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Alhamzani AG, Yousef TA, Abou-Krisha MM, Kumar KY, Prashanth MK, Parashuram L, Hun Jeon B, Raghu MS. Fabrication of layered In 2S 3/WS 2 heterostructure for enhanced and efficient photocatalytic CO 2 reduction and various paraben degradation in water. Chemosphere 2023; 322:138235. [PMID: 36841457 DOI: 10.1016/j.chemosphere.2023.138235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/31/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Because of the excessive use of fossil fuels, CO2 emissions into the environment are increasing. An efficient method of converting CO2 to useful carbonaceous products in the presence of light is one way to address the issues associated with energy and environmental remediation. In2S3/WS2 heterostructure has been fabricated using the efficient hydrothermal method. The results of structural, morphological, optical, and photo/electrochemical characterization confirm the formation of a hierarchical, layered heterostructure of type-II. Enhanced photocatalytic activity is observed in InS/WS heterostructure compared to pristine In2S3 and WS2. InS/WS heterostructure exhibit higher photocatalytic activity than pure In2S3 and WS2. For 12 h, photocatalytic CO2 reduction produces 213.4 and 188.6 μmol of CO and CH4, respectively. Furthermore, the photocatalytic ability of the synthesized materials to degrade different parabens (Methyl: MPB, Ethyl: EPB, and Benzyl: BPB) under visible radiation was evaluated. Under optimized conditions, the InS/WS heterostructure degraded 88.6, 90.4, and 95.8% of EPB, BPB, and MPB, respectively, in 90 min. The mechanism of photocatalysis was discussed in detail. MCF-7 cell viability was assessed and found to exhibit low mortality in InS/WS treated MPB aqueous solution. InS/WS heterostructure could improve the fabrication of more sulphide-based layered materials to combat environmental pollution.
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Affiliation(s)
- Abdulrahman G Alhamzani
- College of Science, Chemistry Department, Imam Mohammad Ibn Saud Islamic University, (IMSIU), Riyadh, 11623, Saudi Arabia
| | - Tarek A Yousef
- College of Science, Chemistry Department, Imam Mohammad Ibn Saud Islamic University, (IMSIU), Riyadh, 11623, Saudi Arabia; Department of Toxic and Narcotic Drug, Forensic Medicine, Mansoura Laboratory, Medicolegal Organization, Ministry of Justice, Egypt
| | - Mortaga M Abou-Krisha
- College of Science, Chemistry Department, Imam Mohammad Ibn Saud Islamic University, (IMSIU), Riyadh, 11623, Saudi Arabia; Department of Chemistry, South Valley University, Qena, 83523, Egypt
| | - K Yogesh Kumar
- Department of Chemistry, Faculty of Engineering and Technology, Jain University, Bangalore, 562112, India
| | - M K Prashanth
- Department of Chemistry, BNM Institute of Technology, Banashankari, Bangalore, 560070, India
| | - L Parashuram
- Department of Chemistry, Nitte Meenakshi Institute of Technology, Yelahanka, Bangalore, 560064 India
| | - Byong Hun Jeon
- Department of Earth Resources and Environmental Engineering, Hanyang University, 222, Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea.
| | - M S Raghu
- Department of Chemistry, New Horizon College of Engineering, Outer Ring Road, Bangalore, 560103, India.
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Ahmed E, Szulejko JE, Adelodun AA, Bhattacharya SS, Jeon BH, Kumar S, Kim KH. Sorptive process and breakthrough behavior of odorous volatile compounds on inert surfaces. Sci Rep 2018; 8:13118. [PMID: 30177843 PMCID: PMC6120927 DOI: 10.1038/s41598-018-31362-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 08/17/2018] [Indexed: 11/24/2022] Open
Abstract
The use of glass impinger is an important device for sampling and handling when measuring volatile organic compounds (SVOCs). Thus, it is important to check for possible analyte losses to the inner glass surface when carrying out sample analysis with the aid of impinger system. In this research, we evaluated the sorptive loss patterns of vapor-phase semi-volatile organic compounds [SVOCs (n = 10): acetic acid (ACA), propionic acid (PPA), i-butyric acid (IBA), n-butyric acid (BTA), i-valeric acid (IVA), n-valeric acid (VLA), phenol (PhAl), p-cresol (p-C), indole (ID), and skatole (SK)] on inert surfaces of an impinger in reference to sampling bags. The gaseous standard of these SVOCs (48–406 ppb) in polyester aluminum (PEA) bags was passed through an empty impinger in 1 L steps. The exiting SVOCs were collected on three-bed sorbent tubes for subsequent analysis by thermal desorption-gas chromatography-mass spectroscopy (TD-GC-MS). Impinger wall sorption capacities ranged from 2.0 to 21.0 ng cm−2. The 10% breakthrough adsorption capacities on the impinger wall for acids, phenols, and indoles ranged from 1.21 ± 0.15 to 5.39 ± 0.79, 0.92 ± 0.12 to 13.4 ± 2.25, and 4.47 ± 0.42 to 5.23 ± 0.35 ng cm−2, respectively. The observed sorptive patterns suggest that the sorptive losses of the volatile fatty acids, phenols, and indoles can occur very effectively at low ppb levels onto a glass surface.
