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Adsorption and reduction from modified polypyrrole enhance electrokinetic remediation of hexavalent chromium-contaminated soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:44845-44861. [PMID: 35141822 DOI: 10.1007/s11356-022-18998-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Toxic metal pollutant Cr(VI) in the environment will pose a severe threat to animal and human health. In this work, Fe3O4@PPy, Arg@PPy, and Arg/Fe3O4@PPy were prepared to enhance adsorption of Cr(VI) by doping Fe3O4 nanoparticles and amino radicals into the original PPy structure. Their characteristics were investigated by FTIR, SEM, EDS, BET analysis, and batch adsorption experiments. And they were used as permeable reaction barriers (PRB) to combine with electrokinetic remediation (EKR) to remediate Cr-contaminated soil. Adsorption experiment results showed that the maximum adsorption capacities of PPy, Fe3O4@PPy, Arg@PPy, and Arg/Fe3O4@PPy for Cr(VI) were 60.43 mg/g, 67.12 mg/g, 159.86 mg/g, and 141.50 mg/g, respectively. They all followed the kinetic pseudo-second-order model and the Langmuir isothermal model with a monolayer adsorption behavior. In the EKR/PRB system, the presence of Fe3O4@PPy, Arg@PPy, and Arg/Fe3O4@PPy obtained the higher Cr(VI) removal efficiency near the anode than that of the PPy, increasing by 74.60%, 26.04%, and 68.64%, respectively. A strong electrostatic attraction between anion contaminants and protonated modified PPy and a reduction from Cr(VI) to Cr(III) appeared in the EKR remediation process under acid conditions. This study opened up a prospect for applying modified PPy composites to treat toxic metal-contaminated soil.
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Rapid Cr(VI) reduction structure in chromium contaminated soil: The UV-assisted electrokinetic circulation of background iron. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153508. [PMID: 35101496 DOI: 10.1016/j.scitotenv.2022.153508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/11/2022] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
Substantially decreasing the severe hazards connected with the toxic Cr(VI), developing effective reduction remediation strategies may be crucial under favorable economic conditions for the contaminated soil containing Cr(VI) to protect human health. Several typical enhancers (phosphate, fulvic acid, citric acid) were used to test electrokinetic remediation (EKR) coupled with UV radiation-induced photochemical reduction for contaminated soil containing Cr(VI). The added citrate, while improving the Cr(VI) electromigration, worked as the ultimate sacrificial electron donors, with the dissolved soil background Fe(III) as electron shuttle, to Cr(VI) rapid reduction. The dissolved soil background Fe(III) convert into Fe(II) ions through the UV radiation-induced ligand-metal charge transfers reaction, which constituted a novel electrokinetic circulation reduction pathway for the elimination of surface-bound/dissolved Cr(VI) (difficult to electromigration) in the near-anodic soil layers. More than 80% dissolved and surface-bound Cr(VI) was eliminated from the soil. In particular, the dissolved and surface-bound Cr(VI) was enhanced by more than 62.37% removal in near-anodic soil layers compared to conventional citric acid-enhanced EKR and provided no extra cost other than UV radiation. This configuration may be a cost-effective and feasible remediation design in the future for the in-situ Cr(VI) reduction of contaminated sites.
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Solidification of chromium-containing sludge with attapulgite combined alkali slag. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:13580-13591. [PMID: 34595712 DOI: 10.1007/s11356-021-16193-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
To solve the harm caused by hazardous chromium-containing sludge (CCS, chromium-containing sludge) waste to humans and the environment, this study used attapulgite to strengthen alkali slag to prepare cementitious materials to solidify/stabilize CCS. Single-factor and orthogonal experiments were used to optimize the preparation parameters of alkali slag cementitious materials. The compressive strength, heavy metal leaching toxicity, and microscopic characterization of a CCS solidified body were tested to investigate the solidification effect and mechanism of CCS formation. The best attapulgite content was 4%; the solidified body after the treatment of chromium-containing sludge had a good performance of heavy metal leaching and mechanical properties. The addition of attapulgite enhanced the compressive strength. Compared with the original CCS, the leaching concentration of heavy metals in the solidified body was significantly reduced. Among them, the solidified efficiency of chromium is stable above 90%. The changes in the results of XRD and FTIR for each component were studied. It indicated that the solidified body may solidify/stabilize heavy metals through physical encapsulation of the amorphous form and chemical immobilization. This research recognized the use of waste to treat waste, realized the combined effect of solidification/adsorption, and indicated the possibility of application of attapulgite and its solidified products in construction.
