1
|
Shirasawa H, Kumazawa Y, Sato W, Togashi K, Ono N, Fujishima A, Terada Y. P-346 First comparison of the egg freezing and storage cost between medical adaptation and social adaptation of Japan fertility hospitals and clinics based on institution's websites. Hum Reprod 2022. [DOI: 10.1093/humrep/deac107.329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Study question
In Japan, how much of freezing cost and the yearly storage cost of medical and social egg freezing for fertility preservation is clearly disclosed on the institution's website?
Summary answer
Of the 621 infertility treatment institutions, 146 listed egg freezing on their websites, 46 specified the freezing cost, and 71 specified the yearly storage cost.
What is known already
In Japan, from April 2022, standard assisted reproductive technology will be covered by insurance, but medical and social egg freezing will continue to be privately funded. Therefore, it is unclear how many facilities in Japan perform egg freezing. Furthermore, while the cost of freezing and yearly storage varies significantly from facility to facility, there has been no data comparing egg freezing among facilities in Japan or other countries. Therefore, we extracted data about freezing and storage cost from each institution's website and compared them for the first time.
Study design, size, duration
This study is a web-based survey in which a single board-certified specialist by Japan Society for Reproductive Medicine exhaustively browsed the websites of all 621 fertility treatment institutions in Japan in October 2021 and analyzed the implementation of egg freezing, freezing costs, and yearly storage costs of egg are clearly stated on the websites. The costs of drugs used for egg retrieval and ovarian stimulation were excluded.
Participants/materials, setting, methods
Of the 621 institutions, 88 institutions that clearly stated on their websites that they offer egg freezing for medical reasons were divided into a medical group, and 58 institutions that clearly stated that they offer egg freezing for only social reasons were divided into social group for statistical analysis. We compared the freezing and the yearly storage cost, respectively, whether it varies depending on the number of eggs or whether it is a fixed cost.
Main results and the role of chance
Of the 621 institutions, 146 (23.5%), 88 in the medical group and 58 in the social group, specified that they offer egg freezing. The percentages of clarification for freezing cost and yearly storage cost on the website were 27.3% and 30.7% in the medical group, 72.4%, and 75.9% in the social group, so the social group was higher in both cases (p < 0.01). The percentage of fixed costs for egg freezing was significantly lower in the social group (6/42, 14.3%) than in the medical group (9/24, 37.5%) (p < 0.05). The percentage of fixed costs for yearly storage cost was samely significantly lower in the social group (30/44, 68.2%) than in the medical group (25/27, 92.6%) (p < 0.05). The mean freezing cost/yearly storage cost was as follows for 1, 5, and 10 eggs. The medical group was (JPY45,527/JPY22,327, JPY65,179/JPY22,530, JPY90,311/JPY22,770), and the social group was (JPY56,822/JPY40,178, JPY88,429/JPY56,502, JPY136,550/JPY79,090), so the social group had the significantly highest amount of costs in each case. Note that JPY 10,000 is about EUR77.7. The most expensive clinic to store ten eggs was JPY500,000 (EUR3,883) per year, and the least university hospital was JPY 4,600 (EUR35.7) per year.
Limitations, reasons for caution
This survey was conducted by carefully browsing the facility's website, but since we did not confirm the information through questionnaires or e-mail, there is the possibility that the information may have been updated. Another limitation is that less than half of the medical groups list cost details on their websites.
Wider implications of the findings
This is the first report to analyze the cost of egg freezing in Japan using the institution's website. The rate of cost disclosure on the website is still low. Moreover, the costs of social freezing are significantly higher than medical reasons, but this may change with the insurance of ART.
Trial registration number
not applicable
Collapse
Affiliation(s)
- H Shirasawa
- Akita University, Department of Obstetrics and Gynecology, Akita city- Akita prefecture , Japan
| | - Y Kumazawa
- Akita University, Department of Obstetrics and Gynecology, Akita city- Akita prefecture , Japan
| | - W Sato
- Akita University, Department of Obstetrics and Gynecology, Akita city- Akita prefecture , Japan
| | - K Togashi
- Akita University, Department of Obstetrics and Gynecology, Akita city- Akita prefecture , Japan
| | - N Ono
- Akita University, Department of Obstetrics and Gynecology, Akita city- Akita prefecture , Japan
| | - A Fujishima
- Akita University, Department of Obstetrics and Gynecology, Akita city- Akita prefecture , Japan
| | - Y Terada
- Akita University, Department of Obstetrics and Gynecology, Akita city- Akita prefecture , Japan
| |
Collapse
|
2
|
Hirakawa T, Goto M, Takahashi K, Iwasawa T, Fujishima A, Makino K, Shirasawa H, Sato W, Sato T, Kumazawa Y, Terada Y. Na+/K+ ATPase α1 and β3 subunits are localized to the basolateral membrane of trophectoderm cells in human blastocysts. Hum Reprod 2022; 37:1423-1430. [PMID: 35640043 PMCID: PMC9247425 DOI: 10.1093/humrep/deac124] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/09/2022] [Indexed: 11/25/2022] Open
Abstract
STUDY QUESTION Is there a relation between specific Na+/K+ ATPase isoform expression and localization in human blastocysts and the developmental behavior of the embryo? SUMMARY ANSWER Na+/K+ ATPase α1, β1 and β3 are the main isoforms expressed in human blastocysts and no association was found between the expression level of their respective mRNAs and the rate of blastocyst expansion. WHAT IS KNOWN ALREADY In mouse embryos, Na+/K+ ATPase α1 and β1 are expressed in the basolateral membrane of trophectoderm (TE) cells and are believed to be involved in blastocoel formation (cavitation). STUDY DESIGN, SIZE, DURATION A total of 20 surplus embryos from 11 patients who underwent IVF and embryo transfer at a university hospital between 2009 and 2018 were analyzed. PARTICIPANTS/MATERIALS, SETTING, METHODS After freezing and thawing Day 5 human blastocysts, their developmental behavior was observed for 24 h using time-lapse imaging, and the expression of Na+/K+ ATPase isoforms was examined using quantitative RT-PCR (RT-qPCR). The expressed isoforms were then localized in blastocysts using fluorescent immunostaining. MAIN RESULTS AND THE ROLE OF CHANCE RT-qPCR results demonstrated the expression of Na+/K+ ATPase α1, β1 and β3 isoforms in human blastocysts. Isoforms α1 and β3 were localized to the basolateral membrane of TE cells, and β1 was localized between TE cells. A high level of β3 mRNA expression correlated with easier hatching (P = 0.0261). LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION The expression of mRNA and the localization of proteins of interest were verified, but we have not been able to perform functional analysis. WIDER IMPLICATIONS OF THE FINDINGS Of the various Na+/K+ ATPase isoforms, expression levels of the α1, β1 and β3 mRNAs were clearly higher than other isoforms in human blastocysts. Since α1 and β3 were localized to the basolateral membrane via fluorescent immunostaining, we believe that these subunits contribute to the dilation of the blastocoel. The β1 isoform is localized between TE cells and may be involved in tight junction formation, as previously reported in mouse embryos. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the JSPS KAKENHI (https://www.jsps.go.jp/english/index.html), grant number 17K11215. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors have no conflicts of interest.
