著者

Kazuki Okamoto Tomohito Wakasa Jun Taniguchi Shin-ichi Satake

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.35, no.2, pp.125-130, 2022-12-16 (Released:2023-03-14)

参考文献数

20

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Performing the minimum number of ultraviolet nanoimprint lithography imprints is important for ensuring high throughput and low costs. The stamp lifetime can be estimated quickly from little information during imprint processing. We proposed two methods to predict the stamp lifetime from durability test data with a line-patterned mold. We characterized the contact angle, concentration of release resin, and the number of imprints from the data. Both of the proposed methods used machine learning. One method was binary classification, and the other was regression analysis. Under the binary classification method, the recall was 50% and the prediction showed that the recall becomes 0% when Gaussian random noise is added. Under the regression analysis, the prediction did not drastically change, with an approximately 100-fold increase in the mean absolute error. The results show that regression analysis is useful for predicting the lifetime of a line-patterned mold.

著者

Jun Miyata Hirotomo Yamanashi Shin-Ya Kawashiri Sakiko Soutome Kazuhiko Arima Mami Tamai Fumiaki Nonaka Yukiko Honda Masayasu Kitamura Koji Yoshida Yuji Shimizu Naomi Hayashida Shigeru Kawakami Noboru Takamura Takashi Sawase Atsutoshi Yoshimura Yasuhiro Nagata Mayumi Ohnishi Kiyoshi Aoyagi Atsushi Kawakami Toshiyuki Saito Takahiro Maeda

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

pp.JE20230079, (Released:2023-07-29)

参考文献数

42

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In an aging society, it is important to visualize the conditions of people living with diseases or disabilities, such as frailty and sarcopenia, and determine the environmental and genetic factors underlying such conditions. Atherosclerosis and arterial stiffness are key conditions between these factors and noncommunicable diseases. In 2014, we launched a population-based prospective open-cohort study, the Nagasaki Islands Study (NaIS), which was conducted in Goto City, located in the remote islands of Nagasaki Prefecture, Japan, mostly involving middle-aged and older residents. We conducted our own health checkups along with the annual standardized checkups organized by the municipality; recruited study participants; and started to follow-up with them for vital status (death), migration, and occurrence of diseases such as myocardial infarction, stroke, fracture, and human T-cell leukemia virus type 1 (HTLV-1) -associated uveitis. Our checkups were conducted as baseline surveys in different areas of Goto City during the fiscal years 2014–2016, secondary surveys during 2017–2019, and tertiary surveys since 2021, consisting of medical interviews, physical examinations, blood and urine tests, body composition measurements, osteoporosis screening, arterial stiffness measurements, carotid ultrasonography, and dental examination. A total of 4,957 residents participated in either the baseline or secondary surveys and were followed-up; and 3,594 and 3,364 residents (aged 27–96 and 28–98 years) participated in the baseline and secondary surveys, respectively. In conclusion, the NaIS has been undertaken to reveal the influence of aging and risk factors of noncommunicable diseases and disabilities, with an aim to contribute towards better healthcare in the future.

著者

Namiko Sakurai Koyuru Iwanami Shingo Shimizu Yasushi Uji Shin-ichi Suzuki Takeshi Maesaka Ken-ichi Shimose Paul R. Krehbiel William Rison Daniel Rodeheffer

出版者

Fuji Technology Press Ltd.

雑誌

Journal of Disaster Research (ISSN:18812473)

巻号頁・発行日

vol.16, no.4, pp.778-785, 2021-06-01 (Released:2021-06-01)

参考文献数

26

被引用文献数

2

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The National Research Institute for Earth Science and Disaster Resilience deployed a lightning mapping array (LMA) in the Tokyo metropolitan area in March 2017. Called the “Tokyo LMA,” it obtains detailed three-dimensional observations of the total lightning activity (cloud-to-ground and intracloud flashes) in storms. The network initially consisted of 8 receiving stations, expanded to 12 stations in March 2018. Real-time total lightning images were first opened on the webpage in Japan. Real-time observations from the Tokyo LMA will be used in nowcasting lightning hazards and mitigating lightning disasters. Archived data will be used to develop lightning prediction techniques and a lightning climatology for the Tokyo metropolitan area.

