Journal of Pesticide Science
Online ISSN : 1349-0923
Print ISSN : 1348-589X
ISSN-L : 0385-1559
Volume 35, Issue 3
Displaying 1-30 of 30 articles from this issue
Special Topic
Reviews
  • Tetsuo Satoh, Masakiyo Hosokawa
    Article type: Review
    2010 Volume 35 Issue 3 Pages 218-228
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 15, 2010
    JOURNAL FREE ACCESS
    This review covers current developments in molecular-based studies of the structure and function of carboxylesterases. To allay the confusion of the classic classification of carboxylesterase isozymes, we propose a novel nomenclature and classification of mammalian carboxylesterases on the basis of molecular properties. Mechanisms of the regulation of the gene expression of carboxylesterases by xenobiotics, and the involvement of carboxylesterase in drug metabolism are also described. The novel biomarker for organophosphate pesticide exposure developed here is much more useful and reliable than cholinesterase inhibition.
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  • Teruko Imai, Masakiyo Hosokawa
    Article type: Review
    2010 Volume 35 Issue 3 Pages 229-239
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 15, 2010
    JOURNAL FREE ACCESS
    A prodrug is a pharmacologically inactive derivative of an active parent drug, and is bioconverted to the active drug in vivo. Through chemical modification of a drug to a prodrug, we are able to deliver drugs to the target site, to optimize therapy and minimize toxicity. A major pathway for the bioconversion of prodrugs to the active parent drugs is via carboxylesterase (CES) activity. Among human CES isozymes, hCE1 and hCE2 predominantly participate in the hydrolysis of prodrugs in the liver and small intestine, respectively, although the substrate specificity is quite different between two isozymes; therefore, we can rationally design prodrugs based on the enzyme characteristics. However, since the expression levels of CES vary among individuals, there is a range of pharmacological responses following prodrug administration. Species differences are caused by tissue-dependent hydrolase activity mediated by CES, which makes it difficult to predict effectiveness in humans from a preclinical study using animals. Accordingly, understanding the regulation of CES expression and species difference of CES catalytic properties will be helpful in the design of prodrugs with increased specificity and enhanced physicochemical and biological properties.
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  • Shana V. Stoddard, Xiaozhen Yu, Philip M. Potter, Randy M. Wadkins
    Article type: Review
    2010 Volume 35 Issue 3 Pages 240-249
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 15, 2010
    JOURNAL FREE ACCESS
    Carboxylesterases (CEs) are important enzymes that catalyze biological detoxification, hydrolysis of certain pesticides, and metabolism of many esterified drugs. The development of inhibitors for CE has many potential uses, including increasing drug lifetime and altering biodistrubution; reducing or abrogating toxicity of metabolized drugs; and reducing pest resistance to insecticides. In this review, we discuss the major classes of known mammalian CE inhibitors and describe our computational efforts to design new scaffolds for development of novel, selective inhibitors. We discuss several strategies for in silico inhibitor development, including structure docking, database searching, multidimensional quantitative structure–activity analysis (QSAR), and a newly-used approach that uses QSAR combined with de novo drug design. While our research is focused on design of specific inhibitors for human intestinal carboxylesterase (hiCE), the methods described are generally applicable to inhibitors of other enzymes, including CE from other tissues and organisms.
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  • Andrew C. Hemmert, Matthew R. Redinbo
    Article type: Review
    2010 Volume 35 Issue 3 Pages 250-256
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 26, 2010
    JOURNAL FREE ACCESS
    Human carboxylesterase 1 (hCE1) is the primary carboxylesterase expressed in the liver. This critical member of the phase I drug metabolism pathway detoxifies a wide-range of endobiotics, xenobiotics, and agrochemicals. To date, more than a dozen X-ray crystal structures have been elucidated of hCE1 in complex with a broad spectrum of ligands, including organophosphates. These structures provide valuable insights into agrochemical binding and metabolism by hCE1. For example, variable binding pockets that frame the enzyme's catalytic triad and a long, flexible loop capping this region appear to regulate substrate affinity. Stereoisomers of organophosphates illustrate the substrate selectivity of these two pockets. In contrast, pyrethroid isomers likely impact the positioning of the oxyanion hole required to stabilize the negatively charged transition-state oxygen. Finally, it appears that rates of spontaneous hCE1 reactivation in the presence of organophosphates are significantly affected by alkoxy placement within the active site.