Collapse
Affiliation(s)
- T Hirakawa
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - M Goto
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - K Takahashi
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - T Iwasawa
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - A Fujishima
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - K Makino
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - H Shirasawa
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - W Sato
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - T Sato
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - Y Kumazawa
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| | - Y Terada
- Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, Akita, Japan
| |
Collapse
|
3
|
Hunge YM, Yadav AA, Dhodamani AG, Suzuki N, Terashima C, Fujishima A, Mathe VL. Enhanced photocatalytic performance of ultrasound treated GO/TiO 2 composite for photocatalytic degradation of salicylic acid under sunlight illumination. Ultrason Sonochem 2020; 61:104849. [PMID: 31710997 DOI: 10.1016/j.ultsonch.2019.104849] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 05/27/2023]
Abstract
The current research work deals with the preparation of TiO2 and GO/TiO2 composite by simple, chemical, cost effective hydrothermal method. Graphene oxide (GO) is prepared by modified Hummer's method. Dispersion of GO is achieved by an ultrasonic cleaning bath for 1 h. using a power of 200 W and at a frequency of 40 kHz. The prepared catalyst material is characterized by different characterization techniques. XRD study confirms the prepared material is polycrystalline in nature. The synthesized TiO2 and GO/TiO2 photocatalyst materials are used to study the photocatalytic degradation of salicylic acid under sunlight illumination. GO/TiO2 composite shows superior photocatalytic activity than TiO2. GO/TiO2 composite shows 57% degradation of salicylic acid. Mineralization of salicylic acid is studied using chemical oxygen demand.
Collapse
Affiliation(s)
- Y M Hunge
- Photocatalysis International Research Centre, Tokyo University of Science, Yazamaki, Noda 278-8510, Chiba, Japan.
| | - A A Yadav
- Photocatalysis International Research Centre, Tokyo University of Science, Yazamaki, Noda 278-8510, Chiba, Japan
| | - A G Dhodamani
- Department of Chemistry, Shivaji University, Kolhapur 416004, India
| | - N Suzuki
- Photocatalysis International Research Centre, Tokyo University of Science, Yazamaki, Noda 278-8510, Chiba, Japan
| | - C Terashima
- Photocatalysis International Research Centre, Tokyo University of Science, Yazamaki, Noda 278-8510, Chiba, Japan
| | - A Fujishima
- Photocatalysis International Research Centre, Tokyo University of Science, Yazamaki, Noda 278-8510, Chiba, Japan
| | - V L Mathe
- Department of Physics, Savitribai Phule Pune University, Pune 411007, India.
| |
Collapse
|
4
|
Raja R, Sudhagar P, Devadoss A, Terashima C, Shrestha LK, Nakata K, Jayavel R, Ariga K, Fujishima A. Pt-free solar driven photoelectrochemical hydrogen fuel generation using 1T MoS2 co-catalyst assembled CdS QDs/TiO2 photoelectrode. Chem Commun (Camb) 2015; 51:522-5. [DOI: 10.1039/c4cc07304e] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, Pt-free solar hydrogen generation was achieved using TiO2–CdS photoelectrodes with a metallic-type 1T MoS2 co-catalyst in a back-to-back electrode architecture.
Collapse
Affiliation(s)
- R. Raja
- Centre for Nanoscience and Technology
- Anna University
- Chennai
- India
| | - P. Sudhagar
- Photocatalysis International Research Center (PIRC)
- Research Institute for Science & Technology
- Tokyo University of Science
- Chiba 278-8510
- Japan
| | - Anitha Devadoss
- Photocatalysis International Research Center (PIRC)
- Research Institute for Science & Technology
- Tokyo University of Science
- Chiba 278-8510
- Japan
| | - C. Terashima
- Photocatalysis International Research Center (PIRC)
- Research Institute for Science & Technology
- Tokyo University of Science
- Chiba 278-8510
- Japan
| | - L. K. Shrestha
- International Center for Materials Nanoarchitectonics (WPI-MANA)
- National Institute for Materials Science (NIMS)
- Ibaraki 305-0044
- Japan
| | - K. Nakata
- Photocatalysis International Research Center (PIRC)
- Research Institute for Science & Technology
- Tokyo University of Science
- Chiba 278-8510
- Japan
| | - R. Jayavel
- Centre for Nanoscience and Technology
- Anna University
- Chennai
- India
| | - K. Ariga
- International Center for Materials Nanoarchitectonics (WPI-MANA)
- National Institute for Materials Science (NIMS)
- Ibaraki 305-0044
- Japan
| | - A. Fujishima
- Photocatalysis International Research Center (PIRC)
- Research Institute for Science & Technology
- Tokyo University of Science
- Chiba 278-8510
- Japan
| |
Collapse
|
5
|
Devadoss A, Sudhagar P, Das S, Lee SY, Terashima C, Nakata K, Fujishima A, Choi W, Kang YS, Paik U. Synergistic metal-metal oxide nanoparticles supported electrocatalytic graphene for improved photoelectrochemical glucose oxidation. ACS Appl Mater Interfaces 2014; 6:4864-71. [PMID: 24606811 DOI: 10.1021/am4058925] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report the fabrication of graphene-WO3-Au hybrid membranes and evaluate their photocatalytic activity towards glucose oxidase mediated enzymatic glucose oxidation. The dual-functionality of gold nanoparticles in the reinforcement of visible light activity of graphene-WO3 membranes and improving the catalytic activity of immobilized enzymes for unique photoelectrochemical sensing application is demonstrated. This work provides new insights into the fabrication of light-sensitive hybrid materials and facilitates their application in future.