著者

Shin-Ichi SEKI

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.22, no.2, pp.137-150, 2023 (Released:2023-08-01)

参考文献数

66

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The Ryukyu Robin species complex, including the Ryukyu Robin Larvivora komadori and the Okinawa Robin L. namiyei, is endemic to the islands of the Ryukyu Archipelago. Population genetic structure and gene flow within this complex were investigated using 14 nuclear microsatellite markers. Distinct genetic differentiation was detected between the Ryukyu and Okinawa robins, and the Ryukyu Robin was further differentiated into four regional groups belonging to the Danjo Islands, Tokara Islands, Oh-shima with some adjacent islands, and Tokuno-shima. Contemporary gene flow among these regional groups was restricted overall, but outflow from the Tokara Islands group to the other three groups was exceptionally high. This asymmetric pattern may have been affected by differences in the isolation distance, migratory habits, and population size. The Ryukyu Robin species complex was long considered a single polytypic species; however, it has recently been classified as two independent species, mainly owing to the deep mitochondrial DNA divergence between them and a phenotypical re-examination. The genetic structure inferred from the nuclear loci strongly supports their genetic independence. The Okinawa Robin provides the first case among birds for which the splitting of sister species both endemic to the Ryukyu Archipelago is supported by all of the morphological, behavioral, ecological, and genetic evidence. Such recognition appears preferable in avian conservation and biogeography studies. Currently, the Ryukyu Archipelago includes an Endemic Bird Area and two Natural World Heritage sites, making the reliable delimitation of endemic species all the more important. Comprehensive genetic investigation, together with phenotypical re-examination is necessary, even for closely resembling but allopatric sister forms in this region.

著者

.*Yurie Shin 川島 朋也 篠原 一光

雑誌

日本心理学会第87回大会

巻号頁・発行日

2023-08-03

著者

Naoyuki NISHIO Shin-Ichiro NISHIDA Shintaro NAKATANI

出版者

THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES

雑誌

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN (ISSN:18840485)

巻号頁・発行日

vol.19, no.4, pp.469-476, 2021 (Released:2021-07-04)

参考文献数

16

被引用文献数

1

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The rover for future Mars exploration will be expected to have higher rough terrain traveling performance compared with conventional rovers. In this paper, we propose a rover with a weight of about 30 kg that can be transported to Mars by a Japanese rocket. The purpose of this study is to propose and develop a hinge-type movable center-of-gravity mechanism wherein the bending of the rover's body with a motor shows high rough terrain-driving performance with minimum degrees of freedom. The proposed mechanism's performance is evaluated by conducting travel experiments on a assumed terrain, that is, a hard rock with a grade inclination of 45 deg and a height of 0.15 m above the sand. The effectiveness of the proposed mechanism in getting over a step was confirmed by conducting experiments using a prototype model.

著者

Da Young Shin Hiroaki Takagi Michio Hiroshima Satomi Matsuoka Masahiro Ueda

出版者

Japan Society for Cell Biology

雑誌

Cell Structure and Function (ISSN:03867196)

巻号頁・発行日

vol.48, no.2, pp.145-160, 2023 (Released:2023-08-31)