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The Utilization of Alkali-Activated Lead-Zinc Smelting Slag for Chromite Ore Processing Residue Solidification/Stabilization. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18199960. [PMID: 34639258 PMCID: PMC8508533 DOI: 10.3390/ijerph18199960] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 12/03/2022]
Abstract
Lead–zinc smelting slag (LZSS) is regarded as a hazardous waste containing heavy metals that poses a significant threat to the environment. LZSS is rich in aluminosilicate, which has the potential to prepare alkali-activated materials and solidify hazardous waste, realizing hazardous waste cotreatment. In this study, the experiment included two parts; i.e., the preparation of alkali-activated LZSS (pure smelting slag) and chromite ore processing residue (COPR) solidification/stabilization. Single-factor and orthogonal experiments were carried out that aimed to explore the effects of various parameters (alkali solid content, water glass modulus, liquid–solid ratio, and initial curing temperature) for alkali-activated LZSS. Additionally, compressive strength and leaching toxicity were the indexes used to evaluate the performance of the solidified bodies containing COPR. As a result, the highest compressive strength of alkali-activated LZSS reached 84.49 MPa, and when 40% COPR was added, the strength decreased to 1.42 MPa. However, the leaching concentrations of Zn and Cr from all the solidified bodies were far below the critical limits (US EPA Method 1311 and China GB5085.3-2007). Heavy-metal ions in LZSS and COPR were immobilized successfully by chemical and physical means, which was detected by analyses including environmental scanning electron microscopy with energy-dispersive spectrometry, Fourier transform infrared spectrometry, and X-ray diffraction.
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Preparation of Glass-Ceramics via Cosintering and Solidification of Hazardous Waste Incineration Residue and Chromium-Containing Sludge. ACS OMEGA 2021; 6:23723-23730. [PMID: 34568652 PMCID: PMC8459372 DOI: 10.1021/acsomega.1c01659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Indexed: 05/10/2023]
Abstract
Residues from the incineration of hazardous wastes are classified as hazardous byproducts because they contain heavy metals. Chromium-containing sludge (CCS) is industrial sludge produced during the electroplating process and includes heavy metals, such as Cr, Pb, and Cu. These heavy metals can infiltrate natural ecosystems and cause significant environmental damage. To limit the toxicity of leached products, hazardous waste incineration residues (HWIRs) can be repurposed as raw materials for producing glass-ceramics. In this study, we designed an orthogonal experiment to optimize the heat treatment process, yielding glass-ceramics with excellent properties and realizing heavy metal solidification. The toxic characteristic leaching procedure was used to determine the leaching toxicity of the cosintered solidified heavy metals, revealing that their solidification efficiencies exceed 90%. Moreover, X-ray diffraction analysis indicates that certain heavy metals participate in the formation of heavy-metal-containing crystal lattices (FeCr2O4 and PbFe12O19), thereby reducing their leaching concentration. These results show that cosintering HWIR and CCS is an effective approach for heavy metal solidification and provides valuable insights into its utilization for producing building materials.
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Application of UV radiation for in-situ Cr(VI) reduction from contaminated soil with electrokinetic remediation. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:125806. [PMID: 33873035 DOI: 10.1016/j.jhazmat.2021.125806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/03/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Restoring hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)) from contaminated soil is a cost-effective alternative for attenuating Cr(VI) toxicity to the ecosystem. A new electrokinetic remediation (EKR) system with UV light was explored to overcome an energy barrier to catalyze Cr(VI) reduction from the surface soil near the anodic reservoir. Natural organic matters and minerals from the contaminated soil acted as electron donors and catalysts for Cr(VI) photo-reduction and no additional chemical reagent. There was almost no residual Cr(VI) in anolyte after UV/EKR compared with the conventional EKR. The reduction improved the efficiency of EKR in the soil near the anodic reservoir by dropped the Cr(VI) negative mass flux caused by electroosmosis advection and concentration diffusion. The pathways of Cr(VI) photo-reduction are possibly dominated by ligand-to-metal charge transfer, i.e., photocatalytic cyclic reduction by Fe(III)/Fe(II) complexes on the surface of the minerals and in soil pore fluid and the photo-induced decomposition of chromate ester. It is concluded that UV/EKR is a clean, efficient, and low-cost method for remediation of Cr(VI)-contaminated soil.
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Efficient electrokinetic remediation of heavy metals from MSWI fly ash using approaching anode integrated with permeable reactive barrier. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:22156-22169. [PMID: 33417130 DOI: 10.1007/s11356-021-12340-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/02/2021] [Indexed: 06/12/2023]
Abstract
During electrokinetic remediation (EKR) of heavy metals (HMs) (Pb, Zn, Cu, and Cd) from municipal solid waste incineration (MSWI) fly ash enhanced by a permeable reactive barrier (PRB), the nearer to the anode, the higher the concentration of H+ ions and the greater the remediation effect. Therefore, a potentially new method of PRB-enhanced EKR using an approaching anode (A-EKR + PRB) was studied to help H+ ions to quickly migrate to the sample near the cathode. Consequently, the HM leaching and total concentrations were reduced, while an energy reduction of nearly 40% was achieved. The results showed that the best remediation ability was obtained when MSWI fly ash was treated for 16 days at a voltage gradient of 2.5 V/cm, the approaching anode was moved after 4 days, and the PRB contained 10 g of activated carbon. After remediation, the environmental risk analysis showed that A-EKR + PRB reduced all the fractions of HMs, especially the acid extractable and oxidizable fractions, which might have been due to the enhancement of acid dissolution and oxidation by the approaching anode. In addition, the environmental risks of the remaining HMs were reduced, and the results indicated that A-EKR + PRB is an advisable choice for remediation of MSWI fly ash.