Collapse
Affiliation(s)
- Anitha Devadoss
- Department of Materials Science Engineering, §WCU Department of Energy Engineering, Hanyang University , Seoul 133-791, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Manivannan A, Fujishima A, Rao GVS. Investigation of Current Doubling Reactions at SiC/Aqueous Electrolyte Junction in Relation to the Band Energetics. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/bbpc.198800362] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
7
|
Choi J, Sudhagar P, Lakshmipathiraj P, Lee JW, Devadoss A, Lee S, Song T, Hong S, Eito S, Terashima C, Han TH, Kang JK, Fujishima A, Kang YS, Paik U. Three-dimensional Gd-doped TiO2 fibrous photoelectrodes for efficient visible light-driven photocatalytic performance. RSC Adv 2014. [DOI: 10.1039/c3ra46851h] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Demonstration of the role of electrode geometry on in situ Gd-doping and their effects in the photocatalytic activity.
Collapse
Affiliation(s)
- Junghyun Choi
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - P. Sudhagar
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
- Center for Next Generation Dye-sensitized Solar Cells
- Hanyang University
| | - P. Lakshmipathiraj
- Photocatalysis International Research Center
- Tokyo University of Science
- Chiba 278-8510, Japan
| | - Jung Woo Lee
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - Anitha Devadoss
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - Sangkyu Lee
- Department of Materials Science and Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - Taeseup Song
- Department of Materials Science and Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - Seungki Hong
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - S. Eito
- Flucto-Order Functions Research Team
- RIKEN-ASI
- Saitama 351-0198, Japan
| | - C. Terashima
- Photocatalysis International Research Center
- Tokyo University of Science
- Chiba 278-8510, Japan
| | - Tae Hee Han
- Department of Organic and Nano Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - Jeung Ku Kang
- Graduate School of EEWS
- Department of Materials Science and Engineering
- NanoCentury KI, KAIST
- Daejeon 305-701, Korea
| | - A. Fujishima
- Photocatalysis International Research Center
- Tokyo University of Science
- Chiba 278-8510, Japan
| | - Yong Soo Kang
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
- Center for Next Generation Dye-sensitized Solar Cells
- Hanyang University
| | - Ungyu Paik
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
| |
Collapse
|
8
|
Sudhagar P, Devadoss A, Song T, Lakshmipathiraj P, Han H, Lysak VV, Terashima C, Nakata K, Fujishima A, Paik U, Kang YS. Enhanced photocatalytic performance at a Au/N–TiO2hollow nanowire array by a combination of light scattering and reduced recombination. Phys Chem Chem Phys 2014; 16:17748-55. [DOI: 10.1039/c4cp02009j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Maximizing the Au nanoparticle decoration on TiO2nanowire through nitrogen doping for simultaneous enhancement in visible light scattering and electron–hole charge separation.
Collapse
Affiliation(s)
- P. Sudhagar
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
- Photocatalysis International Research Center
- Tokyo University of Science
| | - Anitha Devadoss
- Photocatalysis International Research Center
- Tokyo University of Science
- Noda, Japan
- Department of Materials Science and Engineering
- Hanyang University
| | - Taeseup Song
- Department of Materials Science and Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - P. Lakshmipathiraj
- Photocatalysis International Research Center
- Tokyo University of Science
- Noda, Japan
| | - Hyungkyu Han
- Department of Materials Science and Engineering
- Hanyang University
- Seoul 133-791, Korea
| | - Volodymyr V. Lysak
- Semiconductor Physics Research Center
- School of Semiconductor and Chemical Engineering
- Chonbuk National University
- Jeonju 561-756, Korea
| | - C. Terashima
- Photocatalysis International Research Center
- Tokyo University of Science
- Noda, Japan
| | - Kazuya Nakata
- Photocatalysis International Research Center
- Tokyo University of Science
- Noda, Japan
| | - A. Fujishima
- Photocatalysis International Research Center
- Tokyo University of Science
- Noda, Japan
| | - Ungyu Paik
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
- Department of Materials Science and Engineering
- Hanyang University
| | - Yong Soo Kang
- Department of Energy Engineering
- Hanyang University
- Seoul 133-791, Korea
| |
Collapse
|
9
|
Emeline AV, Zhang X, Murakami T, Fujishima A. Activity and selectivity of photocatalysts in photodegradation of phenols. J Hazard Mater 2012; 211-212:154-60. [PMID: 22178282 DOI: 10.1016/j.jhazmat.2011.11.078] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 11/21/2011] [Accepted: 11/23/2011] [Indexed: 05/23/2023]
Abstract
Photodegradation of phenol and 4-chlorophenol over six different TiO(2) samples was tested in order to establish whether an interconnection between the activity and selectivity of photocatalysts exists. The obtained experimental data were analyzed using correlation analysis. Some correlations between the activity in phenol(s) photodegradation and selectivity toward formation of primary intermediate products were established. The type of correlations depends on the type of studied photoreactions. The discussion of the observed correlations between the activity and selectivity of photocatalysts is given in terms of the difference of surface concentrations of electrons and holes and corresponding surface active sites which might be dependent on the types of dominating surface faces. On the basis of the obtained results of correlation analysis it was assumed that a higher activity of photocatalysts could be achieved provided that both reduction and oxidation reaction pathways occur with equally high efficiency.