参考文献数

58

被引用文献数

2

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In eukaryotic motile cells, the active Ras (Ras-GTP)-enriched domain is generated in an asymmetric manner on the cell membrane through the excitable dynamics of an intracellular signaling network. This asymmetric Ras signaling regulates pseudopod formation for both spontaneous random migration and chemoattractant-induced directional migration. While membrane lipids, such as sphingomyelin and phosphatidylserine, contribute to Ras signaling in various cell types, whether they are involved in the Ras excitability for cell motility is unknown. Here we report that functional Ras excitability requires the normal metabolism of sphingomyelin for efficient cell motility and chemotaxis. The pharmacological blockade of sphingomyelin metabolism by an acid-sphingomyelinase inhibitor, fendiline, and other inhibitors suppressed the excitable generation of the stable Ras-GTP-enriched domain. The suppressed excitability failed to invoke enough basal motility to achieve directed migration under shallow chemoattractant gradients. The fendiline-induced defects in Ras excitability, motility and stimulation-elicited directionality were due to an accumulation of sphingomyelin on the membrane, which could be recovered by exogenous sphingomyelinase or phosphatidylserine without changing the expression of Ras. These results indicate a novel regulatory mechanism of the excitable system by membrane lipids, in which sphingomyelin metabolism provides a membrane environment to ensure Ras excitation for efficient cellular motility and chemotaxis.Key words: cell polarity, cell migration, Ras, excitability, sphingomyelin

著者

Yuma Yokota Ayumi Fukazawa Yudai Nonaka Takuya Karasawa Michiyo Kimura Shin Terada

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.72, no.9, pp.849-858, 2023 (Released:2023-08-31)

参考文献数

35

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Dietary intake of medium-chain triacylglycerols (MCTs) is known to alleviate obesity. MCTs have also been suggested to beneficially influence protein metabolism. This study evaluated the effects of dietary intake of MCTs on energy restriction-induced weight control and loss of skeletal muscle. Rats were divided into the following groups: 1) AL-LCT group that received the AIN-93G-based control diet containing long-chain triacylglycerols (LCTs) ad libitum, 2) ER-LCT group fed the control diet with 30% energy restriction, and 3) ER-MCT group fed a diet containing MCTs with 30% energy restriction. After the 4-wk dietary treatment, both energy-restricted groups had significantly lower body weight than the AL-LCT group and rats in the ER-MCT group were significantly lighter than those in the ER-LCT group. In contrast, the extent of energy restriction-induced loss of skeletal muscle was not significantly different between the two energy-restricted groups, resulting in an increase in muscle mass relative to body weight in the ER-MCT group. Despite maintaining the lower body weight, dietary intake of MCTs did not further influence signaling pathways involved in protein synthesis or breakdown. These results suggest that intake of MCTs could be a valuable dietary intervention to maintain a lower body weight and increase relative muscle mass without negative effects on skeletal muscle protein metabolism.

著者

Hiroaki MURAYAMA Kazuya KANEMARU Hideyuki YOSHIOKA Akira FUKAMACHI Tsuneo SHIMIZU Tomohiro OMATA Isao FUKASAWA Mitsuyasu NAGASAKA Shin NAKANO Yasuhiro ASARI Hiroyuki KINOUCHI

出版者

The Japan Neurosurgical Society

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

pp.2023-0004, (Released:2023-08-23)

参考文献数

43

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Aneurysmal subarachnoid hemorrhage (SAH) treatment has progressed, and patients are rapidly aging in Japan. Consequently, dynamic changes must have emerged in the clinical practice of SAH. This study aimed to elucidate chronological changes of aneurysmal SAH and the prognostic factors in the previous quarter century in Japan. We conducted a retrospective survey regarding aneurysmal SAH in eight institutions in Japan. The study included 848, 863, and 781 patients in the first (1989-1993), second (1999-2003), and third (2009-2013) periods, respectively. The chronological changes of factors that influenced the poor outcomes and differences between the nonelderly (<75 years) and elderly patients were investigated. Mean age was significantly higher in patients in the third period (61.4 years) than in those in the other two periods (first, 57.8 years; second, 59.5 years). During these periods, the proportion of good outcomes did not change; however, the mortality rate significantly decreased from 19% in the first period to 11% and 9.2% in the second and third periods, respectively. The poor outcome was mainly caused by the significantly higher incidence of systemic complication and procedural complication in the first period and the significantly lower incidence of delayed ischemic neurological deficit in the third period. The elderly patients had significantly poorer clinical outcomes than the nonelderly ones. During the last 25 years, the age of patients with aneurysmal SAH has rapidly increased. The study results may contribute to the improvement of the treatment strategy of SAH in advanced countries with a rapidly aging population.