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  • Matthew K. Ross, Timothy M. Streit, Katye L. Herring, Shuqi Xie
    Article type: Review
    2010 Volume 35 Issue 3 Pages 257-264
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 26, 2010
    JOURNAL FREE ACCESS
    Carboxylesterases (CES, EC 3.1.1.1) are members of a superfamily of serine hydrolases that hydrolyze ester, amide, and carbamate bonds. Several different CES genes exist in mammalian species with evidence of multiple gene duplication events occurring throughout evolutionary history. There are five CES genes reported in the Human Genome Organization database, although CES1 and CES2 are the two best characterized human genes. An emerging picture of the CES family suggests that these enzymes have dual roles in the metabolism of xenobiotic and endobiotic compounds. Pesticides, such as the pyrethroids, are important xenobiotic substrates that are metabolized by CES, whereas cholesteryl esters, triacylglycerols, and 2-arachidonoylglycerol are examples of endobiotics known to be substrates for CES. Functional studies using selective chemical inhibitors, siRNA, and gene knockout models are providing valuable insights into the physiological functions of CES, and suggest that CES may be a novel target for the treatment of diseases such as diabetes and atherosclerosis. This review will examine the known physiological functions of CES, the interactions between xenobiotics (primarily pesticides) and lipids that occur with CES enzymes, and where possible the implications that these findings may have in terms of health and disease.
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  • Shizuo G. Kamita, Bruce D. Hammock
    Article type: Review
    2010 Volume 35 Issue 3 Pages 265-274
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: June 18, 2010
    JOURNAL FREE ACCESS
    Normal insect development requires a precisely timed, precipitous drop in hemolymph juvenile hormone (JH) titer. This drop occurs through a coordinated halt in JH biosynthesis and increase in JH metabolism. In many species, JH esterase (JHE) is critical for metabolism of the resonance-stabilized methyl ester of JH. JHE metabolizes JH with a high kcat/KM ratio that results primarily from an exceptionally low KM. Here we review the biochemistry and structure of authentic and recombinant JHEs from six insect orders, and present updated diagnostic criteria that help to distinguish JHEs from other carboxylesterases. The use of a JHE-encoding gene to improve the insecticidal efficacy of biopesticides is also discussed.
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  • Juan C. Sanchez-Hernandez
    Article type: Review
    2010 Volume 35 Issue 3 Pages 290-301
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: August 07, 2010
    JOURNAL FREE ACCESS
    Chemical control of pests is still necessary in agriculture, despite the growing efforts to introduce biocontrol-based strategies. Many studies have evidenced the harm of pesticide side-effects on natural populations of pest enemies and other non-target organisms. Moreover, pesticide-contaminated soils can act as a secondary pollution source causing contamination in environmental compartments of critical concern to public health (water resource). These environmental risks need to be assessed and monitored for decision-making related to the post-authorization management of pesticides. Under these considerations, earthworm esterases can be a suitable tool for these regulatory and environmental purposes. Herein, it is suggested the use of earthworm esterases as biomarkers to be included in a field toxicity test. Furthermore, the potential role of gut carboxylesterases (CEs) in the modulation of pesticide toxicity is discussed in view of their contribution to the natural tolerance of earthworms to pesticides, and consequently the appropriate selection of earthworm species for regulatory toxicity testing. Finally, it is postulated that CE secretion into the earthworm gut could be an environmental friendly methodology in the enzymatic bioremediation of pesticide-contaminated soils.
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  • Claire A. Farnsworth, Mark G. Teese, Guorui Yuan, Yongqiang Li, Colin ...
    Article type: Review
    2010 Volume 35 Issue 3 Pages 275-289
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 15, 2010
    JOURNAL FREE ACCESS
    Elevated esterase activities and increased band intensities of multiple esterase isozymes after electrophoresis are commonly associated with resistance to organophosphate, pyrethroid and carbamate insecticides in various heliothine and spodopteran pests. One possible explanation for this involves a ‘master regulator’ mutation in a more general chemical stress response. An association between elevated esterase activities and isozyme intensities has also been reported for resistance to the Cry1Ac toxin of Helicoverpa armigera. The basis for this is unclear albeit some involvement of esterases could be mediated by the toxin's affinity for N-acetyl galactosamine glycans on certain gut-expressed esterases in this species.
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Original Article
  • Bryn M. Phillips, Brian S. Anderson, Jennifer P. Voorhees, John W. Hun ...