Collapse
Affiliation(s)
- A V Emeline
- Department of Photonics, V.A. Fock Institute of Physics, Saint-Petersburg State University, Ulianovskaia Str. 1, Petrodvoretz, St.-Petersburg 198504, Russia. emeline
| | | | | | | |
Collapse
|
10
|
Yamamura K, Ohga S, Nishiyama K, Doi T, Tsutsumi Y, Ikeda K, Fujishima A, Takada H, Hara T. Recurrent atrial fibrillation after high-dose methylprednisolone therapy in a girl with lupus-associated hemophagocytic syndrome. Lupus 2011; 20:871-5. [DOI: 10.1177/0961203310392429] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hemophagocytic syndrome (HPS) is a serious complication of systemic lupus erythematosus (SLE). A 15-year-old female with lupus-nephritis developed HPS. Bone marrow study showed florid thrombophagocytosis. There was no associated infection. High-dose methylprednisolone therapy ameliorated HPS. However, atrial fibrillation (Af) repeated after the infusion and required direct-current cardioversion. No underlying diseases were found in the heart and endocrine system. Chest roentgenogram and echocardiography were normal. Electrocardiogram showed slightly prolonged PR interval in sinus rhythm. Af occurred at high circulating levels of interferon-γ and interleukin (IL)-10, but not IL-6, IL-2, tumor necrosis factor-α, C-reactive protein or catecholamines. This is the first observation that high-dose corticosteroid induced Af in a case of lupus-HPS. Af is unusual in SLE children without cardiac disease, while conduction defect occurs associated with lupus-myocarditis. Lupus-HPS may be an aggressive SLE subset with cardiac involvement. High-dose corticosteroid infusion controls lupus activity, but could disclose the cardiac stress in lupus-HPS patients.
Collapse
Affiliation(s)
- K Yamamura
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - S Ohga
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - K Nishiyama
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - T Doi
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Y Tsutsumi
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - K Ikeda
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - A Fujishima
- Division of Clinical Laboratories, Kyushu University Hospital, Fukuoka, Japan
| | - H Takada
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - T Hara
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| |
Collapse
|
11
|
|
12
|
|
13
|
|
14
|
Patel K, Yamagata S, Fujishima A, Loo BH, Kato T. Photo-sinking Phenomenon: Photodecomposition Rate of Silane Bonded on TiO2 Powders. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19910950211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
15
|
Döring H, Hashimoto K, Fujishima A. TiO2 Thin Films Prepared by Pulsed Beam Chemical Vapor Deposition from Titanium Tetraisopropoxide and Water. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19920960416] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
16
|
|
17
|
Amemiya T, Itoh K, Fujishima A. Spectroscopic and Electrochemical Behavior of Polypyrrole Films Incorporating Methylene Blue, and Their Enhancement in Electrochromism. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19890930607] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
18
|
Miyamoto M, Tanaka Y, Furuta M, Kondo T, Fujishima A, Honda K. Isolation and dispersion of reduced metal particles using the surface dipole moment of F-terminated diamond electrodes. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2008.12.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
19
|
Hirose Y, Murosaki S, Yamamoto Y, Muroyama K, Miwa Y, Fujishima A, Lynch B. Safety studies of LP20 powder produced from heat-killed Lactobacillus plantarum L-137. Regul Toxicol Pharmacol 2009; 54:214-20. [PMID: 19328216 DOI: 10.1016/j.yrtph.2009.03.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 03/18/2009] [Accepted: 03/19/2009] [Indexed: 01/08/2023]
Abstract
The safety of LP20 and its prototype, a powder, with potential use in food, produced from a mixture of dextrin and heat-killed Lactobacillus plantarum L-137, was assessed in an acute study in mice, and in an in vitro bacterial reverse mutation assay, an in vitro chromosome aberration assay, and an in vivo mouse micronucleus assay. LP20 prototype was not acutely toxic when administered to male and female Slc:ICR mice by single gavage at 2000mg/kg bw. Dosing was not associated with mortality, clinical signs, changes in bodyweight, or macroscopic abnormalities. The LD(50) in mice was greater than 2000mg/kg bw. There was no evidence of genotoxicity of LP20 in the Ames assay (0-5000microg/plate) or in the in vitro chromosome aberration assay with Chinese hamster lung fibroblasts (0-5000microg/mL). Administration of two consecutive daily doses of 500, 1000, or 2000mg/kg bw by gavage to male Crlj:CD-1 mice was not associated with an increased incidence of micronuclei and did not alter the ratio of polychromatic to normochromatic erythrocytes. These studies show that LP20 powder is not acutely toxic and is without genotoxic activity both in vitro and in vivo.
Collapse
Affiliation(s)
- Y Hirose
- Food Science Research Center, House Wellness Foods Corp., Imoji 3-20, Itami, Hyogo 664-0011, Japan
| | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
Ceramic restorations with resin-based adhesive systems have been the focus of recent attention in clinical dentistry. Yttrium-oxide-partially-stabilized zirconia (YPSZ) ceramics have optimized physical properties and exhibit favorable fracture toughness, though their bonding properties are problematic. Although functional phosphate monomers and silica-coating by tribochemical modification were expected to improve the bonding properties between YPSZ ceramics and resin-based adhesives, these two methods remain controversial. This study evaluated the efficiency of silica-coating by tribochemical modification of YPSZ ceramics. The application of phosphate monomer and a silane coupling agent on silica-coated YPSZ was also investigated. The silica-coating of YPSZ ceramics by tribochemical modification was not efficient, given the higher mechanical toughness of the densely sintered ceramics. Stable shear bond strength was achieved on silica-coated YPSZ ceramics with the cooperative interaction of phosphate monomer and silane coupling.
Collapse
Affiliation(s)
- R Tanaka
- Department of Oral Biomaterials and Technology, Showa University, Shinagawa-ku, Tokyo 142-8555, Japan.