著者

Minato Shin-ichi

出版者

Springer Berlin / Heidelberg

雑誌

International Journal on Software Tools for Technology Transfer (ISSN:14332779)

巻号頁・発行日

vol.3, no.2, pp.156-170, 2001-05

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In many real-life problems, we are often faced with manipulating sets of combinations. In this article, we study a special type of ordered binary decision diagram (OBDD), called zero-suppressed BDDs (ZBDDs). This data structure represents sets of combinations more efficiently than using original OBDDs. We discuss the basic data structures and algorithms for manipulating ZBDDs in contrast with the original OBDDs. We also present some practical applications of ZBDDs, such as solving combinatorial problems with unate cube set algebra, logic synthesis methods, Petri net processing, etc. We show that a ZBDD is a useful option in OBDD techniques, suitable for a part of the practical applications.

著者

Keisuke NISHIMOTO Tomohiko OZAKI Tomoki KIDANI Shin NAKAJIMA Yonehiro KANEMURA Hiroki YAMAZAKI Toshiyuki FUJINAKA

出版者

The Japan Neurosurgical Society

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

pp.2022-0389, (Released:2023-06-08)

参考文献数

34

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Flow diverter (FD) stenting is expected to improve cranial nerve symptoms caused by aneurysms via the theoretical reduction of the mass effect by promoting spontaneous thrombosis through the flow diversion effect. However, the factors involved in symptom improvement after treatment remain unclear. This study was performed to identify factors for symptom improvement after FD stenting and the symptom improvement rate of each impaired cranial nerve. We retrospectively evaluated 33 patients who underwent FD stenting for symptomatic internal carotid artery aneurysms at our institution from January 2016 to June 2021. Twenty-three (69.7%) patients had resolved or improved symptoms after 1 year of treatment. The optic nerve was affected in 12 patients; the oculomotor nerve, in 16; the trigeminal nerve, in 2; and the abducens nerve, in 13. There was no statistically significant difference in the symptom improvement rate of each impaired cranial nerve. The patients were classified into the improved and nonimproved groups based on their symptoms after 1 year of treatment, and the factors related to the symptoms were analyzed. The time from onset to treatment was significantly shorter in the improved group than in the nonimproved group (197.1 and 800 days, respectively; p = 0.023). There were no significant differences in age, aneurysm diameter, adjunctive coil embolization, partial thrombosis, change in mass diameter on magnetic resonance imaging, or aneurysm occlusion rate on angiography between the two groups. These results suggest that early treatment after the onset of aneurysm-induced cranial neuropathies increases the likelihood of symptom improvement.

著者

Eisuke Kume Yuya Okayama Mituru Sugiyama Hiroyuki Takahashi Tomoko Muto Michael F. Wempe Hiroshi Ikegami Shin Wakui

出版者

The Japanese Society of Toxicology

雑誌

Fundamental Toxicological Sciences (ISSN:2189115X)

巻号頁・発行日

vol.10, no.3, pp.R1, 2023 (Released:2023-06-06)

