transfer of 685 MeV/c. Cross sections and distorted momentum distributions were extracted and compared to theoretical predictions and existing data. The longitudinal and transverse behavior of the cross section was also studied. Sizable differences in the cross-section behavior from theoretical predictions based on the plane wave impulse approximation were observed in both the two- and three-body breakup channels. Full Faddeev-type calculations account for some of the observed excess cross-section, but significant differences remain.
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Sheng PX, Ting YP, Chen JP, Hong L. Sorption of lead, copper, cadmium, zinc, and nickel by marine algal biomass: characterization of biosorptive capacity and investigation of mechanisms. J Colloid Interface Sci 2004; 275:131-41. [PMID: 15158390 DOI: 10.1016/j.jcis.2004.01.036] [Citation(s) in RCA: 470] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Accepted: 01/20/2004] [Indexed: 10/26/2022]
Abstract
The marine algae Sargassum sp., Padina sp., Ulva sp., and Gracillaria sp., harvested locally, were investigated for their biosorption performance in the removal of lead, copper, cadmium, zinc, and nickel from dilute aqueous solutions. It was found that the biosorption capacities were significantly affected by solution pH, with higher pH favoring higher metal-ion removal. Kinetic and isotherm experiments were carried out at the optimal pH: at pH 5.0 for lead and copper, and at pH 5.5 for cadmium, zinc, and nickel. The metal removal rates were rapid, with 90% of the total adsorption taking place within 60 min. Sargassum sp. and Padina sp. showed the highest potential for the sorption of the metal ions, with the maximum uptake capacities ranging from 0.61 to 1.16 mmol/g for Sargassum sp. and 0.63 to 1.25 mmol/g for Padina sp. The general affinity sequence for Padina sp. was Pb>Cu>Cd>Zn>Ni, while that for Sargassum sp. was Pb>Zn>Cd>Cu>Ni. XPS and FTIR analysis of Sargassum sp. and Padina sp. revealed the chelating character of the ion coordination to carboxyl groups. It was confirmed that carboxyl, ether, alcoholic, and amino groups are responsible for the binding of the metal ions.
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Chen JP, Wu S. Acid/Base-treated activated carbons: characterization of functional groups and metal adsorptive properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:2233-42. [PMID: 15835676 DOI: 10.1021/la0348463] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Surface modification of activated carbons by various physicochemical methods directs an attractive approach for improvement of heavy metal uptake from aqueous solutions. Activated carbons were modified with HCl and HNO3 optionally followed by NaOH. The effects of surface modifications on the properties of the carbons were studied by the specific surface area, carbon pH, and total acidity capacity as well as by scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The modifications bring about substantial variation in the chemical properties whereas the physical properties remain nearly unchanged. NaOH causes an increase in the content of hydroxyl groups, while the HCl treatment results in an increase in the amount of single-bonded oxygen functional groups such as phenols, ethers, and lactones. The HNO3 modification generates a large number of surface functional groups such as carbonyl, carboxyl, and nitrate groups. The HNO3 modification significantly increases the copper adsorption, while the HCl treatment slightly reduces the copper uptake. Most of the copper ions are adsorbed rapidly in the first 2 h; the adsorption equilibrium is established in around 8 h. An intraparticle diffusion model successfully describes the kinetics of copper adsorption onto the carbons.
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