| | | | | | | | | |
Collapse
|
21
|
Gu Z, Sato O, Iyoda T, Hashimoto K, Fujishima A. Syntheses and Magnetic Properties of Dye Included Organometallic Magnets: DAMS[MCr(ox)3]. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259608042279] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Zhongze Gu
- a Department of Applied Chemistry , The University of Tokyo , 7-3-1 Kongo Bunkyo-Ku, Tokyo , 113 , Japan
| | - O. Sato
- b Kanagawa Academy of Science and Technology, in Tokyo Institute of Polytechnics , 1583 liyama, Atsugi, Kanagawa , 243-02 , Japan
| | - T. Iyoda
- b Kanagawa Academy of Science and Technology, in Tokyo Institute of Polytechnics , 1583 liyama, Atsugi, Kanagawa , 243-02 , Japan
| | - K. Hashimoto
- a Department of Applied Chemistry , The University of Tokyo , 7-3-1 Kongo Bunkyo-Ku, Tokyo , 113 , Japan
- b Kanagawa Academy of Science and Technology, in Tokyo Institute of Polytechnics , 1583 liyama, Atsugi, Kanagawa , 243-02 , Japan
| | - A. Fujishima
- a Department of Applied Chemistry , The University of Tokyo , 7-3-1 Kongo Bunkyo-Ku, Tokyo , 113 , Japan
| |
Collapse
|
22
|
Emeline AV, Zhang X, Jin M, Murakami T, Fujishima A. Application of a “Black Body” Like Reactor for Measurements of Quantum Yields of Photochemical Reactions in Heterogeneous Systems. J Phys Chem B 2006; 110:7409-13. [PMID: 16599518 DOI: 10.1021/jp057115f] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report for the first time an experimental application of the concept of a "black body" like reactor to measure quantum yields (Phi) of photochemical reactions in liquid-solid heterogeneous systems. A major advantage of this new method is its simplicity since the fractions of reflected and transmitted light are negligible due to reactor geometry and high optical density of the heterogeneous systems. The average quantum yield of a test reaction (phenol photodegradation) over TiO(2) (Degussa P25) as determined by this method was 0.14, identical to the quantum yield measured earlier for this same reaction under similar conditions by Salinaro and Serpone. We also report the quantum yield of phenol photodegradation over N-doped TiO(2) during photoexcitation at the fundamental absorption band (lambda = 365 nm; Phi = 0.12) and at the N-doping induced extrinsic absorption band (lambda = 436 nm; Phi = 0.08) of the photocatalyst.
Collapse
Affiliation(s)
- A V Emeline
- Kanagawa Academy of Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, Japan
| | | | | | | | | |
Collapse
|
23
|
Honda K, Yamaguchi Y, Yamanaka Y, Yoshimatsu M, Fukuda Y, Fujishima A. Hydroxyl radical-related electrogenerated chemiluminescence reaction for a ruthenium tris(2,2′)bipyridyl/co-reactants system at boron-doped diamond electrodes. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2005.05.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
24
|
Manivannan A, Ramakrishnan L, Seehra M, Granite E, Butler J, Tryk D, Fujishima A. Mercury detection at boron doped diamond electrodes using a rotating disk technique. J Electroanal Chem (Lausanne) 2005. [DOI: 10.1016/j.jelechem.2004.12.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
25
|
Honda K, Noda T, Yoshimura M, Nakagawa K, Fujishima A. Microstructural Heterogeneity for Electrochemical Activity in Polycrystalline Diamond Thin Films Observed by Electrogenerated Chemiluminescence Imaging. J Phys Chem B 2004. [DOI: 10.1021/jp040395z] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - A. Fujishima
- Kanagawa Advanced Science and Technology (KAST), 3-2-1, Sakato, Takastu-ku, Kawasaki-shi, Kanagawa, 213-0012, Japan
| |
Collapse
|
26
|
Duo I, Levy-Clement C, Fujishima A, Comninellis C. Electron Transfer Kinetics on Boron-Doped Diamond Part I: Influence of Anodic Treatment. J APPL ELECTROCHEM 2004. [DOI: 10.1023/b:jach.0000040525.76264.16] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
27
|
Olivia H, Sarada B, Honda K, Fujishima A. Continuous glucose monitoring using enzyme-immobilized platinized diamond microfiber electrodes. Electrochim Acta 2004. [DOI: 10.1016/j.electacta.2003.10.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
28
|
|
29
|
Xue B, Wang H, Hu Y, Li H, Wang Z, Meng Q, Huang X, Sato O, Chen L, Fujishima A. An alternative ionic liquid based electrolyte for dye-sensitized solar cells. Photochem Photobiol Sci 2004; 3:918-9. [PMID: 15480481 DOI: 10.1039/b412647e] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [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: 11/21/2022]
Abstract
An ionic liquid based, environmentally friendly electrolyte LiI(C(2)H(5)OH)(4)-I(2) was used as the electrolyte to fabricate dye-sensitized solar cells (DSSC) with energy conversion efficiency of 4.9% under AM 1.5 (100 mW cm(-2)) irradiation.
Collapse
Affiliation(s)
- Bofei Xue
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, PR China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Ivandini TA, Sarada BV, Terashima C, Rao TN, Tryk DA, Ishiguro H, Kubota Y, Fujishima A. Gradient liquid chromatography of leucine-enkephalin peptide and its metabolites with electrochemical detection using highly boron-doped diamond electrode. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 791:63-72. [PMID: 12798166 DOI: 10.1016/s1570-0232(03)00204-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [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: 10/27/2022]
Abstract
Boron-doped diamond thin film (BDD) electrodes have been used to study the oxidation reactions and to detect leucine-enkephalinamide (LEA) and its metabolites, tyrosine (T), tyrosyl-alanine (TA), tyrosyl-alanine-glycine (TAG) and leucine-enkephalin (LE) using cyclic voltammetry (CV), flow-injection analysis (FIA), and gradient liquid chromatography (LC) with amperometric detection. At diamond electrodes, well-defined and highly reproducible cyclic voltammograms were obtained with signal-to-background (S/B) ratios 5-10 times higher than those observed for glassy carbon (GC) electrodes. The analytical peaks of LC for LEA and its metabolites were well resolved. No deactivation of BDD electrodes was found after several experiments with standard as well as plasma samples, indicating high stability of the electrode. Calibration curves were linear over a wide range from 0.06 to 30 microM with regression coefficients of 0.999 for all compounds. The limits of detection obtained based on a signal-to-noise ratio of 3:1 were 3, 2.2, 2.7, 20 and 11 nM for T, TA, TAG, LE and LEA, respectively. These values were at least one order lower than those obtained at GC electrodes, which has given limits of detection of 22.88, 20.64, 89.57, 116.04 and 75.67 for T, TA, TAG, LE and LEA, respectively. Application of this method to real samples was demonstrated and validated using rabbit serum samples. This work shows the promising use of conducting diamond as an amperometric detector in gradient LC, especially for the analysis of enkephalinamide and its metabolites.