    Article type: Original Article
    2010 Volume 35 Issue 3 Pages 302-309
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 25, 2010
    JOURNAL FREE ACCESS
    As part of a statewide assessment of pyrethroid pesticides and sediment toxicity in urban creeks, sites throughout California were screened, and thirty were chosen to evaluate the potential of pyrethroids to contribute to biological impacts. Sediment samples from four sites containing varied concentrations of pyrethroids were investigated using toxicity identification evaluations (TIEs) to determine causes of toxicity. Treatments were conducted on both whole sediment and interstitial water to determine the role of pyrethroids in the observed toxicity to the amphipod Hyalella azteca, and to evaluate TIE method performance. Whole sediment treatments included the addition of binding resins for organics and metals, and specific treatments designed to alter pyrethroid toxicity, including the addition of carboxylesterase enzyme, the addition of piperonyl butoxide (a pyrethroid synergist), and the testing of sediments at two temperatures. Interstitial water TIEs included solid-phase extraction (SPE) columns to reduce and return toxicity caused by organics and metals, as well as the treatments specific to pyrethroids. Resin and SPE column treatments characterized the causes of toxicity as organic compounds. Results of pyrethroid-specific treatments in whole sediment were variable, but similar treatments in interstitial water demonstrated pyrethroids were contributing to toxicity. Measured pyrethroid concentrations in whole sediment and interstitial water SPE extracts were high enough to have contributed to toxicity. Using both whole sediment and interstitial water TIEs and chemical analysis provided multiple lines of evidence that pyrethroids contributed to toxicity.
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Commentaries
  • Takuya Tsubota, Takahiro Shiotsuki
    Article type: Commentary
    2010 Volume 35 Issue 3 Pages 310-314
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 26, 2010
    JOURNAL FREE ACCESS
    Supplementary material
    The complete genome sequence data of insects in five orders are now available. In this commentary we provide recent genomic and phylogenetic analyses of insect carboxyl/cholinesterases (CCEs). Multiple CCEs are found in each insect species, and at present the silkworm Bombyx mori has the largest number and diversity of CCEs. Phylogenetic analyses of the 425 CCE sequences identified species or order specific clustering, but for some CCEs 1:1 orthologous relationships were apparent. Phylogenetic analyses will be useful for further functional analysis of CCEs and the development of species-specific insecticides and/or synergists.
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  • Thierry Hotelier, Vincent Nègre, Pascale Marchot, Arnaud Chaton ...
    Article type: Commentary
    2010 Volume 35 Issue 3 Pages 315-320
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: August 07, 2010
    JOURNAL FREE ACCESS
    Resistance of arthropods to organophosphates and carbamates used as insecticides is mainly due to mutations in genes encoding carboxylesterase or acetylcholinesterase members of the alpha/beta-hydrolase fold superfamily of proteins. Mutations that have been described at the molecular level concern 24 species, 31 genes and 32 identical positions in the aligned aminoacid sequences. Seven of these positions are found in more than four species and can be considered as hot spots for mutations. Mutations in one single gene also result in cross resistance to pyrethroids. These figures along with all pieces of information related to these mutations can be recovered from the ESTHER database, dedicated to the alpha/beta-hydrolase fold superfamily (http://bioweb.ensam.inra.fr/esther), through built-in or custom made queries. A sequence alignment of enzymes involved in resistance with highlighted mutated amino acid residues is provided. Selecting one amino acid residue leads to all information about mutations analyzed at this position. Links to the related literature are also available.
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Short Communication
  • Yumi Ikeda, Ryuta Ohno, Yukiharu Sato
    Article type: Short Communication
    2010 Volume 35 Issue 3 Pages 321-325
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 22, 2010
    JOURNAL FREE ACCESS
    4-Hydroxyphenylpyruvate dioxygenase (4-HPPD), one of the target enzymes for bleaching herbicides, was known to be deactivated by making a Fe2+-chelate combination with inhibitors at its active site. Complexation abilities of 1-phenylbutane-1,3-dione derivative, 2-cyano-4-phenylbutane-1,3-dione derivative, benzoylcyclohexane-1,3-diones and benzoylpyrazole derivatives with Fe2+ was demonstrated by spectrophotometric analysis under different concentrations of iron (II) sulfate aqueous solution. The active forms of pyrazolate in the presence of Fe2+ showed large changes in UV absorbance, whereas no apparent changes were observed with non 4-HPPD inhibiting compounds. UV analysis using iron (II) sulfate aqueous solution was a convenient method before 4-HPPD-inhibiting assay and pot test with intact plants in the screening of novel candidates for 4-HPPD inhibitors.