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Affiliation(s)
- Ezaz Ahmed
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Korea
| | - Jan E Szulejko
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Korea
| | - Adedeji A Adelodun
- Department of Marine Science and Technology, School of Earth and Mineral Science, The Federal University of Technology, P.M.B. 704, Akure, Nigeria
| | | | - Byong Hun Jeon
- Department of Natural Resources and Environmental Engineering, Hanyang University, Seoul, 133-791, Korea.
| | - Sandeep Kumar
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Korea. .,Department of Bio and Nano Technology, Guru Jambheshwar University of Science and Technology, Hisar, Haryana, 125001, India.
| | - Ki-Hyun Kim
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Korea.
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Chung WJ, Nguyen DD, Bui XT, An SW, Banu JR, Lee SM, Kim SS, Moon DH, Jeon BH, Chang SW. A magnetically separable and recyclable Ag-supported magnetic TiO 2 composite catalyst: Fabrication, characterization, and photocatalytic activity. J Environ Manage 2018; 213:541-548. [PMID: 29478848 DOI: 10.1016/j.jenvman.2018.02.064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 02/12/2018] [Accepted: 02/16/2018] [Indexed: 05/24/2023]
Abstract
In this study, a magnetically separable, highly active, and recyclable photocatalyst was synthesized by physico-chemical incorporation of Ag, TiO2, and Fe3O4 into one structure. The physical and chemical properties of the catalysts were evaluated by X-ray diffraction, X-ray fluorescence spectrometry, scanning electron microscopy, field emission transmission electron microscopy, energy dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. The Ag-supported magnetic TiO2 composite demonstrated desirable properties and features such as a narrow band gap of 1.163 eV, modifiable structure, and high degradation efficiency. The activity and durability of the synthesized photocatalyst in the degradation of methyl orange (MO) in aqueous solutions under visible light irradiation and different experimental conditions were evaluated and compared to those of commercial TiO2 and Ag/TiO2 composites. It was found that the synthesized composite showed a much higher MO photodegradation efficiency than the other composites under visible light irradiation. Moreover, it exhibited a high photocatalytic activity and was recoverable and durable; its photocatalytic efficiency in MO removal was consistently higher than 93.1% after five reuses without any evident signs of deactivation. Thus, the developed photocatalyst is a very promising material for practical applications in environmental pollution remediation.
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Affiliation(s)
- Woo Jin Chung
- Department of Environmental Energy Engineering, Kyonggi University, 94 San, Iui-dong, Youngtong-gu, Suwon-si, Gyeonggi-do, 16227, Republic of Korea
| | - Dinh Duc Nguyen
- Department of Environmental Energy Engineering, Kyonggi University, 94 San, Iui-dong, Youngtong-gu, Suwon-si, Gyeonggi-do, 16227, Republic of Korea.
| | - Xuan Thanh Bui
- Faculty of Environment and Natural Resources, University of Technology, Vietnam National University, Ho Chi Minh City, Vietnam
| | - Sang Woo An
- Wizinnotek Co. Ltd, 452 Nohae-ro, Nowon-gu, Seoul, 01762, Republic of Korea
| | - J Rajesh Banu
- Department of Civil Engineering, Regional Campus of Anna University, Tirunelveli 627007, Tamil Nadu, India
| | - Sang Moon Lee
- Department of Environmental Energy Engineering, Kyonggi University, 94 San, Iui-dong, Youngtong-gu, Suwon-si, Gyeonggi-do, 16227, Republic of Korea
| | - Sung Su Kim
- Department of Environmental Energy Engineering, Kyonggi University, 94 San, Iui-dong, Youngtong-gu, Suwon-si, Gyeonggi-do, 16227, Republic of Korea
| | - Dea Hyun Moon
- Department of Environmental Energy Engineering, Kyonggi University, 94 San, Iui-dong, Youngtong-gu, Suwon-si, Gyeonggi-do, 16227, Republic of Korea
| | - Byong Hun Jeon
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Soon Woong Chang
- Department of Environmental Energy Engineering, Kyonggi University, 94 San, Iui-dong, Youngtong-gu, Suwon-si, Gyeonggi-do, 16227, Republic of Korea.
