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1.
Ueyama J Saito I Kondo T Taki T Kimata A Saito S Ito Y Murata K Iwata T Gotoh M Shibata E Wakusawa S Kamijima M 《Chemosphere》2012,87(11):1403-1409
A recent development in analytical chemistry has enabled us to monitor systemic organophosphorus insecticide (OP) exposure at individual levels. At present, however, limited data are currently available on urinary OP metabolite levels worldwide. The purpose of this study was to assess urinary dialkylphosphate (DAP) concentrations in Japanese workers. Urine samples were collected in both summer and winter from 339 Japanese adults who worked as food distributors (FDs, n = 164), apple farmers (AFs, n = 147) and pest control operators (PCOs, n = 28). DAPs were measured by gas chromatography-mass spectrometry after derivatization with pentafluorobenzylbromide. Dimethylphosphate (DMP), diethylphosphate (DEP), dimethylthiophosphate (DMTP) and diethylthiophosphate (DETP) were detected in the urine of over 87% of the studied populations in both seasons. The geometric mean values of total DAPs (nmol g−1 creatinine), DMP, DMTP, DEP and DETP (μg g−1 creatinine) in summer and winter were 106.7 and 98.3, 7.0 and 3.8, 3.4 and 4.5, 0.8 and 1.5, and 0.3 and 0.2 for the FDs, 440.8 and 197.7, 33.1 and 10.8, 10.1 and 5.8, 4.2 and 4.7 and 1.6 and 0.8 for the AFs, and 473.4 and 284.6, 28.9 and 22.2, 17.6 and 4.6, 3.5 and 4.4, and 0.5 and 0.6 for the PCOs, respectively, thereby revealing significantly higher concentrations in AFs and PCOs groups than in the FDs in both seasons except for winter DMTP. These DAP concentrations were approximately the same or at lower levels compared with those reported in the previous literature. This is one of the first studies to demonstrate urinary DAP concentrations in Japanese adults. 相似文献
2.
Kiyoko M. Gotanda Katrine Turgeon Donald L. Kramer 《Behavioral ecology and sociobiology》2009,63(11):1563-1572
Flight initiation distance (FID), the distance at which an organism begins to flee an approaching threat, is an important
component of antipredator behavior and a potential indicator of an animal’s perception of threat. In a field study on parrotfishes,
we tested the predictions that FID in response to a diver will increase with body size, a correlate of reproductive value,
and with experience of threat from humans. We studied a broad size range in four species on fringing reefs inside and outside
the Barbados Marine Reserve. We used the Akaike's Information Criterion modified for small sample sizes (AICc) and model averaging
to select and assess alternative models. Body size, reserve protection, and distance to a refuge, but not species, had strong
support in explaining FID. FID increased with body size and generally remained two to ten times fish total length. FID was
greater outside the reserve, especially in larger fish. Although we were not able to completely rule out other effects of
size or reserve, this study supports predictions of an increase in FID with reproductive value and threat from humans. 相似文献
3.
Mifuyu Ogawa Yuichi Yamaura Shin Abe Daisuke Hoshino Kazuhiko Hoshizaki Shigeo Iida Toshio Katsuki Takashi Masaki Kaoru Niiyama Satoshi Saito Takeshi Sakai Hisashi Sugita Hiroyuki Tanouchi Tatsuya Amano Hisatomo Taki Kimiko Okabe 《Environmental monitoring and assessment》2011,177(1-4):85-94
An alkaline comet assay and a micronucleus test were carried out on erythrocytes of the European chub, Squalius cephalus L., collected in spring and autumn in 2005 and 2006 at three sampling sites in River Sava, near Zagreb, Croatia. The results of comet assay showed the lowest genotoxic influence at the least polluted site, while higher DNA damage was observed at the polluted sites. Although the basal levels of DNA damage were elevated, a clear gradation of DNA damage was found due to pollution intensity in all sampling periods. The lowest cytogenetic damage as revealed by the micronucleus test (MNT) was observed as well at the least polluted site. High variations in MN frequency were observed between sampling periods, although the number of micronucleated erythrocytes was consistently the highest one at the polluted site. The comet assay as a biomarker of genotoxic effect exhibited higher sensitivity in discriminating the genotoxic capacity of studied polluted sites while the MNT was less sensitive. However, both tests should be used together in biomonitoring studies because they can reveal different aspects of DNA damage; comet assay, the early event of genotoxic exposure, and MNT, its final result as a mutagenic potential. 相似文献
4.