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Detoxification and immobilization of chromite ore processing residue using the alkali-activated cementitious materials mixed with ascorbic acid. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 265:110350. [PMID: 32421549 DOI: 10.1016/j.jenvman.2020.110350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 05/25/2023]
Abstract
The existence of leachable Cr(Ⅵ) in chromite ore processing residue (COPR) makes it hazardous waste. Therefore, resourceful utilization of COPR is necessary to protect the ecosystem and living biota from hazardous effect of Cr(Ⅵ) caused by its leaching. In this study, detoxification and immobilization of COPR was carried out through introduction of ascorbic acid (AA) in alkali-activated cementitious materials. Several dosages of AA were treated with water extractable/soluble Cr(Ⅵ) to achieve the optimum dosage which could be further utilized in solidification process. While, the compressive strength was developed through utilizing different modulus of water glass, liquid to solid ratios and curing temperatures. The results showed that 0.3% of AA was enough to reduce the Cr(Ⅵ) into Cr(Ⅲ), and highest compressive strength of 120 MPa was achieved after using the modulus of 1.6, liquid to solid ratio of 0.24 and curing temperature of 30 °C. The solidified samples having AA had not exceeded the toxicity limit up to 60% addition of COPR, and samples without addition of AA were effective for solidification of 20% COPR. Regarding mechanism, the compressive strength, leaching behavior and microscopic analysis i.e. X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR) and scanning electron microscope with energy dispersive spectrometry (SEM-EDS) showed that immobilization of chromium was carried out through physical and chemical means.
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Synergism of citric acid and zero-valent iron on Cr(VI) removal from real contaminated soil by electrokinetic remediation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:5572-5583. [PMID: 31853846 DOI: 10.1007/s11356-019-06820-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
This study focused on enhanced electrokinetic remediation of Cr(VI) in real contaminated soil. The citric acid (CA) as the electrolyte and Fe(II) released from zero-valent iron (ZVI) under anoxic conditions functioned as the main reducer. They were used for overcoming the high insoluble Cr(VI) fraction in real contaminated soil and high Cr(VI) residue in acidic soil near the anode simultaneously. The synergism of CA and ZVI is that CA helps the release of Cr(VI) to react with the generated Fe(II) and alleviates the hindrance of Fe and Cr co-precipitates in electromigration of Cr; meanwhile, the end product Fe(III) from ZVI catalyzed the Cr(VI) reduction by CA. The removal of Cr(III) and Cr(VI) was significantly improved in real contaminated soil. The optimum result (82.86%) was obtained at a voltage gradient of 2.5 V/cm after 12-day remediation with a 10 g ZVI dose when the catholyte and anolyte were 0.2 mol/L and 0.1 mol/L CA, respectively. This configuration has a significant improvement in overcoming the current obstacles for Cr(VI) electrokinetic remediation from real contaminated soil and prospects for large-scale practical applications.
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Solidification of electroplating sludge with alkali-activated fly ash to prepare a non-burnt brick and its risk assessment. RSC Adv 2020; 10:4640-4649. [PMID: 35495242 PMCID: PMC9049070 DOI: 10.1039/c9ra08475d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 01/11/2020] [Indexed: 11/30/2022] Open
Abstract
Electroplating sludge (ES), a byproduct of the electroplating industry, is considered as hazardous waste because of the presence of several kinds of toxic heavy metals (HMs, i.e., Cr, Ni, Cu and Zn). The improper treatment of ES has resulted in the contamination of the environment and is ultimately harmful to the living biota. Solidification/stabilization is regarded as a promising technique to deal with hazardous wastes with the use of a geopolymer, an excellent material, in this technique. In this research, ES was solidified using fly ash (FA) and ordinary Portland cement together so that non-burnt bricks (NBBs) could be prepared. The risk assessment of these bricks was carried out in a homemade experimental device by simulating rainfall. The results showed that the compressive strength of NBBs was up to 15 MPa; hence, it could be used for construction purposes. The hazard quotient (HQ) of HMs (including Zn, Ni and Cu) was much less than the limit value, while both the HQ and cancer risk of Cr were over the corresponding limit values. Electroplating sludge was solidified in alkali activated fly ash to prepare non-burnt bricks, and their risk to humans was assessed.![]()
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Solidification/stabilization of municipal solid waste incineration fly ash using uncalcined coal gangue-based alkali-activated cementitious materials. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:25609-25620. [PMID: 31267393 DOI: 10.1007/s11356-019-05832-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/24/2019] [Indexed: 06/09/2023]
Abstract
The proper disposal of municipal solid waste incineration fly ash (MSWI FA) is necessary due to the presence of hazardous metals (Cu2+, Zn2+, Pb2+ and Cd2+). The solidification/stabilization through alkali-activated cementitious materials (having aluminosilicates) is regarded as one of the best methods for its disposal. In this paper, an uncalcined coal gangue-based alkali-activated cementitious material was used to solidify the MSWI FA. The compressive strength of these cementitious materials was evaluated through different contents of alkali activators, SiO2/Na2O molar ratios, liquid/solid ratios and curing temperatures by utilizing a single-factor experiment. The specimens with the highest compressive strength (31.37 MPa) were used for solidification of MSWI FA. The results indicated that compressive strength decreased with the addition of MSWI FA which caused the higher leaching of heavy metals. The solidification efficiencies of Cu2+, Zn2+, Pb2+ and Cd2+ were more than 95%. In addition, leaching concentrations had not surpassed the critical limit up to 20% addition of MSWI FA in solidified samples and representing the potential application of these samples for construction and landfill purposes. Heavy metals in MSWI FA were solidified through physical encapsulation and chemical bonding which was verified by speciation analysis, X-ray diffraction, Fourier transform infrared spectrometry and scanning electron microscopy with energy dispersive spectrometry analyses.