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Original Articles
  • Ryota Kataoka, Kazuhiro Takagi, Futa Sakakibara
    Article type: Original Article
    2010 Volume 35 Issue 3 Pages 326-332
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 15, 2010
    JOURNAL FREE ACCESS
    Two new aerobic endosulfan-degrading fungal strains, Mortierella sp. strains W8 and Cm1-45, were isolated from soil contaminated with organochlorine pesticides. This is the first report on the biodegradation of endosulfan by Zygomycota. The strains isolated in this work degraded more than 70% and 50% of α and β-endosulfan, respectively, over 28 days at 25°C, whereas 8.2 μM of each a and β-endosulfan was added as the initial concentration in liquid cultures. Only a small amount of endosulfan sulfate, a persistent metabolite, was detected in both cultures, while these strains could not degrade endosulfan sulfate when incubated with endosulfan sulfate as the initial substrate. Both strains generate endosulfan diol as a first step in the degradation of endosulfan and then undergo further conversion to endosulfan lactone. The formation of these intermediates was confirmed by GC-MS. Mortierella spp. might be present as hyphae in contaminated soil because they were isolated using the soil washing method; therefore, these Mortierella spp. strains have potential for the bioremediation of contaminated sites with endosulfan.
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  • Yasser El-Nahhal, Jamal Safi
    Article type: Original Article
    2010 Volume 35 Issue 3 Pages 333-338
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: June 25, 2010
    JOURNAL FREE ACCESS
    This study investigates the adsorption behavior of bromoxynil under various pH and temperature conditions. Organo-bentonite complexes were prepared and used as adsorbents for bromoxynil. The concentrations of bromoxynil in equilibrium solution were determined by HPLC. Results showed that bromoxynil was best adsorbed by bentonite surfaces modified with NCP or HDTBP at various loadings, and adsorption was further enhanced by lowering the pH and/or optimizing the temperature of the adsorption reaction. Release of bromoxynil from NCP-, or HDTBP-bentonite- bromoxynil was slower than from raw bentonite-bromoxynil. Organo-bentonite complexes may be suitable materials for designing controlled release formulations of herbicides.
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  • Ling Zhu, Zhenghui Wang, Shuting Zhang, Xiaoyan Long
    Article type: Original Article
    2010 Volume 35 Issue 3 Pages 339-343
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: July 02, 2010
    JOURNAL FREE ACCESS
    The objective of this work was to explore the possible efficient application of pesticides in an environmentally friendly way. The present paper reports the preparation, characterization and bioassay of chlorpyrifos-containing microcapsules. With trimer of isophorone diisocyanate and triethylenetetramine as wall-forming materials, sodium dodecylsulfate and xanthan gum as stabilizers, and an emulsifying speed of 3000 rpm for 12 min, chlorpyrifos-containing microcapsules, with a diameter ranging 2–7 μm and an initial encapsulation rate of 94.7%, were prepared by fast interfacial polymerization at room temperature. Formulations based on the prepared microcapsules are stable in neutral medium and release chlorpyrifos in both acidic and alkaline media. The results of bioassay against 3rd-instar Spodoptera litura larvae showed that microcapsule formulations had more sustainable efficacy than that of conventional emulsion formulations. The idea and approach presented in this work have potential application in the pesticide industry.
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Note
  • Hyun Il Kim, Xiaonan Xie, Han Sung Kim, Jae Chul Chun, Kaori Yoneyama, ...
    Article type: Note
    2010 Volume 35 Issue 3 Pages 344-347
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: August 07, 2010
    JOURNAL FREE ACCESS
    Eleven naturally occurring strigolactones (SLs) were examined for their germination-stimulating activity on the seeds of a root parasitic plant Orobanche minor Sm. Based on their activity, SLs are classified into 3 groups (A–C). Group A, the most active germination stimulant, consists of 3 monohydroxy-SLs, orobanchol, 2′-epiorobanchol, and sorgomol, inducing >80% germination of O. minor seeds at 10 pM. Group B includes 5 SLs, which were ca. 10-fold less active than those in group A. The 3 least active SLs in group C were either more lipophilic or probably less stable than SLs in groups A and B. These results indicate that the germination-stimulating activity of SLs depends on the lipophilicity of the SL molecules and their stability also influences activity. Other structural features for germination-stimulating activity are also discussed.