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Bhattacharya SS, Kim KH, Das S, Uchimiya M, Jeon BH, Kwon E, Szulejko JE. A review on the role of organic inputs in maintaining the soil carbon pool of the terrestrial ecosystem. J Environ Manage 2016; 167:214-227. [PMID: 26686074 DOI: 10.1016/j.jenvman.2015.09.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/24/2015] [Accepted: 09/27/2015] [Indexed: 06/05/2023]
Abstract
Among the numerous sources of greenhouse gases, emissions of CO2 are considerably affected by changes in the extent and type of land use, e.g., intensive agriculture, deforestation, urbanization, soil erosion, or wetland drainage. As a feasible option to control emissions from the terrestrial ecosystems, the scientific community has explored the possibility of enhancing soil carbon (C) storage capacity. Thus, restoration of damaged lands through conservation tillage, crop rotation, cover cropping, reforestation, sub-soiling of compacted lands, sustainable water management practices, and organic manuring are the major antidotes against attenuation of soil organic C (SOC) stocks. In this research, we focused on the effect of various man-made activities on soil biotic organics (e.g., green-, farm-yard manure, and composts) to understand how C fluxes from various sources contribute to the establishment of a new equilibrium in the terrestrial ecosystems. Although such inputs substitute a portion of chemical fertilizers, they all undergo activities that augment the rate and extent of decay to deplete the SOC bank. Here, we provide perspectives on the balancing factors that control the mineralization rate of organic matter. Our arguments are placed in the background of different land use types and their impacts on forests, agriculture, urbanization, soil erosion, and wetland destruction.
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Affiliation(s)
| | - Ki-Hyun Kim
- Department of Civil & Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 133-791, Republic of Korea.
| | - Subhasish Das
- Department of Environmental Science, Tezpur University, Assam 784028, India
| | - Minori Uchimiya
- USDA-ARS 1100 Robert E. Lee Blvd, New Orleans, LA 70124, USA
| | - Byong Hun Jeon
- Department of Natural Resources and Environmental Engineering, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Eilhann Kwon
- Department of Environment and Energy, Sejong University, Seoul 143-747, Republic of Korea
| | - Jan E Szulejko
- Department of Civil & Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 133-791, Republic of Korea
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Lee JM, Jeon BH, Kim J, Lee D. Microscopic mechanism underlying double-state lasing in an InAs/GaAs quantum dot laser diode elucidated using coupled rate equations and the spontaneous emission recorded from a window structure. Opt Express 2015; 23:31682-31690. [PMID: 26698961 DOI: 10.1364/oe.23.031682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We investigated the microscopic mechanism underlying the double-state lasing behavior (simultaneous lasing at the ground state [GS] and excited state [ES]) in InAs/GaAs quantum dot (QD) laser diodes. The ES and GS lasing processes that contributed to double-state lasing were examined experimentally and theoretically. Experiments were conducted in which spontaneous emission from a window of a QD laser diode was examined under lasing conditions, and numerical simulations were performed using a coupled rate equation model of the QD microstates. The findings showed that, when carrier relaxation from the ES to the GS was sufficiently slow, double-state lasing occurred. Additionally, ES lasing was found to arise not from the QD group undergoing GS lasing, but rather from another QD group in which the states were lower in energy and outside of the homogeneous bandwidth.
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Pandit S, Song JG, Kim YJ, Jeong JA, Jo JY, Lee GS, Kim HW, Jeon BH, Lee JU, Park JB. Attenuated benzodiazepine-sensitive tonic GABAA currents of supraoptic magnocellular neuroendocrine cells in 24-h water-deprived rats. J Neuroendocrinol 2014; 26:26-34. [PMID: 24313753 DOI: 10.1111/jne.12123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 11/05/2013] [Accepted: 12/01/2013] [Indexed: 11/26/2022]
Abstract
In supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs), γ-GABA, via activation of GABAA receptors (GABAA Rs), mediates persistent tonic inhibitory currents (Itonic ), as well as conventional inhibitory postsynaptic currents (IPSCs, Iphasic ). In the present study, we examined the functional significance of Itonic in SON MNCs challenged by 24-h water deprivation (24WD). Although the main characteristics of spontaneous IPSCs were similar in 24WD compared to euhydrated (EU) rats, Itonic , measured by bicuculline (BIC)-induced Iholding shifts, was significantly smaller in 24WD compared to EU rats (P < 0.05). Propofol and diazepam prolonged IPSC decay time to a similar extent in both groups but induced less Itonic in 24WD compared to EU rats, suggesting a selective decrease in GABAA receptors mediating Itonic over Iphasic in 24WD rats. THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol), a preferential δ subunit agonist, and L-655,708, a GABAA receptor α5 subunit selective imidazobenzodiazepine, caused a significantly smaller inward and outward shift in Iholding , respectively, in 24WD compared to EU rats (P < 0.05 in both cases), suggesting an overall decrease in the α5 subunit-containing GABAA Rs and the δ subunit-containing receptors mediating Itonic in 24WD animals. Consistent with a decrease in 24WD Itonic , bath application of GABA induced significantly less inhibition of the neuronal firing activity in 24WD compared to EU SON MNCs (P < 0.05). Taken together, the results of the present study indicate a selective decrease in GABAA Rs functions mediating Itonic as opposed to those mediating Iphasic in SON MNCs, demonstrating the functional significance of Itonic with respect to increasing neuronal excitability and hormone secretion in 24WD rats.