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Efficient removal of chromium from soil in a modified electrokinetic system using iron-treated activated carbon as third electrode. J Taiwan Inst Chem Eng 2019. [DOI: 10.1016/j.jtice.2019.03.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Effect of chemical additives on electrokinetic remediation of Cr-contaminated soil coupled with a permeable reactive barrier. ROYAL SOCIETY OPEN SCIENCE 2019; 6:182138. [PMID: 31218039 PMCID: PMC6549979 DOI: 10.1098/rsos.182138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/26/2019] [Indexed: 05/11/2023]
Abstract
Chromium (Cr) contamination in soil, especially Cr(VI), is a serious threat to the environment and human health. The electrokinetic remediation (EKR) is a promising technology to remediate the Cr(VI). Therefore, in this study, EKR coupled with a permeable reactive barrier (PRB) was used to treat the Cr(VI)-contaminated soil. The CTMAB-Z, a modified zeolite (prepared with cetyltrimethyl ammonium bromide) alone and a mixture of CTMAB-Z and Fe(0) were used as PRB-1 and PRB-2 reactive media, respectively. The effect of chemical enhancers/additives, i.e. DL-tartaric acid and Tween 80 on EKR of Cr(VI) was also analysed in the contrasting experiments. While the effects of repair time, voltage gradient and DL-tartaric acid concentration on Cr(VI) remediation were investigated by using the multifactor orthogonal experiment which was based on contrasting experiments. The contrasting experiment results showed that the highest Cr(VI) removal rate (66.27%) and leaching efficiency (71.29%) were observed in the experimental group which had DL-tartaric acid and PRB-2. Furthermore, the multifactor orthogonal experiment results had depicted that the highest Cr(VI) removal rate (80.92%) and leaching efficiency (85.25%) were achieved after treating the samples at a voltage gradient of 2.5 V cm-1 for 8 days in the presence of 0.15 M concentration of DL-tartaric acid. This study demonstrated that Cr(VI) remediation through EKR process could be significantly enhanced by the use of PRB and additives.
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Electrokinetic remediation of heavy metals from municipal solid waste incineration fly ash pretreated by nitric acid. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180372. [PMID: 30225023 PMCID: PMC6124067 DOI: 10.1098/rsos.180372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/04/2018] [Indexed: 05/19/2023]
Abstract
Municipal solid waste incineration (MSWI) fly ash has a high concentration of heavy metals (HMs) which are hazardous to the environment. Moreover, it has high pH and buffering capacity which hinders the removal of HMs. Another constraining factor is the considerable fraction of HMs which exist in oxidizable and reducible states. The acid pretreatment of MSWI fly ash is a key solution to this problem. Therefore, the current experiment is carried out to evaluate the effect of acid pretreatment of MSWI fly ash and reaction/proposed time on the removal efficiency of HMs through an electrokinetic experiment. The leaching experiment results show that acid pretreatment has increased the desorption/release of heavy metal ions (Pb2+, Cd2+, Cu2+ and Zn2+). It enhances the migration of HM ions in electrolytic cells which get precipitated at the cathode, thereby increasing the removal efficiency of HMs in the electrokinetic experiment. Moreover, it is found that prolonged proposed time (12 d) has significant effect on the removal efficiency of HMs. Finally, it is concluded that acid pretreatment and prolonged proposed time have enhanced the removal electrokinetic remediation of HMs which is carried out via three processes, i.e. desorption (enhanced by acidification), migration and precipitation.