Collapse
Affiliation(s)
- T A Ivandini
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
Boron-doped diamond (BDD) electrodes have been examined for the electrochemical oxidation of underivatized-nucleic acids in terms of single stranded and double stranded DNA. Cyclic voltammetry and square wave voltammetry have been used to study the oxidation reactions and to detect DNA without derivatization or hydrolysis steps. At the diamond electrode, at least two well-defined voltammetric peaks were observed for both single stranded and double stranded DNA. Diamond electrode is the first material to show a well-defined voltammetric peaks for adenine group oxidation directly in the helix structure of nucleic acid due to its wide potential window. For single stranded DNA, a third peak, related to the pyrimidine group oxidation was also observed. As-deposited diamond film with predominantly hydrogen-terminated surface exhibited superior performance over oxygen-terminated diamond in terms of sensitivity. However, by optimizing the ionic strength, sensitivity of O-terminated films could be improved. Linear calibration results have shown linearity of current with concentration in the range 0.1-8 microg mL(-1) for both guanine and adenine residues at as-deposited BDD. Detection limits (S/N = 3) of 3.7 and 10 ng mL(-1) for adenine and guanine residue in single stranded DNA, respectively, and 5.2 and 10 ng mL(-1) for adenine and guanine residue in double stranded DNA, respectively, were observed. This work shows the promising use of diamond as an electrochemical detector for direct detection of nucleic acids. The results also show the possibility of using the oxidation peak current of adenine group that is more sensitive for the direct detection of nucleicacids.
Collapse
Affiliation(s)
- T A Ivandini
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | | | | | | |
Collapse
|
32
|
Liu HW, Matsuda K, Gu ZZ, Takahashi K, Cui AL, Nakajima R, Fujishima A, Sato O. Reversible valence tautomerism induced by a single-shot laser pulse in a cobalt-iron Prussian blue analog. Phys Rev Lett 2003; 90:167403. [PMID: 12732007 DOI: 10.1103/physrevlett.90.167403] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2002] [Indexed: 05/24/2023]
Abstract
Reversible valence tautomeric conversion induced by a single-shot laser pulse (8 ns duration) with a photon excitation energy of 2.38 eV has been observed in Na0.36Co1.32Fe(CN)(6).5.6H(2)O. A photoswitching process with accompanying magnetization and color changes was successfully achieved within the pulse duration at high temperature (above 200 K) in a thermal hysteresis loop. This unusual photoeffect originates from an optical charge transfer between Fe and Co atoms and evolves due to a cooperative interaction among the local photoexcited sites.
Collapse
Affiliation(s)
- H W Liu
- Kanagawa Academy of Science and Technology, KSP Building East 412, 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa 213-0012, Japan
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Terashima C, Rao TN, Sarada BV, Kubota Y, Fujishima A. Direct electrochemical oxidation of disulfides at anodically pretreated boron-doped diamond electrodes. Anal Chem 2003; 75:1564-72. [PMID: 12705586 DOI: 10.1021/ac020583q] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anodically oxidized diamond electrodes have been used to oxidize disulfides, thiols, and methionine in aqueous acidic media and tested for amperometric detection of these compounds after chromatographic separation. Cyclic voltammetric signals for 1 mM glutathione disulfide (GSSG) were observed at 1.39 and 1.84 V vs SCE, the values being less positive than those of its as-deposited counterpart as well as glassy carbon electrode. The voltammetric and chronocoulometric results have indicated the high stability of the electrode with negligible adsorption. A positive shift in the peak potential with increasing pH indicated the attractive electrostatic interaction between the anodically oxidized diamond surface and the positively charged GSSG in acidic media that promoted its analytical performance. The results of the electrolysis experiments of disulfides and thiols showed that the oxidation reaction mechanism of glutathione (GSH) and GSSG involves oxygen transfer. Following separation by liquid chromatography (LC), the determination of both GSH and GSSG in rat whole blood was achieved at a constant potential (1.50 V vs Ag/AgCl), and the limits of detection for GSH and GSSG were found to be 1.4 nM (0.028 pmol) and 1.9 nM (0.037 pmol) with a linear calibration range up to 0.25 mM. These detection limits were much lower than those reported for the amperometry using Bi-PbO2 electrodes and LC-mass spectrometry, and the LC method using diamond electrodes were comparable with enzymatic assay in real sample analysis. The high response stability and reproducibility together with the possibility of regeneration of the electrode surface by on-line anodic treatment at 3 V for 30 min further support the applicability of anodically pretreated diamond for amperometric detection of disulfides.
Collapse
Affiliation(s)
- C Terashima
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | | | | | | | | |
Collapse
|
34
|
Honda K, Yoshimura M, Rao TN, Fujishima A. Electrogenerated Chemiluminescence of the Ruthenium Tris(2,2‘)bipyridyl/Amines System on a Boron-Doped Diamond Electrode. J Phys Chem B 2003. [DOI: 10.1021/jp022187h] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. Honda
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - M. Yoshimura
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tata N. Rao
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - A. Fujishima
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| |
Collapse
|
35
|
Abstract
Highly boron-doped diamond microfiber electrodes (BDDMF) were fabricated and characterized by the use of Scanning Electron Microscopy (SEM), Raman spectroscopy, and cyclic voltammetry. Amperometric detection of dopamine (DA), a neurotransmitter was achieved at pH 7.0, using BDDMF electrodes. The interferences from ascorbic acid (AA) and DOPAC were efficiently eliminated by using overoxidized polypyrrole-modified BDDMF electrodes, which also increased the sensitivity for the detection of dopamine. The limit of detection (S/N = 3) for dopamine was 0.1 nM, which is one order lower than that observed for carbon microfiber electrodes (CMFE), and the linear dynamic range was obtained from 0.5 nM to 100 microM (r2 = 0.997). The amperometric response for 0.5 nM dopamine has shown high stability with an RSD of 5.4% (n = 5). Highly reproducible results were obtained with an RSD of 6.2% for 10 measurements of 1 nM DA taken during 10 h and also remained the same, during measurements for 7 days, with no variation in efficiency for rejection of AA and DOPAC.