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Affiliation(s)
- S Pandit
- Department of Physiology, School of Medicine, Brain Research Institute, Chungnam National University, Jung-gu, Daejeon, Korea
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Liu KH, Kim MJ, Jeon BH, Shon JH, Cha IJ, Cho KH, Lee SS, Shin JG. Inhibition of human cytochrome P450 isoforms and NADPH-CYP reductase in vitro by 15 herbal medicines, including Epimedii herba. J Clin Pharm Ther 2006; 31:83-91. [PMID: 16476124 DOI: 10.1111/j.1365-2710.2006.00706.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE We evaluated the potential of 15 herbal medicines (HMs), commonly used in Korea, to inhibit the catalytic activities of several cytochrome P450 (CYP) isoforms and microsomal NADPH-CYP reductase. METHODS The abilities of 1-1000 microg/mL of freeze-dried aqueous extracts of 15 HMs to inhibit phenacetin O-deethylation (CYP1A2), tolbutamide 4-methylhydroxylation (CYP2C9), S-mephenytoin 4'-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), midazolam 1-hydroxylation (CYP3A4) and NADPH-CYP reductase were tested using human liver microsomes. RESULTS The HMs Epimedii herba, Glycyrrhizae radix and Leonuri herba inhibited one or more of the CYP isoforms or NADPH-CYP reductase. Of the three HMs, Epimedii herba extracts were the most potent inhibitors of several CYP isoforms (IC(50) 67.5 microg/mL for CYP2C19, 104.8 microg/mL for CYP2E1, 110.9 microg/mL for CYP2C9, 121.9 microg/mL for CYP3A4, 157.8 microg/mL for CYP2D6 and 168.7 microg/mL for CYP1A2) and NADPH-CYP reductase (IC(50) 185.9 microg/mL ). CONCLUSION These results suggest that some of the HMs used in Korea have the potential to inhibit CYP isoforms in vitro. Although the plasma concentrations of the active constituents of the HMs were not determined, some herbs could cause clinically significant interactions because the usual doses of those individual herbs are several grams of freeze-dried extracts. Controlled trials to test the significance of these results are necessary.
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Affiliation(s)
- K H Liu
- Department of Pharmacology and PharmacoGenomics Research Center, Inje University College of Medicine and Clinical Pharmacology Center, #633-165 Gaegum-Dong, Busanjin-Gu, Busan Paik Hospital, Busan 614-735, South Korea
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Lee IJ, Hwang SH, Jeon BH, Song SM, Kim JS, Paik KH, Kwon EK, Jin DK. Mutational analysis of the α-l-iduronidase gene in 10 unrelated Korean type I mucopolysaccharidosis patients: Identification of four novel mutations. Clin Genet 2004; 66:575-6. [PMID: 15521993 DOI: 10.1111/j.1399-0004.2004.00374.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The reactions of Fe(II) and other divalent metal ions including Zn, Co, Ni, and Cd on hematite were studied in single and competitive binary systems with high sorbate/sorbent ratios in 10 mM PIPES (pH 6.8) solution under strict anoxic conditions. Adsorbed Me(II) was defined as extractable by 0.5 N HCl within 20 h, and fixed Me(II) was defined as the additional amount that was extracted by 3.0 N HCl within 7 days. Binary systems contained Fe(II) plus a second metal ion. The extent of uptake of divalent metal ions by hematite was in order of Fe> or =Zn>Co> or =Ni>Cd. For all metals tested, there was an instantaneous adsorption followed by a relatively slow stage that continued for the next 1-5 days. This sequence occurred in both single and binary systems, and could have been due to a variety of sorption site types or due to slow conversion from outer- to inner-sphere surface complexes due to increasing surface charge. Sorption competition was observed between Fe(II) and the other metal ions. The displacement of Fe(II) by Me(II) was in order of Ni approximately Zn>Cd, and the displacement of Me(II) by Fe(II) was in order of Cd>Zn approximately Ni>Co. Fixed Fe(II) was in order of Fe+Co (20%)>Fe+Cd (6%)>Fe approximately Zn (4%)>Fe approximately Ni (4%) after 30 days. There was no fixation for the other metals in single or binary systems.
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Affiliation(s)
- Byong Hun Jeon
- Department of Civil and Environmental Engineering, The Pennsylvania State University, 212 Sackett Building, University Park, PA 16802-2450, USA.