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Application of iron-loaded activated carbon electrodes for electrokinetic remediation of chromium-contaminated soil in a three-dimensional electrode system. Sci Rep 2018; 8:5753. [PMID: 29636517 PMCID: PMC5893631 DOI: 10.1038/s41598-018-24138-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 03/19/2018] [Indexed: 11/09/2022] Open
Abstract
Hexavalent chromium from industrial residues is highly mobile in soil and can lead to the contamination of groundwater through runoff and leaching after rainfall. This paper focuses on the three-dimensional (3D) electrokinetic remediation (EKR) of chromium-contaminated soil from an industrial site. Activated carbon particles coupled with Fe ions (AC-Fe) were used as the third electrode. The optimum dose ratio of the electrode particles and remediation time were selected on the basis of single-factor experiments. X-ray photoelectron spectroscopy (XPS) analysis was carried out to explore the reduction of Cr(VI) on the surface of the electrode particles (AC-Fe). The results showed that AC-Fe had a positive effect on Cr(VI) reduction with a removal rate of 80.2%, which was achieved after 10 d by using a 5% dose of electrode particles. Finally, it was concluded that the removal mechanism combined the processes of electromigration, electrosorption/adsorption and reduction of Cr(VI) in the 3D EKR system.
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Waste solidification/stabilization of lead–zinc slag by utilizing fly ash based geopolymers. RSC Adv 2018; 8:32956-32965. [PMID: 35547705 PMCID: PMC9086302 DOI: 10.1039/c8ra06634e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 09/06/2018] [Indexed: 12/03/2022] Open
Abstract
Solidification/stabilization (S/S) is recognized as an effective technology for solid waste treatment. In S/S, the application of geopolymers synthesized by industrial waste (rich in active silicon and aluminum) to immobilize hazardous waste is a research focus. In this article, a fly ash based geopolymer was used to immobilize lead–zinc slag containing Pb, Ni, Zn and Mn. A fly ash based geopolymer with good mechanical strength was obtained through single factor experiments and the compressive strength of the geopolymer reached 29.72 MPa. The effects of immobilizing lead–zinc slag in the fly ash based geopolymer were discussed by means of compressive strength, leaching test and speciation analysis. The solidification/stabilization mechanism was further investigated using XRD, FTIR and SEM. The mechanical properties of the fly ash based geopolymer were negatively affected by addition of lead–zinc slag, and compressive strength decreased to 8.67 MPa when 60% lead–zinc slag was added. The geopolymer has the ability to reduce toxicity of lead–zinc slag by immobilizing heavy metals (Pb, Ni, Zn and Mn), but the ability was not unlimited. The migration of heavy metals to residual form indicates that heavy metals may either be bonded into the geopolymer matrix via the T–O bond (T = Si, Al) or captured in framework cavities to maintain the charge balance. The NASH (Na2O–Al2O3–SiO2–H2O) gel structure observed by XRD, FTIR and SEM can physically encapsulate the contaminants during geopolymerization. It is finally concluded that heavy metals were immobilized in the fly ash based geopolymer through a combination of chemical bonding and physical encapsulation. The toxicity of lead–zinc slag was significantly reduced by chemical and physical ways during immobilization.![]()
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CDKN2B deletion is essential for pancreatic cancer development instead of unmeaningful co-deletion due to juxtaposition to CDKN2A. Oncogene 2017; 37:128-138. [PMID: 28892048 PMCID: PMC5759028 DOI: 10.1038/onc.2017.316] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 06/07/2017] [Accepted: 07/31/2017] [Indexed: 12/28/2022]
Abstract
Pancreatic cancer is among the deadliest malignancies; however, the genetic events that lead to pancreatic carcinogenesis in adults remain unclear. In vivo models in which these genetic alterations occur in adult animals may more accurately reflect the features of human cancer. In this study, we demonstrate that inactivation of Cdkn2b (p15ink4b) is necessary for induction of pancreatic cancer by oncogenic KRASG12D expression and inactivation of Tp53 and Cdkn2a in adult mouse pancreatic ductal cells (P60 or older). KRASG12D overexpression in these cells activated transforming growth factor-β signaling and expression of CDKN2B, which, along with CDKN2A, led to cellular senescence and protected cells from KRAS-mediated transformation via inhibition of retinoblastoma phosphorylation. These results show a critical role of CDKN2B inactivation in pancreatic carcinogenesis, and provide a useful adult animal model by genetic engineering via lentiviral delivery.
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Electro-kinetic remediation of chromium-contaminated soil by a three-dimensional electrode coupled with a permeable reactive barrier. RSC Adv 2017. [DOI: 10.1039/c7ra10913j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electro-kinetic remediation of Cr-contaminated soil by three-dimensional electrode coupled with a permeable reactive barrier.
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Study on electro-kinetic remediation of heavy metals in municipal solid waste incineration fly ash with a three-dimensional electrode. RSC Adv 2017. [DOI: 10.1039/c7ra01327b] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Heavy metals of fly ash from incinerated municipal solid waste were removed by electro-kinetic remediation with three-dimensional electrode.