Collapse
Affiliation(s)
- H Olivia
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku. Tokyo 113-8656, Japan
| | | | | | | | | |
Collapse
|
36
|
Chailapakul O, Siangproh W, Sarada BV, Terashima C, Rao TN, Tryk DA, Fujishima A. The electrochemical oxidation of homocysteine at boron-doped diamond electrodes with application to HPLC amperometric detection. Analyst 2002; 127:1164-8. [PMID: 12375837 DOI: 10.1039/b205822g] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 11/21/2022]
Abstract
The electrochemical oxidation of homocysteine was studied at as-deposited and anodized (oxidized) boron-doped diamond (BDD) thin film electrodes with cyclic voltammetry, flow injection analysis and high-pressure liquid chromatography with amperometric detection. At anodized boron-doped diamond electrodes, highly reproducible, well-defined cyclic voltammograms for homocysteine oxidation were obtained in acidic media, while as-deposited diamond did not provide a detectable signal. In alkaline media, however, the oxidation response was obtained both at as-deposited and anodized diamond electrodes. The potential sweep rate dependence of homocysteine oxidation (peak currents for 1 mM homocysteine linearly proportional to v(1/2), within the range of 0.01 to 0.3 V s(-1)) indicates that the oxidation involves a diffusing species, with negligible adsorption on the BDD surface at this concentration. In the flow system, BDD exhibited a highly reproducible amperometric response, with a peak variation less than 2%. An extremely low detection limit (1 nM) was obtained at 1.6 V vs. Ag/AgCl. In addition, the determination of homocysteine in a standard mixture with aminothiols and disulfide compounds by means of isocratic reverse-phase HPLC with amperometric detection at diamond electrodes has been investigated. The results showed excellent separation, with a detection limit of 1 pmol and a linear range of three orders of magnitude.
Collapse
Affiliation(s)
- O Chailapakul
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | | | | | | | | | | | | |
Collapse
|
37
|
Amemiya T, Hashimoto K, Fujishima A. Dynamics of Faradaic processes in polypyrrole/polystyrenesulfonate composite films in the presence and absence of a redox species in aqueous solutions. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100118a041] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
38
|
Amemiya T, Hashimoto K, Fujishima A. Faradaic charge transfer with double-layer charging and/or adsorption-related charging at polymer-modified electrodes as observed by color impedance spectroscopy. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100140a033] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
39
|
Wang R, Iyoda T, Hashimoto K, Fujishima A. Selective In-Plane Photoelectrochemical Reaction of an Azobenzene Derivative in an Assembled Film. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100010a053] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
40
|
Sato O, Baba R, Hashimoto K, Fujishima A. Second harmonic generation coherent interferometry disclosing the orientation of the submerged hemicyanine layer in a Langmuir-Blodgett multilayer structure. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100177a009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
41
|
Ajito K, Nagahara LA, Tryk DA, Hashimoto K, Fujishima A. Study of the Photochromic Properties of Amorphous MoO3 Films Using Raman Microscopy. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100044a028] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
42
|
Amemiya T, Hashimoto K, Fujishima A. Frequency-resolved faradaic processes in polypyrrole films observed by electromodulation techniques: electrochemical impedance and color impedance spectroscopies. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100118a040] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
43
|
Abstract
Conductive boron-doped diamond thin-film electrodes were used for the electrochemical detection of selected N-methylcarbamate pesticides (carbaryl, carbofuran, methyl 2-benzimidazolecarbamate, bendiocarb) after liquid chromatographic separation. Two kinds of detection methods were adopted in this study. In the first method, a direct detection of underivatized pesticides was carried out at an operating potential of 1.45 V versus Ag/AgCl, which resulted in the detection limits of 5-20 ng/mL (or 5-20 ppb) with S/N = 2 due to the low background current and wide potential window of the diamond electrode. In the second method, the detection limits were improved by subjecting the pesticide samples to alkaline hydrolysis in a separate step prior to injection. The phenolic derivatives obtained by alkaline hydrolysis oxidize at a relatively lower potential (0.9 V vs Ag/AgCl), which increases the sensitivity drastically. The advantage of the diamond electrode for the detection of phenolic derivatives is that it offers excellent stability in comparison to other electrodes. This method gives the detection limits of 0.6-1 ng/mL (or 0.6-1 ppb), which are well below the maximum residue levels allowed for carbaryl, carbofuran, and bendiocarb. While the lowest detection limits (LOD) obtained by the direct detection of pesticides are comparable to the those reported by the well-established HPLC-fluorescence, the LODs of the alkaline hydrolysis method are found to be even lower than the reported limits. On-line reactivation of the diamond electrode surface was shown to be possible by an anodic treatment of the electrode at approximately 3 V for 30 min in case of electrode fouling, which may occur after a prolonged use. Such a treatment damages the glassy carbon (GC) and metal electrodes, while the diamond electrode remains stable. These results suggest that the diamond electrode is superior to the other previously used electrodes such as GC and Kelgraf type for highly sensitive and stable detection of carbamate pesticides.
Collapse
Affiliation(s)
- Tata N Rao
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Japan
| | | | | | | | | |
Collapse
|
44
|
Ivandini T, Sarada B, Terashima C, Rao T, Tryk D, Ishiguro H, Kubota Y, Fujishima A. Electrochemical detection of tricyclic antidepressant drugs by HPLC using highly boron-doped diamond electrodes. J Electroanal Chem (Lausanne) 2002. [DOI: 10.1016/s0022-0728(02)00666-6] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
45
|
Terashima C, Rao TN, Sarada BV, Tryk DA, Fujishima A. Electrochemical oxidation of chlorophenols at a boron-doped diamond electrode and their determination by high-performance liquid chromatography with amperometric detection. Anal Chem 2002; 74:895-902. [PMID: 11866070 DOI: 10.1021/ac010681w] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.1] [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: 11/29/2022]
Abstract
Anodically pretreated diamond electrodes have been used for the detection of chlorophenols (CPs) in environmental water samples after high-performance liquid chromatographic (HPLC) separation. The anodization of as-deposited boron-doped polycrystalline diamond thin-film electrodes has enabled the stable determination of phenols over a wide concentration range. Prior to the HPLC analysis, a comparative study with ordinary glassy carbon, as-deposited diamond, and anodized diamond was made to examine the oxidative behavior of phenols by cyclic voltammety and flow injection analysis with amperometric detection. At anodized diamond electrodes, reproducible, well-defined cyclic voltammograms were obtained even at high CP concentration (5 mM), due to a low proclivity for adsorption of the oxidation products on the surface. In addition, after prolonged use, the partially deactivated diamond could be reactivated on line by applying a highly anodic potential (2.64 Vvs SCE) for 4 min, which enabled the destruction of the electrodeposited polymer deposits. Hydroxyl radicals produced by the high applied potential, in which oxygen evolution occurs, are believed to be responsible for the oxidation of the passivating layer on the surface. When coupled with flow injection analysis (FIA), anodized diamond exhibited excellent stability, with a response variability of 2.3% (n = 100), for the oxidation of a high concentration (5 mM) of chlorophenol. In contrast, glassy carbon exhibited a response variability of 39.1%. After 100 injections, the relative peak intensity, for diamond decreased by 10%, while a drastic decrease of 70% was observed for glassy carbon. The detection limit obtained in the FIA mode for 2,4-dichlorophenol was found to be 20 nM (S/N = 3), with a linear dynamic range up to 100 microM. By coupling with the column-switching technique, which enabled on-line preconcentration (50 times), the detection limit was lowered to 0.4 nM (S/N = 3). By use of this technique, anodized diamond electrodes were demonstrated for the analysis of CPs in drainwater that was condensed from the flue gas of waste incinerators.