Michihiro Kitagawa Kentaro Sugiura Hiroko Omi Yoshiaki Akiyama Kiyoko Kanayama Masaru Shinya Tadao Tanaka Hirobumi Yura Haruhiko Sago 《黑龙江环境通报》2002,22(1):17-21
To isolate fetal cells from maternal blood, we developed a new method based on galactose-bearing conjugation. Nucleated red blood cells (NRBCs), which highly express galactose on their surface, were selectively attached to a substrate coated with a galactose-containing polymer via soybean agglutinin (SBA), a galactose-specific lectin. Cord blood samples were used to evaluate enrichment efficacy of NRBCs by this method. Blood samples were obtained from 131 pregnant women between 6 and 27 gestational weeks. After preliminary condensation of fetal cells by Ficoll gradient centrifugation, NRBCs were enriched using galactose-positive selection by adjusting SBA concentration. We isolated one to severalhundred NRBCs (mean±SD, 7.8±8.5) in 2.3 ml of peripheral blood samples from 96% of pregnantwomen. The isolated NRBCs were analyzed by a Y-chromosome FISH probe in eight cases carrying male fetuses. Y-signals were detected in all eight cases and more than half of the NRBCs wereoffetal origin. The study demonstrates that our new method using galactose-specific lectin provides effective enrichment of fetal NRBCs allowing non-invasive prenatal diagnosis. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Yoshimasa Amano Yusuke Sakai Takumi Sekiy Kimitaka Takey Kazuo Taki Motoi Machida 《环境科学学报(英文版)》2010,22(11):1666-1673
Tega-numa (Lake Tega) is one of the eutrophic lakes in Japan. For the improvement of water quality in Lake Tega, the Northchiba
Water Conveyance Channel was constructed in 2000, which transfer water from Tone River into the lake. After 2000, the
dominant species of diatoms, mainly Cyclotella sp., have been replacing blue-green algae, mainly Microcystis aeruginosa in Lake
Tega. This transition of dominant species would be due to the dilution, but the detail mechanism has not been understood yet. This
study examined the relationship between phosphorus fluctuation caused by river water dilution to Lake Tega and dominance of algal
species, M. aeruginosa or Cyclotella sp. based on the single-species and the mixed-species culture experiments. The single-species
culture experiment showed that the half-saturation constant and uptake rate of phosphorus were one order lower and seven times higher
for M. aeruginosa than those for Cyclotella sp. These findings implied that M. aeruginosa would possess a potential for the growth
and survival over Cyclotella sp. in the phosphorus limited condition. The superiority of M. aeruginosa was reflected in the outcome of
the mixed-species culture experiment, i.e., dominance of M. aeruginosa, even phosphorus concentration was lowered to 0.01 mg-P/L.
Therefore, it could be concluded that the decrease in phosphorus concentration due to the river water dilution to Lake Tega would be
interpreted as a minor factor for the transition of dominant species from M. aeruginosa to Cyclotella sp. 相似文献
7.
S. Hirota M. Matsuura H. Masuda A. Ushiyama K. Wake S. Watanabe M. Taki C. Ohkubo 《The Environmentalist》2009,29(2):186-189
A cranial window method modified for our experiment enabled to observe the cerebral microcirculation including the blood-brain
barrier permeability after a local expose to radio-frequency electromagnetic fields with a monopole antenna in rats. The present
report reviews our recent publications that reported no noticeable changes in the cerebral microcirculatory parameters due
to RF-EMF exposure. 相似文献
8.
We examined larval mesopelagic fish assemblages, their distribution, and seasonal occurrence patterns in the Kuroshio–Oyashio
transition region of the western North Pacific where complex hydrographic structures are observed due to the confluence of
the Kuroshio Extension and Oyashio current. Larvae of the dominant families Myctophidae, Gonostomatidae, Bathylagidae, Sternoptychidae,
and Phosichthyidae were represented by 31 species or types belonging to 24 genera. Based on species composition analysis using
the Morishita–Horn similarity index, five assemblages were recognized: Oyashio, Spring Transition, Summer Transition, Kuroshio,
and Slope Water assemblages. The distribution patterns of these assemblages corresponded closely with hydrographic structures
such as position of the Oyashio and Kuroshio Extension fronts, warm core rings and streamers. Spring Transition (April) and
Summer Transition (July–October) assemblages were the most important larval assemblages in the transition region. Larval abundances
were low during late autumn and winter. The Spring Transition and Summer Transition assemblages were composed of subtropical,
transitional, subarctic, and slope-water species, suggesting the importance of the transition region as nursery grounds of
mesopelagic fishes of various origins from subarctic to subtropical waters. Larval fish transport by the Kuroshio, Oyashio,
and Tsugaru Warm currents into the transition region is discussed. 相似文献
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A. Ushiyama H. Masuda S. Hirota K. Wake H. Kawai S. Watanabe M. Taki C. Ohkubo 《The Environmentalist》2007,27(4):489-492
Concerns on health effects of radiofrequency (RF) signals have been discussed. Particularly, the effect on the central nerve
system is one of main interest among the general public. So far, there are lots of studies regarding the RF effect on the
Blood Brain Barrier (BBB), but no study of the RF effect on the Blood Cerebrospinal fluid Barrier (BCB). In this study we
explored the effect on BCB function by radiofrequency electromagnetic fields (RF-EMF) exposure. To attain this purpose, we
set about to make a real-time measuring system for BCB function using a micro-perfusion method and examined the short time
exposure experiment using rats. Our data suggested the 30 min single exposure of 1.5 GHz RF-EMF at the brain average SARs
of 9.5 W/kg for adult and 10.4 W/kg for juvenile, did not affect BCB function in rats under the experimental conditions. 相似文献