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Editor’s Announcement Quantitative morphometric analysis of vimentin filaments in Sertoli cells of rats after in utero DBP exposureEisuke Kume, Yuya Okayama, Mituru Sugiyama, Hiroyuki Takahashi, Tomoko Muto, Michael F. Wempe, Hiroshi Ikegami, Shin Wakui(Fundamental Toxicological Sciences, 4, 85-93, 2017) I have retracted the above paper as Editor-in-Chief of Fundamental Toxicological Sciences since I have serious concerns about it, primarily due to inappropriate authorship on a non-negligible scale.Since the possibility of inappropriate authorship in this paper was raised, I contacted the co-authors to confirm this point. I found out that several of them considered their listing as co-authors to be inappropriate. In addition, more than half of the co-authors agreed to the retraction of this paper.These facts raise concerns about the paper. From the standpoint of maintaining the integrity of the research community, I felt that such a paper should be retracted at once.Accordingly, I sent a summary of my concerns about this paper to the corresponding author, Dr. Shin Wakui. I also had an online interview with him to discuss this matter. I told Dr. Wakui that inappropriate authorship on a non-negligible scale is a serious problem that raises concerns about the paper.I prepared a draft of this Editor’s Announcement and sent it to Dr. Wakui for review prior to revision and release. Although he did not agree to the retraction, I have decided to take this action from the standpoint of maintaining the integrity of the research community.I coordinated my response to this issue with Dr. Toshiyuki Kaji, Editor-in-Chief of The Journal of Toxicological Sciences, a sister journal of Fundamental Toxicological Sciences.Akira Naganuma, Ph.D.Editor-in-ChiefFundamental Toxicological Sciences

著者

Eisuke Kume Yuya Okayama Mituru Sugiyama Hiroyuki Takahashi Tomoko Muto Michael F. Wempe Hiroshi Ikegami Shin Wakui

出版者

The Japanese Society of Toxicology

雑誌

Fundamental Toxicological Sciences (ISSN:2189115X)

巻号頁・発行日

vol.4, no.2, pp.85-93, 2017-05-13 (Released:2017-05-13)

参考文献数

18

被引用文献数

1 1

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This article was retracted. See the Notification.

著者

Masaya Motohashi Michael F. Wempe Tomoko Mutou Yuya Okayama Norio Kansaku Hiroyuki Takahashi Masahiro Ikegami Masao Asari Shin Wakui

出版者

The Japanese Society of Toxicology

雑誌

The Journal of Toxicological Sciences (ISSN:03881350)

巻号頁・発行日

vol.48, no.6, pp.R1, 2023 (Released:2023-06-06)

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Editor’s AnnouncementIn utero-exposed di(n-butyl) phthalate induce dose dependent, age-related changes of morphology and testosterone-biosynthesis enzymes/associated proteins of Leydig cell mitochondria in ratsMasaya Motohashi, Michael F. Wempe, Tomoko Mutou, Yuya Okayama, Norio Kansaku, Hiroyuki Takahashi, Masahiro Ikegami, Masao Asari, Shin Wakui(The Journal of Toxicological Sciences, 41, 195-206, 2016) I have retracted the above paper as Editor-in-Chief of The Journal of Toxicological Sciences since I have serious concerns about it, primarily due to inappropriate authorship on a non-negligible scale.When it was brought to my attention that there was inappropriate authorship in this paper, I contacted the co-authors to confirm this point. I found out that the majority of them considered their listing as co-authors to be inappropriate. In addition, the majority agreed to the retraction of this paper.These facts raise concerns about the paper. From the standpoint of maintaining the integrity of the research community, I felt that such a paper should be retracted at once.Accordingly, I sent a summary of my concerns about the paper to the corresponding author, Dr. Shin Wakui. I also had an online interview with him to discuss this matter. I told Dr. Wakui that inappropriate authorship on a non-negligible scale is a serious problem that raises concerns about the paper.I prepared a draft of this Editor’s Announcement and sent it to Dr. Wakui for review prior to revision and release. Although he did not agree to the retraction, I have decided to take this action from the standpoint of maintaining the integrity of the research community.I coordinated my response to this issue with Dr. Akira Naganuma, Editor-in-Chief of Fundamental Toxicological Sciences, a sister journal of The Journal of Toxicological Sciences. Toshiyuki Kaji, Ph.D.Editor-in-ChiefThe Journal of Toxicological Sciences

著者

Masaya Motohashi Michael F. Wempe Tomoko Mutou Yuya Okayama Norio Kansaku Hiroyuki Takahashi Masahiro Ikegami Masao Asari Shin Wakui

出版者

The Japanese Society of Toxicology

雑誌

The Journal of Toxicological Sciences (ISSN:03881350)

巻号頁・発行日

vol.41, no.2, pp.195-206, 2016-04-01 (Released:2016-03-10)

参考文献数

36

被引用文献数

14 16

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This article was retracted. See the Notification.