Collapse
Affiliation(s)
- C Terashima
- Department of Applied Chemistry, School of Engineering, University of Tokyo, Japan
| | | | | | | | | |
Collapse
|
46
|
|
47
|
Affiliation(s)
- J. F. Zhi
- Open Lab, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology, KSP Building East 412, 3-2-1 Sakado, Takatsu-ku, Kawasaki 213-0012, Japan, and Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8656, Japan
| | - H. B. Wang
- Open Lab, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology, KSP Building East 412, 3-2-1 Sakado, Takatsu-ku, Kawasaki 213-0012, Japan, and Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8656, Japan
| | - A. Fujishima
- Open Lab, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology, KSP Building East 412, 3-2-1 Sakado, Takatsu-ku, Kawasaki 213-0012, Japan, and Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8656, Japan
| |
Collapse
|
48
|
Shimizu K, Einaga Y, Ohnishi K, Fujishima A, Habazaki H, Skeldon P, Thompson GE. Radio frequency GDOES depth profiling analysis of a B-doped diamond film deposited onto Si by microwave plasma CVD. SURF INTERFACE ANAL 2002. [DOI: 10.1002/sia.1158] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
49
|
Yokoyama K, Kimura Y, Matsumoto K, Fujishima A, Miyazaki T. Preventive effect of tooth fracture by pulsed Nd:YAG laser irradiation with diamine silver fluoride solution. J Clin Laser Med Surg 2001; 19:315-8. [PMID: 11776449 DOI: 10.1089/104454701753342767] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The purpose of the present study was to evaluate the preventive effect of pulsed Nd:YAG laser irradiation with 38% diamine silver fluoride [Ag(NH3)2F] solution for the fracture of endodontically treated teeth in vitro. BACKGROUND DATA There have been no reports on the preventive effect of tooth fracture using Nd:YAG laser with Ag(NH3)2F solution. MATERIALS AND METHODS Twenty-eight human extracted teeth were used in this study. The teeth were randomly classified into four groups: control group, where tooth surfaces were not submitted to any treatment; group 1, where tooth surfaces were coated with 38% Ag(NH3)2F solution; group 2, where tooth surfaces were coated with Ag(NH3)2F solution and irradiated by pulsed Nd:YAG laser for 2 sec; and group 3, where tooth surfaces were coated with Ag(NH3)2F solution and irradiated by pulsed Nd:YAG laser for 10 sec. After preparation, shear tests were performed and the maximum load for the fracture was measured. Results were analyzed using the Scheffe test, and difference at p < 0.05 was considered significant. RESULTS The failure load for group 2 (mean, 182.5 kg) had the highest mean value and differed significantly from those for the control group (mean, 146.3 kg) and group 1 (mean, 147.1 kg; p < 0.05). The failure loads for groups 1 and 3 (mean, 150.0 kg) did not differ significantly from that for the control group (p > 0.05). CONCLUSION The results show that the application of 38% Ag(NH3)2F solution followed by pulsed Nd:YAG laser irradiation for 2 sec is useful for prevention of tooth fracture at endodontically treated teeth.
Collapse
Affiliation(s)
- K Yokoyama
- Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan.
| | | | | | | | | |
Collapse
|
50
|
Hayami S, Gu Z, Yoshiki H, Fujishima A, Sato O. Iron(III) spin-crossover compounds with a wide apparent thermal hysteresis around room temperature. J Am Chem Soc 2001; 123:11644-50. [PMID: 11716720 DOI: 10.1021/ja0017920] [Citation(s) in RCA: 257] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The magnetic properties of the spin-crossover compounds, [Fe(qsal)2]NCSe-MeOH (1) and [Fe(qsal)2]NCSe-CH2Cl2 (2), have been measured. We have discovered that both compounds 1 and 2 exhibit a wide thermal hysteresis loop of 140 K (T(1/2) upward arrow = 352 K and T(1/2) downward arrow = 212 K) and 180 K (T(1/2) upward arrow = 392 K and T(1/2) downward arrow = 212 K), respectively, in the first cycle. Thermogravimetric analysis shows that solvent molecules escape from compounds 1 and 2 around 340 and 395 K, respectively. This means that the hysteresis loops observed for the first cycle are only apparent ones. Following the first loop, they show a two-step spin-crossover in warming mode. The so-called "step 1" and "step 2" are centered around T(1/2(S1)) upward arrow = 215 K and T(1/2(S2)) upward arrow = 282 K, respectively. On the other hand, a one-step spin-crossover occurs at T(1/2) downward arrow = 212 K in cooling mode. The hysteresis widths can be estimated to be 3 K (step 1) and 70 K (step 2), assuming that the widths in steps 1 and 2 are defined as the differences between T(1/2(S1)) upward arrow and T(1/2) downward arrow, and T(1/2(S2)) upward arrow and T(1/2) downward arrow, respectively. The hysteresis width of 70 K in step 2 is one of the widest values reported so far for spin-crossover complexes. It is thought that the cooperativity operating in the complexes arises mainly from the intermolecular pi interactions between quinoline and phenyl rings. Using a previously reported model, we are able to simulate the hysteresis loop with a two-step spin-crossover in warming mode and a one-step transition in cooling mode.
Collapse
Affiliation(s)
- S Hayami
- Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology, East 412, 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa 213-0012, Japan
| | | | | | | | | |
Collapse
|