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The application of homemade Neosinocalamus affinis AC in electrokinetic removal technology on heavy metal removal from the MSWI fly ash. Sci Rep 2016; 6:39312. [PMID: 28000710 PMCID: PMC5175160 DOI: 10.1038/srep39312] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 11/22/2016] [Indexed: 11/09/2022] Open
Abstract
This present paper was focused on the manufacture of activated carbon (AC) and its application in the electrokinetic remediation (EKR) technology on removal of the heavy metals (HMs) from the municipal solid waste incineration fly ash. AC was produced from Neosinocalamus affinis (NF) by chemical activation with H3PO4 in N2 atmosphere, the effects of activation temperatures, soaking time and impregnation ratios on the adsorption capacity of AC on HMs were examined through equilibrium adsorption experiments. The AC produced under the condition of 450 °C of activation temperature, 10 h of soaking time and 1.5 of impregnation ration was applied in the EKR experiment. The addition of AC in the S3-region of the electrolyzer could effectively improve the removal efficiencies of HMs. The technical parameters of voltage gradient, processing time and proportion were further optimized in the coupled experiments, the maximum removal of Cu, Zn, Cd, and Pb was 84.93%, 69.61%, 79.57%, and 78.55% respectively obtained under the optimal operating conditions of 2 V/cm of voltage gradient, 8 d of processing time and 20% of proportion.
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Vincristine promotes migration and invasion of colorectal cancer HCT116 cells through RhoA/ROCK/ Myosin light chain pathway. CELLULAR AND MOLECULAR BIOLOGY (NOISY-LE-GRAND, FRANCE) 2016; 62:91-96. [PMID: 27894406 DOI: 10.14715/cmb/2016.62.12.16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 11/26/2016] [Indexed: 11/18/2022]
Abstract
Vincristine is an antitumor vinca alkaloid isolated from vinca rosea, and is a medication used to treat a number of types of cancer. In this study, we investigated the impact of vincristine on oncogenic phenotypes of human colorectal cancer HCT116 cells. MTT assay demonstrated that vincristine showed a obviously inhibitory effect on cell growth compared to non-treated cells. However, Transwell assay showed that vincristine promoted migration and invasion of HCT116 cells in vitro in a concentration-dependent manner between 0.5 and 15 μM vincristine treatment, whereas cell growth showed no remarkable difference within the same concentration range. Additionally, Western blot analysis showed that vincristine significantly elevated RhoA activity and Myosin light chain (MLC) phosphorylation, suggesting the involvement of RhoA/ROCK pathway in the vincristine-induced enhancement of cellular motility. Furthermore, we found that both the siRNA for RhoA and ROCK inhibitor Y27632 attenuated the phosphorylation of MLC, as well as vincristine-induced migration and invasion. These data indicate that vincristine enhanced migration and invasion of HCT116 cells possibly through stimulating RhoA/ROCK/MLC signaling pathway.
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Palmitoylacyltransferase Zdhhc9 inactivation mitigates leukemogenic potential of oncogenic Nras. Leukemia 2015; 30:1225-8. [PMID: 26493479 DOI: 10.1038/leu.2015.293] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Comparative study of photodynamic therapy with 5%, 10% and 20% aminolevulinic acid in the treatment of generalized recalcitrant facial verruca plana: a randomized clinical trial. J Eur Acad Dermatol Venereol 2013; 28:1821-6. [PMID: 24267796 DOI: 10.1111/jdv.12319] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 10/11/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Generalised recalcitrant facial verruca plana responds poorly to current therapeutic options, including cryotherapy, topical drugs and carbon dioxide (CO2 ) laser. Case reports and uncontrolled studies suggested that topical photodynamic therapy (PDT) is effective choice of treatment free from potential complications associated with invasive therapies. AIMS To investigate the efficacy and safety of PDT with different concentrations of photosensitiser in the treatment of verruca plana. MATERIALS & METHODS The two sides of a subject's face were separately randomized to receive aminolevulinic acid (ALA) of 5%, 10% or 20% concentration. All patients were irradiated with 633-nm red light for 339 J/cm(2) total dose. Complete response (CR) rate was assessed on Week 4, 8, and 16 respectively. RESULTS The mean overall clearance rate was 74.1%, 68.8%, and 64.6% on Week 4, 8, and 12, respectively, in the 110 treated sides. The CR rate was lower in the 5%-ALA group than in the 10%-ALA group (14.3% vs. 33.3%, p < 0.05) and 20%-ALA group (14.3% vs. 26.3%, p < 0.05) after 12 weeks. The mean severity of pain measured by visual analogue scale (VAS) scoring was 3.8 (range: 2 to 10, depending on the lesion location). The overall recurrence rate was 16.7% (4/24) on Week 12. Hyperpigmentation was observed in 61% (67/110) of all treated sides. On Week 4, 8, and 16, hyperpigmentation was more developed in the 20%-ALA group than in the other two groups (p < 0.05). DISCUSSION In terms of complete clearance rate, the 5% ALA-PDT group was significantly inferior to the 10% and 20% ALA-PDT groups at each follow-up. In contrast, the 20% ALA group showed a higher incidence rate of transient hyperpigmentation than the other two groups. CONCLUSIONS This randomised clinical trial suggests that PDT with ALA of 10% concentration offers better efficacy and safety than 5% or 20% concentration for generalised recalcitrant facial verruca plana.