著者

Kazufumi Nagata Yasunori Nonoue Kazuki Matsubara Ritsuko Mizobuchi Nozomi Ono Taeko Shibaya Kaworu Ebana Eri Ogiso-Tanaka Takanari Tanabata Kazuhiko Sugimoto Fumio Taguchi-Shiobara Jun-ichi Yonemaru Yusaku Uga Atsunori Fukuda Tadamasa Ueda Shin-ichi Yamamoto Utako Yamanouchi Toshiyuki Takai Takashi Ikka Katsuhiko Kondo Tomoki Hoshino Eiji Yamamoto Shunsuke Adachi Jian Sun Noriyuki Kuya Yuka Kitomi Ken Iijima Hideki Nagasaki Ayahiko Shomura Tatsumi Mizubayashi Noriyuki Kitazawa Kiyosumi Hori Tsuyu Ando Toshio Yamamoto Shuichi Fukuoka Masahiro Yano

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

vol.73, no.3, pp.332-342, 2023 (Released:2023-07-27)

参考文献数

64

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Many agronomic traits that are important in rice breeding are controlled by multiple genes. The extensive time and effort devoted so far to identifying and selecting such genes are still not enough to target multiple agronomic traits in practical breeding in Japan because of a lack of suitable plant materials in which to efficiently detect and validate beneficial alleles from diverse genetic resources. To facilitate the comprehensive analysis of genetic variation in agronomic traits among Asian cultivated rice, we developed 12 sets of chromosome segment substitution lines (CSSLs) with the japonica background, 11 of them in the same genetic background, using donors representing the genetic diversity of Asian cultivated rice. Using these materials, we overviewed the chromosomal locations of 1079 putative QTLs for seven agronomic traits and their allelic distribution in Asian cultivated rice through multiple linear regression analysis. The CSSLs will allow the effects of putative QTLs in the highly homogeneous japonica background to be validated.

著者

Kana Kurokawa Munechika Hara Shin-ichiro Iwakami Takuya Genda Naoko Iwakami Yosuke Miyashita Masahiro Fujioka Shinichi Sasaki Kazuhisa Takahashi

出版者

The Japanese Society of Internal Medicine

雑誌

Internal Medicine (ISSN:09182918)

巻号頁・発行日

vol.58, no.22, pp.3283-3287, 2019-11-15 (Released:2019-11-15)

参考文献数

23

被引用文献数

13 14

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The anti-programmed cell death-1 protein monoclonal antibody, pembrolizumab is an immune checkpoint inhibitor. While it improves the prognoses of patients with advanced non-small-cell lung cancer, it has been reported to induce various kinds of immune-related adverse events, including hepatotoxicity. Despite the frequency of hepatotoxicity, there is only limited information available regarding the pathophysiology and treatment. We herein report a 48-year-old man with lung adenocarcinoma who was treated with pembrolizumab and developed cholestatic liver injury. In this case, the importance of evaluating the histology of hepatotoxicity and the effectiveness of ursodeoxycholic acid for cholestatic liver injury is indicated.

著者

Nana Ushine Shouta MM Nakayama Mayumi Ishizuka Takuya Kato Shin-ichi Hayama

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.26, pp.25-37, 2023-06-22 (Released:2023-06-22)

参考文献数

83

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Lead (Pb) is extensively used in industries and often inadvertently discharged into the environment. Despite some studies examining the effects of Pb pollution on raptors and waterfowl, its effects on other avian species have not been investigated. This study investigated the feeding selectivity of a black-headed gull (Chroicocephalus ridibundus) population using stable isotope ratios to determine the source of Pb pollution. Gulls in Tokyo and Mikawa Bay were captured from December 2016 to February 2017 and from December 2020 to March 2021, respectively. These gulls were measured 13C/12C carbon ratio (δ13C), and 15N/14N nitrogen ratio (δ15N). Blood Pb level (BLL) was measured gulls in Mikawa Bay. Based on the measurement values of δ15N, gulls were classified into two groups: primary and higher predator groups. No differences in stable isotope ratios were found between the two groups. The secondary consumers showed significantly high BLLs (P=0.002). BLLs during the wintering period were significantly higher in the primary consumer group. Our findings suggest that reducing Pb emissions, along with biological and chemical remediation of water sediment is required to prevent further Pb pollution and bioaccumulation in wild animals.