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Society Awards 2010
  • Makoto Fujimura
    Article type: Society Awards 2010
    2010 Volume 35 Issue 3 Pages 351-353
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: August 07, 2010
    JOURNAL FREE ACCESS
    The mechanism of action of dicarboximides and phenylpyrroles has been studied in Neurospora crassa. Both fungicides were found to interfere with the signal transduction pathway composed of the following components: osmotic-sensitive (OS)-1 histidine kinase, histidine phosphotransfer protein (HPT)-1, response regulator protein (RRG)-1, OS-4 mitogen-activated protein kinase (MAPK) kinase kinase, OS-5 MAPK kinase, and OS-2 MAPK. All the components, except HPT-1, were essential for the sensitivity to both fungicides and adaptation to osmotic stress. In contrast, the hpt-1 deletion mutation was lethal unless OS-2 was inactivated. Fludioxonil, osmotic stress, and heat shock induced OS-2 activation by phosphorylation. OS-2 regulated various genes, such as gcy-1, which encodes glycerol dehydrogenase; cat-1, which encodes conidial catalase; and the clock-controlled gene (ccg)-1. This implies that the signaling pathway plays an important role not only in the stress response but also in asexual differentiation and circadian output. We found 3 types of dicarboximide-resistant mutations in the BcOS1 gene of Botrytis cinerea, of which the I365S mutation was dominant in the fields. A hybridization probe assay was developed to detect these mutations in a single polymerase chain reaction that may be suitable for monitoring the development of resistance to various fungicides.
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  • Koichi Yoneyama
    Article type: Society Awards 2010
    2010 Volume 35 Issue 3 Pages 348-350
    Published: August 25, 2010
    Released on J-STAGE: August 31, 2010
    Advance online publication: August 07, 2010
    JOURNAL FREE ACCESS
    Among parasitic angiosperms, witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.) are the two most devastating root parasitic plants, causing enormous crop losses around the world. These root parasites have evolved special strategies to ensure their survival; the seeds germinate only when they are within the host rhizosphere so that after germination the seedlings can reach and parasitize the host roots. To locate host roots, root parasites exploit strigolactones (SLs), host-derived chemical signals that are released by host plants for symbiotic arbuscular mycorrhizal (AM) fungi. In addition to these functions as rhizosphere signaling molecules, SLs act as a class of plant hormones regulating shoot branching. Using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), SLs in root exudates from various plants have been characterized. During studies, in addition to the known SLs, more than 10 novel SLs have been isolated and their structures determined. Plants produce and exude mixtures of SLs, and nutrient availability affects SL production and exudation. These results suggest that quantitative and qualitative differences in SL production and/or exudation are important in host recognition of root parasitic plants.
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Errata
PART II (IN JAPANESE)
The Society Award Lectures
  • Koichi Yoneyama
    Article type: The Society Award Lectures
    2010 Volume 35 Issue 3 Pages 355-362
    Published: August 25, 2010
    Released on J-STAGE: December 16, 2013
    JOURNAL FREE ACCESS
    Among parasitic angiosperms, witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.) are the two most devastating root parasitic plants, causing enormous crop losses around the world. These root parasites have evolved special strategies to ensure their survival; the seeds germinate only when they are within the host rhizosphere so that after germination the seedlings can reach and parasitize the host roots. To locate host roots, root parasites exploit strigolactones (SLs), host-derived chemical signals that are released by host plants for symbiotic arbuscular mycorrhizal (AM) fungi. In addition to these functions as rhizosphere signaling molecules, SLs act as a class of plant hormones regulating shoot branching. Using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), SLs in root exudates from various plants have been characterized. During studies, in addition to the known SLs, more than 10 novel SLs have been isolated and their structures determined. Plants produce and exude mixtures of SLs, and nutrient availability affects SL production and exudation. These results suggest that quantitative and qualitative differences in SL production and/or exudation are important in host recognition of root parasitic plants.
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  • Makoto Fujimura
    Article type: The Society Award Lectures
    2010 Volume 35 Issue 3 Pages 363-369
    Published: August 25, 2010
    Released on J-STAGE: December 16, 2013
    JOURNAL FREE ACCESS
    Download PDF (548K)
  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    Article type: The Society Award Lectures
    2010 Volume 35 Issue 3 Pages 370-372
    Published: August 25, 2010
    Released on J-STAGE: December 16, 2013
    JOURNAL FREE ACCESS
    Download PDF (190K)
Abstracts of Articles in Part I
Commentaries
Seminar: Experimental Techniques
Symposia
Book Review
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