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Upregulation of microRNA-224 confers a poor prognosis in glioma patients. Clin Transl Oncol 2012; 15:569-74. [PMID: 23263909 DOI: 10.1007/s12094-012-0972-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 11/14/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE MicroRNA-224 (miR-224) has been consistently reported to be dysregulated in various human malignancies and can potentially affect many cancer-related cellular processes, including transcription, cell differentiation, cell death, growth, and cell proliferation. However, its roles in human glioma have not been reported. The aim of this study was to explore the expression pattern, clinical significance, and prognostic value of miR-224 in glioma patients using large cohorts. METHODS Quantitative real-time polymerase chain reaction analysis was used to characterize the expression patterns of miR-224 in 108 glioma and 20 normal brain tissues. The associations of miR-224 expression with clinicopathological factors and prognosis of glioma patients were also statistically analyzed. RESULTS miR-224 expression is significantly upregulated in glioma tissues compared with normal brain tissues (P < 0.001). In addition, high expression of miR-224 was significantly associated with advanced pathological grade (P = 0.006) and low Karnofsky performance score (KPS, P = 0.01). Moreover, Kaplan-Meier survival analysis showed that high miR-224 expression group had significantly shorter disease-free survival (DFS) and overall survival (OS) rates than low miR-224 expression group (both P < 0.001). Multivariate analysis with the Cox's proportional hazards model revealed that high expression of miR-224 (P = 0.006 and P = 0.01, respectively) and advanced pathological grade (both P = 0.02) were independent factors for shorter DFS and OS. Furthermore, subgroup analyses showed that miR-224 expression was significantly associated with poor DFS and OS in glioma patients with high pathological grades (for grade III-IV: P < 0.001 and P = 0.005, respectively). CONCLUSIONS MiR-224 is upregulated and confers a poor prognosis in glioma patients.
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A low-dose combination of valsartan and low molecular weight heparin better improved glomerular permeability than did high-dose monotherapy in rats with diabetic nephropathy. Drug Discov Ther 2012; 5:119-24. [PMID: 22466240 DOI: 10.5582/ddt.2011.v5.3.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Diabetic nephropathy is the most common and severe renal complication of diabetes mellitus. The present study sought to investigate the renoprotective effects of a combination therapy of valsartan and low molecular weight heparin (LMWH) in rats with diabetic nephropathy induced by uninephrectomy and streptozotocin. The animals were divided into five groups as follows: sham-operated rats, diabetic control rats, diabetic rats treated with 20 mg/kg/day valsartan, diabetic rats treated with 600 IU/kg/day LMWH, diabetic rats treated with a combination of valsartan and LMWH (valsartan 10 mg/kg/day and LMWH 300 IU/kg/day). The treatment regimen was maintained for 8 weeks. Treatment with valsartan, LMWH, or a combination of the two had no significant effect on blood glucose levels. However, the urine protein excretion levels significantly decreased for the three drug treatment groups; the most dramatic decreases were observed in the combination treatment group. Kidney histology was examined using periodic acid-Schiff staining and immunohistochemical staining of extracellular matrix proteins. Results indicated that histopathology improved markedly in the three drug treatment groups; combination therapy had an equal or better effect than monotherapy in terms of decreasing the abnormal thickness of the glomerular basal membrane, the ratio of the area of the mesangial region with respect to the total area of renal glomeruli, and the accumulation of collagen IV and laminin in kidney tissue. In addition, serum levels of transforming growth factor-β1 (TGF-β1) also markedly decreased in the drug treatment groups according to ELISA. However, there were no significant differences between the combination therapy group and monotherapy group. These results suggest that a combination of valsartan and LMWH at half the dose used in monotherapy is better at improving glomerular permeability in rats with diabetic nephropathy.