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Kim HS, Kam KY, Ryu PD, Hong SJ, Jeon JS, Jeon BH, Kim KJ, Park JB. A gadolinium and pH-sensitive hyperpolarization-activated cation current in acutely isolated single neurones from Fasciola hepatica. Parasitology 2002; 125:423-30. [PMID: 12458826 DOI: 10.1017/s0031182002002299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Fasciola hepatica, a parasitic flatworm belonging to the Class Trematoda, is one of the first metazoan groups to possess a centralized nervous system. However, the electrophysiological properties of neurones in F. hepatica are largely unknown. In the present study, we acutely isolated viable neurones from F. hepatica and characterized their electrophysiological properties. A hyperpolarization-activated cation current was recorded in the cells using the whole-cell patch-clamp. The current was found to be activated slowly at membrane potentials negative to 0 mV and did not display any time-dependent inactivation. This current was reduced by 1 mM Gd3+ to the level of the leak current, while 3 mM of Cs+ had no effect. However, the current was inhibited by extracellular acidosis in the pH range 7.0-7.8, and the membrane potentials of these cells were depolarized by extracellular alkalosis in the pH range of 5.8 to 8.2. Gd3+ (1 mM), which inhibited the pH-sensitive hyperpolarization-activated cation current, also hyperpolarized the cells. In summary, we isolated single neurones from F. hepatica, and these were found to express a pH-sensitive hyperpolarization-activated cation current. This current may participate in the membrane depolarization of F. hepatica neurones during alkaline challenge.
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Affiliation(s)
- H S Kim
- Department of Physiology, College of Medicine, Chungnam National University, Taejon, Korea
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Angkeow P, Deshpande SS, Qi B, Liu YX, Park YC, Jeon BH, Ozaki M, Irani K. Redox factor-1: an extra-nuclear role in the regulation of endothelial oxidative stress and apoptosis. Cell Death Differ 2002; 9:717-25. [PMID: 12058277 DOI: 10.1038/sj.cdd.4401025] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2001] [Revised: 01/05/2002] [Accepted: 01/12/2002] [Indexed: 11/10/2022] Open
Abstract
The rac1 GTPase promotes oxidative stress through reactive oxygen species (ROS) production, whereas the DNA repair enzyme and transcriptional regulator redox factor-1 (ref-1) protects against cell death due to oxidative stimuli. However, the function of ref-1 in regulating intracellular oxidative stress, particularly that induced by rac1, has not been defined. We examined the role of ref-1 in vascular endothelial cell oxidative stress and apoptosis. Ref-1 was expressed in both the cytoplasm and nuclei of resting endothelial cells. Cytoplasmic ref-1 translocated to the nucleus with the oxidative trigger hypoxia/reoxygenation (H/R). Forced cytoplasmic overexpression of ref-1 suppressed H/R-induced oxidative stress (H(2)O(2) production), NF-kappaB activation, and apoptosis, and also mitigated rac1-regulated H(2)O(2) production and NF-kappaB transcriptional activity. We conclude that inhibition of oxidative stress is another mechanism by which ref-1 protects against apoptosis, and that this is achieved through modulation of cytoplasmic rac1-regulated ROS generation. This suggests a novel extra-nuclear function of ref-1.
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Affiliation(s)
- P Angkeow
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Kwon BK, Han KH, Han KY, Ju SM, Hwang SG, Jeon BH, Han DM, Kim WS. Molecular cloning of kpcA gene encoding a Kex2p-like endoprotease from Aspergillus nidulans. Mol Cells 2001; 12:142-7. [PMID: 11561725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
We cloned and sequenced a gene, kpcA (Kex2p-like proprotein convertase A), from a genomic library of Aspergillus nidulans. The kpcA gene encodes an 820-residue protein, named KpcA, which contains a putative subtilisin-like catalytic domain (residues 136-466) homologous to that of the subtilisin serine protease family. KpcA shows 56, 73, and 47% amino acid identities with Saccharomyces cerevisiae Kex2p, Aspergillus niger KexB, and mouse furin within the subtilisin-like catalytic domain, respectively. The sequences around the proposed active site Asp, His, and Ser residues of KpcA are similar to those of other Kex2p family members. The KpcA mRNA transcript with an expected size of approximately 2.8 kb was detected in A. nidulans. The substrate specificity of KpcA, expressed in CHO cells, is similar to that of A. niger KexB and yeast Kex2p. We conclude that KpcA is a resident Kex2p-like proprotein that processes endoprotease in A. nidulans.