著者

Duck Y. Hwang Yong M. Kim Dong H. Shin

出版者

The Japan Institute of Metals and Materials

雑誌

MATERIALS TRANSACTIONS (ISSN:13459678)

巻号頁・発行日

vol.50, no.3, pp.671-678, 2009-03-01 (Released:2009-02-25)

参考文献数

23

被引用文献数

39 46

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Plasma Electrolyte Oxidation (PEO) behavior of AZ91 Mg alloy was investigated in the electrolytes with/without potassium fluoride. Growth rate of coating thickness in the electrolyte containing potassium fluoride (Bath B) was much higher than that in the electrolyte without potassium fluoride (Bath A). The oxide layer formed on AZ91 Mg alloy in electrolyte with potassium fluoride and sodium silicate consisted of MgO, MgF2 and Mg2SiO4. Corrosion current density of oxide layer coated from the electrolyte with potassium fluoride was much lower than that of oxide layer coated from the electrolyte without potassium fluoride. From the result of EIS analysis, it was known that inner barrier layer in the oxide layer coated from the electrolyte with potassium fluoride had a good influence of the corrosion resistance of Mg alloy. The corrosion resistance curves of Bath B were similar to the thickness curves, indicating that the thickness of the oxide layer played an important role in corrosion resistance of AZ91 Mg alloy. The oxide layer in the Bath B containing potassium fluoride was found to be a compact barrier-type passive film in presence of fluoride ions. The existence of the dense MgO and MgF2 in the barrier layer had a favorable effect on the corrosion resistance of the AZ91 Mg alloy formed from Bath B by PEO process.

著者

Takako GOTOHDA Aki KUWADA Kyoji MORITA Shin-ichi KUBO Itsuo TOKUNAGA

出版者

The Japanese Society of Toxicology

雑誌

The Journal of Toxicological Sciences (ISSN:03881350)

巻号頁・発行日

vol.25, no.3, pp.223-231, 2000-08-17 (Released:2008-02-21)

参考文献数

39

被引用文献数

11 12

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Toluene, a commonly used industrial solvent, is known to be toxic to both neuronal and glial cells, and has been shown to increase the immunoreactivity of glial fibrillary acidic protein(GFAP)in the brain. However, the mechanism of toluene-induced GFAP expression is poorly understood. Recently, GFAP mRNA expression in cultured astrocytes has been shown to be modulated by various steroid hormones, such as progesterone, testosterone, and their 5α-reduced metabolites. Therefore, it seems possible that steroid hormones may play a potential role in the enhancement of GFAP expression observed following toluene exposure. To address this possibility, the effect of toluene inhalation on the expression of mRNAs encoding GFAP and steroidogenic enzymes in rat brain was examined. Toluene exposure increased GFAP protein contents without any significant alteration in GFAP mRNA levels in the hippocampus. In contrast, the elevation of both GFAP protein contents and its mRNA levels was observed in the cerebellum following toluene exposure. Further studies indicated that toluene exposure increased steroid 5α-reductase(5α-R)mRNA levels prior to the elevation of GFAP mRNA in the cerebellum, whereas neither 5α-R nor GFAP mRNA levels in the hippocampus were significantly affected by toluene exposure. These results suggest that toluene inhalation may enhance GFAP gene expression in the rat cerebellum, and propose the possibility that the elevation of 5α-R expression, and hence 5α-reduced metabolites of steroid hormones, is presumably related to toluene-induced GFAP mRNA expression.