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Valsartan attenuated oxidative stress, decreased MCP-1 and TGF-β1 expression in glomerular mesangial and epithelial cells induced by high-glucose levels. Biosci Trends 2012; 5:173-81. [PMID: 21914953 DOI: 10.5582/bst.2011.v5.4.173] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Our previous studies revealed that valsartan, an angiotensin II type I receptor blocker, exhibited renoprotective effects through decreasing urine protein excretion levels due to improving glomerular permeability in rats with diabetic nephropathy (DN). In this study, we sought to investigate the underlying mechanisms in perspectives of oxidative stress, transforming growth factor beta-1 (TGF-β1) and monocyte chemoattractant protein-1 (MCP-1) expressions in glomerular mesangial cells (GMCs) and glomerular epithelial cells (GECs) since their roles are well-established in the development and progression of DN. High-glucose levels significantly increased oxidative stress in GMCs and GECs, as evidenced by enhanced generation of reactive reactive oxygen species (ROS), reduced levels of glutathione (GSH) and antioxidant enzyme superoxide dismutase (SOD), and increased production of malondialdehyde (MDA). Treatment with valsartan significantly restored the levels of those oxidative stress relevant molecules. Furthermore, valsartan obviously diminished the expression of proinflammatory cytokine MCP-1 in GMCs and GECs induced by high-glucose levels both at mRNA and protein levels, as determined by real-time PCR, immunocytochemistry, western blotting, and ELISA. In addition, the increased expressions of TGF-β1 mRNA and protein induced by high-glucose level were also abrogated by valsartan treatment in GMCs, as evaluated by real-time PCR and ELISA. These results suggest that the renoprotective effects of valsartan may be related to its potential in decreasing oxidative stress and the expressions of MCP-1 and TGF-β1 in GMCs and GECs.
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Marine Microbes-Derived Anti-Bacterial Agents. Mini Rev Med Chem 2010; 10:1077-90. [DOI: 10.2174/1389557511009011077] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 07/25/2010] [Indexed: 11/22/2022]
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Characterization and Protection on Acute Liver Injury of a Polysaccharide MP-I from Mytilus Coruscus. Glycobiology 2007; 18:97-103. [DOI: 10.1093/glycob/cwm116] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Optical readout uncooled infrared imaging detector using knife-edge filter operation. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/s11801-007-7014-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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[Effect and mechanism of garlic juice and hydrogen peroxide on the degradation of lipopolysaccharide]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 2000; 35:333-5. [PMID: 11780236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To elucidate the effect and mechanism of garlic juice and hydrogen peroxide on the degradation of lipopolysaccharide (LPS). METHODS Hot phenol-water method, phenol-chloroform-petroleum ether procedure, limulus lysate test, lowry's ash spetrographical examination and gas-liquid chromatography etc. were used in this study. RESULTS The sequence of degradation effect was 30% hydrogen peroxide (H), the most powerful, followed by garlic juice (G), 1:1 diluted G and 3% H, their effects were dose dependent and G group was time dependent. The mechanism of H on LPS degradation was fractionization of phosphoryl in position 1 from lipid A, while that of G was complex, it could bound LPS molecule and influenced its effect besides LPS hydrolysis. CONCLUSION The study may imply that the degradation position and mechanism on LPS are different and remain to be elucidated.
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[The application of Apo-1/Fas to evaluate apoptosis of myocardial cells in patients with congestive heart failure]. ZHONGHUA NEI KE ZA ZHI 1999; 38:168-70. [PMID: 11798644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To study the changes of serum level of Apo-1/Fas in patients with congestive heart failure (CHF) and evaluate apoptosis of failing myocardial cells. METHODS Strepavidin-Biotin ELISA was used to determine serum level of Apo-1/Fas, interleukin-6 (IL-6) and tumor necrosis factor (TNF alpha) in 60 patients with CHF. Cardiac ejection fraction (EF) of the patients were measured by acusson 128XP/10 echocardiograph. RESULTS Serum levels of Apo-1/Fas and TNF alpha in class III and IV patients with CHF were significantly higher than those in class I and II (P < 0.01). Serum levels of IL-6 in all the patients were obviously higher than those in controls (P < 0.05 and 0.01) and the levels in class III and IV patients were significantly higher than those in class I and II (P < 0.05). Serum levels of Apo-1/Fas in patients with EF < 55 percent were higher than in those with EF > 55 percent (P < 0.05). CONCLUSION Serum level of Apo-1/Fas in patients with CHF reflects a state of apoptosis in failing myocardial cells. IL-6 and TNF alpha have important effects on immune regulation of myocardial cell apoptosis.
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Ultraphatological observation on the small brain abscess caused by cysticerci of taenia a solium: a double · necrosis (apoptosis) theory about the formation and development of the abscesses. Parasitol Int 1998. [DOI: 10.1016/s1383-5769(98)81043-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Comparative observation on effect of electric acupuncture of neiguan (P 6) at chen time versus xu time on left ventricular function in patients with coronary heart disease. J TRADIT CHIN MED 1994; 14:262-5. [PMID: 7877334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Paired experimental design was adopted in this experiment for comparative observation on effect of electric acupuncture (EA) of Neiguan (P 6) at Chen Time (7 a.m. to 9 a.m.) versus Xu Time (7 p.m. to 9 p.m.) on left ventricular function in patients with coronary heart disease (CHD). The results show that EA performed at Chen Time could improve the left ventricular function of CHD patients as indicated by shortening of PEPI and decrease of PEPI/LVETI ratio; on the contrary, EA performed at Xu Time prolonged PEPI and raised PEPI/LVETI ratio in CHD patients, suggesting impairment of left ventricular function.
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