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Affiliation(s)
- B K Kwon
- Division of Life Science, College of Natural Sciences, Wonkwang University, Iksan, Korea
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Jeon BH, Chang SJ, Kim JW, Hong YM, Yoon SY, Choe IS. Effect of high blood flow on the expression of endothelial constitutive nitric oxide synthase in rats with femoral arteriovenous shunts. Endothelium 2001; 7:243-52. [PMID: 11201522 DOI: 10.3109/10623320009072211] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The effect of high blood flow on the expression of endothelial nitric oxide synthase has been investigated in the femoral arteriovenous shunt (AVS) rats created by inserting U-shaped polyurethane tubes in the left femoral arteries and veins. Three days after inserting the femoral AVS, the mean aortic blood flow rate in the abdominal aorta of the AVS rats was about 2.0 times higher than that in the control rats (110.0 +/- 8.4 ml/min vs 52.7 +/- 2.7 ml/min, p < 0.001). The competitive reverse transcriptase-polymerase chain reaction (RT-PCR) data revealed that the mRNA expression level of the endothelial constitutive nitric oxide synthase (ecNOS) was increased in the aortas of the femoral AVS rats compared to that in the control rats. Western blot analysis using a monoclonal antibody against ecNOS revealed that the ecNOS protein levels were markedly increased in the aortas of femoral AVS rats, but ecNOS protein levels in aortas without endothelium were not significantly increased. Inducible nitric oxide synthase (iNOS) protein was not expressed in the aortic tissues with and without endothelium in the control rats. This iNOS expression was not increased by the high blood flow in the femoral AVS rats. These findings suggest that high blood flow could up-regulate the expression levels of ecNOS mRNA and proteins in femoral arteriovenous shunt rats.
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Affiliation(s)
- B H Jeon
- Department of Physiology, College of Medicine, Chungnam National University, Jung-gu, Taejon, Korea.
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Jeon BH, Kim CS, Kim HS, Park JB, Nam KY, Chang SJ. Effect of Korean red ginseng on blood pressure and nitric oxide production. Acta Pharmacol Sin 2000; 21:1095-100. [PMID: 11603282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
AIM To investigate the effect of crude saponin and nonsaponin fraction of Korean red ginseng (KRG) on the blood pressure and nitric oxide (NO) production in the conscious rats and cultured endothelial cell line, ECV 304 cells. METHODS Systolic blood pressure and heart rate were monitored in the conscious rats. Nitric oxide levels and the expression of nitric oxide synthase were measured by a spectrophotometric assay using Griess reagents and Western blotting, respectively. Nitric-oxide synthase activity was measured based on the conversion rate of [3H]arginine to [3H]citrulline. RESULTS Systolic blood pressure was decreased by crude saponin (100 mg/kg, i.v.) of KRG in the conscious control and one-kidney, one-clip Goldblatt hypertensive (1K, 1C-GBH) rats. The hypotensive effect induced by crude saponin of KRG reached maximum at 2-4 min and slowly recovered after 20 min to the initial level in both groups. Crude saponin of KRG induced tachycardia in the conscious rats but induced bradycardia in the anesthetized rats. In contrast to crude saponin of KRG, hypotensive effect induced by saponin-free fraction was minimal. Nitric oxide concentrations were increased by the treatment of crude saponin in conscious rats as well as in the cultured ECV 304 cells. The protein expression level of endothelial constitutive nitric-oxide synthase (eNOS) in the aorta of rats was not increased by crude saponin (100 mg/kg, i.p. for 3 d). However, nitric-oxide synthase activity was increased by crude saponin of KRG in the aortic homogenate of rats. CONCLUSION The hypotensive effect of red ginseng is mainly due to saponin fraction of KRG in the conscious rats, and this effect may be due to an increase in the nitric-oxide production by KRG.
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Affiliation(s)
- B H Jeon
- Department of Physiology, College of Medicine, Chungnam National University, 6 Munhwa-dong, Tung-gu, Taejon 301-131, Korea.
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Jeon BH, Kim CS, Park KS, Lee JW, Park JB, Kim KJ, Kim SH, Chang SJ, Nam KY. Effect of Korea red ginseng on the blood pressure in conscious hypertensive rats. Gen Pharmacol 2000; 35:135-41. [PMID: 11744235 DOI: 10.1016/s0306-3623(01)00096-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The change of blood pressure and heart rate after intravenous injection of Korea red ginseng (KRG) were studied in the conscious normotensive and one-kidney, one-clip Goldblatt hypertensive (1K, 1C-GBH) rats. Crude saponin (CS) of KRG (50, 100 mg/kg i.v.) induced a hypotensive effect and bradycardia in a dose-dependent manner in the anesthetized rats. On the other hand, CS of KRG (100 mg/kg) induced a hypotensive effect and reflex tachycardia in the conscious rats. Saponin-free fraction (SFF) of KRG did not affect them in the anesthetized normotensive rats (P>.05). The maximal hypotensive effect by CS of KRG in the conscious 1K, 1C-GBH hypertensive rats and L-nitroarginine methyl ester (L-NAME, 40 mg/kg)-treated conscious hypertensive rats was not different from that of conscious normotensive rats (Delta 31.6+/-6.3, Delta 27.5+/-5.8 vs. Delta 26.7+/-4.3 mmHg, P>.05). However, pretreatment of L-NAME significantly inhibited the reflex tachycardia by CS of KRG (70.8+/-7.0 vs. 30.6+/-15.0 bpm, P<.05). Hemolysate-sensitive nitric oxide (NO) current by the CS of KRG was greater than that of the SFF of KRG (651.9+/-128.2 pA for CS and 164.9+/-92.5 pA for SFF, P<.001). These findings suggest that KRG has a hypotensive effect and its effect may be due to saponin fraction of KRG in the conscious rats. The releasing effect of NO of KRG, like NO donor, may be partly contributed to the hypotensive effect of KRG.
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Affiliation(s)
- B H Jeon
- Department of Physiology, College of Medicine, Chungnam National University, 6 Munhwa-dong, Jung-gu, Taejon 301-131, South Korea. bhjeon@cnu. ac.kr
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Koo CM, Jeon BH, Chung IJ. The Effect of Poly(methyl vinyl ether-alt-maleic acid) Stabilizer on the Stability of Polyaniline-Poly(methyl vinyl ether-alt-maleic acid) Dispersions. J Colloid Interface Sci 2000; 227:316-321. [PMID: 10873315 DOI: 10.1006/jcis.2000.6898] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The polyaniline (PANI) dispersions have been prepared in acidic aqueous media by oxidative dispersion polymerization in the presence of a polymeric stabilizer. The polymeric stabilizer used in this study is the poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) which contains acid groups (-COOH). The PANI-PMVEMA particles have a uniform size and a spherical shape. The PANI-PMVEMA dispersions show almost no desorption of the PMVEMA, even though the sonication at 500 W for 20 min and the centrifugation at 500 rpm for 60 min are performed 10 times. The existence of the PMVEMA on the surface is confirmed by X-ray photoelectron spectroscopy. The dispersion stability of the PANI-PMVEMA dispersions is extensively influenced by zeta potential which was governed by the acid group (-COOH) of the PMVEMA on the PANI-PMVEMA particle surface. Copyright 2000 Academic Press.
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Affiliation(s)
- CM Koo
- Department of Chemical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Kusong-dong, Yusong-gu, Taejon, 305-701, South Korea
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Park CG, Chwae YJ, Kim JI, Lee JH, Hur GM, Jeon BH, Koh JS, Han JH, Lee SJ, Park JW, Kaslow DC, Strickman D, Roh CS. Serologic responses of Korean soldiers serving in malaria-endemic areas during a recent outbreak of Plasmodium vivax. Am J Trop Med Hyg 2000; 62:720-5. [PMID: 11304063 DOI: 10.4269/ajtmh.2000.62.720] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Anti-Pv200 antibody levels were assessed in samples from endemic areas of Plasmodium vivax malaria in the Republic of Korea (ROK), using an indirect enzyme-linked immunosorbent assay (ELISA) method. Asymptomatic carriers of P. vivax were detected using nested polymerase chain reaction (PCR) of blood samples. Anti-Pv200 antibody levels in 20 vivax malaria patients (optical density +/- standard deviation [OD +/- SD] values 1.85 +/- 0.29 of IgG isotype and 1.33 +/- 1.33 of IgM isotype) were markedly higher than those of uninfected, malaria-naive controls (0.08 +/- 0.16 of IgG isotype and 0.04 +/- 0.04 of IgM isotype). Antibody levels for 7 out of 8 soldiers with a recent malaria infection were sustained above the cut-off values for 4 months after successful treatment. Analysis of serum collected from 40 healthy, asymptomatic soldiers who had a P. vivax malaria attack within 3 months after our sampling, revealed 11 antibody-positive samples (27.5%), compared to 5 positive samples (12.5%) collected from a random selection of 40 soldiers. Among a larger pool of 1,713 soldiers who had served in high-risk areas for P. vivax transmission, 15% were antibody positive. Among 1,000 blood samples from asymptomatic soldiers who had served in the high-risk areas, 4 samples (0.4%) were parasite positive, as determined by nested PCR. Our results show that anti-Pv200 antibody levels can provide useful information in the late diagnosis of P. vivax malaria infection in a previously naive population and also in large seroepidemiologic studies. Furthermore, our results suggest that asymptomatic P. vivax carriers could be important in the current outbreak of malaria in Korea.
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Affiliation(s)
- C G Park
- Korean Armed Forces Central Medical Research Institute, Chumok-dong, Yuseong-gu, Taejeon, Republic of Korea.
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Abstract
To investigate whether alpha1-adrenoceptors are involved in pain behaviors in streptozotocin (STZ)-induced diabetic rats, we measured the effects of phenylephrine or prazosin on allodynia in the diabetic rats. Phenylephrine aggravated allodynia, while prazosin alleviated allodynia in the diabetic rats. We also measured alpha1-adrenoceptors gene expression or density of [3H]-prazosin binding sites in the dorsal root ganglia (DRG) and spinal cord in painful diabetic rats. Alpha1-adrenoceptors mRNA and density of [3H]prazosin binding sites were increased in the DRG of the diabetic rats, however there were no significant differences in alpha1-adrenoceptors expression in the spinal cord between the control and diabetic rats. These results suggest increased alpha1-adrenoceptors in the DRG may play a role in the pathogenesis of painful diabetic neuropathy.
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MESH Headings
- Adrenergic alpha-Antagonists/metabolism
- Adrenergic alpha-Antagonists/pharmacology
- Animals
- Diabetes Mellitus, Experimental/physiopathology
- Diabetic Neuropathies/physiopathology
- Ganglia, Spinal/chemistry
- Ganglia, Spinal/physiology
- Gene Expression/physiology
- Male
- Pain/physiopathology
- Pain Threshold/drug effects
- Prazosin/metabolism
- Prazosin/pharmacology
- RNA, Messenger/analysis
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, alpha-1/analysis
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Spinal Cord/chemistry
- Spinal Cord/physiology
- Tritium
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Affiliation(s)
- Y H Lee
- Department of Anatomy, College of Medicine, Chungnam National University, Taejon, Korea
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Choi CY, Lee YM, Kim YH, Park T, Jeon BH, Schulz RA, Kim Y. The homeodomain transcription factor NK-4 acts as either a transcriptional activator or repressor and interacts with the p300 coactivator and the Groucho corepressor. J Biol Chem 1999; 274:31543-52. [PMID: 10531357 DOI: 10.1074/jbc.274.44.31543] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
NK-4 (tinman) encodes an NK-2 class homeodomain transcription factor that is required for development of the Drosophila dorsal mesoderm, including heart. Genetic evidence suggests its important role in mesoderm subdivision, yet the properties of NK-4 as a transcriptional regulator and the mechanism of gene transcription by NK-4 are not completely understood. Here, we describe its properties as a transcription factor and its interaction with the p300 coactivator and the Groucho corepressor. We demonstrate that NK-4 can activate or repress target genes in cultured cells, depending on functional domains that are conserved between Drosophila melanogaster and Drosophila virilis NK-4 genes. Using GAL4-NK-4 fusion constructs, we have mapped a transcriptional activation domain (amino acids 1-110) and repression domains (amino acids 111-188 and the homeodomain) and found an inhibitory function for the homeodomain in transactivation by NK-4. Furthermore, we demonstrate that NK-4-dependent transactivation is augmented by the p300 coactivator and show that NK-4 physically interacts with p300 via the activation domain. In addition, cotransfection experiments indicate that the repressor activity of NK-4 is strongly enhanced by the Groucho corepressor. Using immunoprecipitation and in vitro pull-down assays, we show that NK-4 directly interacts with the Groucho corepressor, for which the homeodomain is required. Together, our results indicate that NK-4 can act as either a transcriptional activator or repressor and provide the first evidence of NK-4 interactions with the p300 coactivator and the Groucho corepressor.
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Affiliation(s)
- C Y Choi
- Laboratory of Molecular Cardiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, USA
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Hur GM, Ryu YS, Yun HY, Jeon BH, Kim YM, Seok JH, Lee JH. Hepatic ischemia/reperfusion in rats induces iNOS gene transcription by activation of NF-kappaB. Biochem Biophys Res Commun 1999; 261:917-22. [PMID: 10441525 DOI: 10.1006/bbrc.1999.1143] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
It has been known that many immediately early genes are expressed during ischemia/reperfusion (I/R) injury. Here, employing a model of hepatic I/R, we show that inducible nitric oxide synthase (iNOS) is induced via the activation of nuclear factor kappaB (NF-kappaB) after I/R in rat liver. When liver was subjected to ischemia followed by reperfusion, but not ischemia alone, an NF-kappaB complex composed of p50/p65 heterodimer and p50 homodimer was rapidly activated within 1 h and remained elevated for up to 3 h, and then tended to decline after 5 h of reperfusion. Also, the expression of iNOS mRNA was initiated after 1 h and continued to increase after 5 h of reperfusion during the time course studied. This upregulated iNOS mRNA expression coincides with increased iNOS enzyme activity and NF-kappaB binding activity after hepatic I/R. Administration of N-acetylcysteine (NAC, 20 mg/kg i.v. 10 min before reperfusion), an antioxidant, not only significantly inhibited the expression of iNOS mRNA but also blocked upregulated NF-kappaB binding activity after reperfused liver. These results suggest that NF-kappaB is activated by oxidative stress during hepatic I/R and may play a significant role in the induction of the iNOS gene.
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Affiliation(s)
- G M Hur
- College of Medicine, Chungnam National University, 6 Munhwa-dong, Jung-gu, Taejon, 301-131, Korea
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