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排序方式: 共有286条查询结果,搜索用时 15 毫秒
31.
S J Logusch P C Feng H Fujiwara W C Hutton S J Wratten 《Journal of agricultural and food chemistry》1999,47(5):2125-2129
Rat liver tissue homogenates were utilized for in vitro enzymatic conversion of 2,6-diethylaniline (DEA) to the important alachlor metabolite 4-amino-3,5-diethylphenyl sulfate (ADEPS), which was also generated as a radiolabeled standard for use in metabolism studies. ADEPS formation in rodents is associated with the production of other reactive metabolites implicated in alachlor rodent carcinogenesis, making dependable access to an ADEPS standard highly desirable. (14)C-DEA was oxidized by rat liver microsomes to (14)C-4-amino-3,5-diethylphenol, which was further converted to ADEPS via addition of the phosphosulfate transferase cofactor adenosine-3'-phosphate-5'-phosphosulfate. Microprobe NMR was used in conjunction with high-resolution mass spectrometry to fully characterize the resulting (14)C-ADEPS and confirm its structure. Because microgram quantities sufficed for full characterization, the enzymatic transformation provides a viable alternative to radiosynthesis of (14)C-ADEPS. 相似文献
32.
K Iizasa RS Fiske O Ishizuka M Yuasa J Hashimoto J Ishibashi J Naka Y Horii Y Fujiwara A Imai S Koyama 《Science (New York, N.Y.)》1999,283(5404):975-977
Manned submersible studies have delineated a large and actively growing Kuroko-type volcanogenic massive sulfide deposit 400 kilometers south of Tokyo in Myojin Knoll submarine caldera. The sulfide body is located on the caldera floor at a depth of 1210 to 1360 meters, has an area of 400 by 400 by 30 meters, and is notably rich in gold and silver. The discovery of a large Kuroko-type polymetallic sulfide deposit in this arc-front caldera raises the possibility that the numerous unexplored submarine silicic calderas elsewhere might have similar deposits. 相似文献
33.
Visible quantum cutting in LiGdF4:Eu3+ through downconversion 总被引:1,自引:0,他引:1
For mercury-free fluorescent lamps and plasma display panels, alternative luminescent materials are required for the efficient conversion of vacuum ultraviolet radiation to visible light. Quantum cutting involving the emission of two visible photons for each vacuum ultraviolet photon absorbed is demonstrated in Eu3+-doped LiGdF4 with the concept of downconversion. Upon excitation of Gd3+ with a high-energy photon, two visible photons can be emitted by Eu3+ through an efficient two-step energy transfer from Gd3+ to Eu3+, with a quantum efficiency that approaches 200 percent. 相似文献
34.
Sakiko Orui Sakaguchi Shigeru Shimamura Yuichi Shimizu Gen Ogawa Yuichiro Yamada Keiko Shimizu Hiroaki Kasai Hiroshi Kitazato Yoshihiro Fujiwara Katsunori Fujikura Kiyotaka Takishita 《Fisheries Science》2017,83(1):47-56
To identify the stomach contents of marine organisms, morphological observations are commonly conducted. However, the results obtained by this traditional method are frequently biased, as it is difficult to detect partially digested, soft-bodied organisms. To resolve this, recent studies have used DNA-based (DNA barcoding) analyses to examine the diet breadth of marine organisms. Here, we compared the prey richness of juvenile fishes using morphological observations and DNA-based analyses, with a focus on juvenile chum salmon Oncorhynchus keta. A higher number of prey taxa were successfully identified using DNA-based analyses than morphological observations. However, we also noticed several shortcomings of the DNA-based analyses, as reported in other diet-analysis studies that used molecular techniques. For example, the degree of digestion among prey taxa might have resulted in differential sensitivity to DNA detection. Additionally, several prey taxa could not be precisely identified, as the sequence data for some of the targeted organismal groups are unavailable in public gene databases. Remarkably, it is also possible that DNA-based analyses detected secondary prey, and therefore, the richness of prey taxa was likely overestimated. Thus, dietary analyses of juvenile fishes need to be carefully conducted, considering the respective advantages and disadvantages of DNA-based and morphological techniques. 相似文献
35.
Carlos Montez Wells Emily Carol Coleman Rabeta Yeasmin Zoe Lynn Harrison Mallesh Kurakula Daniel L. Baker Joel David Bumgardner Tomoko Fujiwara Jessica Amber Jennings 《Marine drugs》2021,19(10)
Chitosan nanofiber membranes are recognized as functional antimicrobial materials, as they can effectively provide a barrier that guides tissue growth and supports healing. Methods to stabilize nanofibers in aqueous solutions include acylation with fatty acids. Modification with fatty acids that also have antimicrobial and biofilm-resistant properties may be particularly beneficial in tissue regeneration applications. This study investigated the ability to customize the fatty acid attachment by acyl chlorides to include antimicrobial 2-decenoic acid. Synthesis of 2-decenoyl chloride was followed by acylation of electrospun chitosan membranes in pyridine. Physicochemical properties were characterized through scanning electron microscopy, FTIR, contact angle, and thermogravimetric analysis. The ability of membranes to resist biofilm formation by S. aureus and P. aeruginosa was evaluated by direct inoculation. Cytocompatibility was evaluated by adding membranes to cultures of NIH3T3 fibroblast cells. Acylation with chlorides stabilized nanofibers in aqueous media without significant swelling of fibers and increased hydrophobicity of the membranes. Acyl-modified membranes reduced both S. aureus and P. aeruginosa bacterial biofilm formation on membrane while also supporting fibroblast growth. Acylated chitosan membranes may be useful as wound dressings, guided regeneration scaffolds, local drug delivery, or filtration. 相似文献
36.
Imtiaj Hasan Shigeki Sugawara Yuki Fujii Yasuhiro Koide Daiki Terada Naoya Iimura Toshiyuki Fujiwara Keisuke G. Takahashi Nobuhiko Kojima Sultana Rajia Sarkar M. A. Kawsar Robert A. Kanaly Hideho Uchiyama Masahiro Hosono Yukiko Ogawa Hideaki Fujita Jiharu Hamako Taei Matsui Yasuhiro Ozeki 《Marine drugs》2015,13(12):7377-7389
MytiLec; a novel lectin isolated from the Mediterranean mussel (Mytilus galloprovincialis); shows strong binding affinity to globotriose (Gb3: Galα1-4Galβ1-4Glc). MytiLec revealed β-trefoil folding as also found in the ricin B-subunit type (R-type) lectin family, although the amino acid sequences were quite different. Classification of R-type lectin family members therefore needs to be based on conformation as well as on primary structure. MytiLec specifically killed Burkitt''s lymphoma Ramos cells, which express Gb3. Fluorescein-labeling assay revealed that MytiLec was incorporated inside the cells. MytiLec treatment of Ramos cells resulted in activation of both classical MAPK/ extracellular signal-regulated kinase and extracellular signal-regulated kinase (MEK-ERK) and stress-activated (p38 kinase and JNK) Mitogen-activated protein kinases (MAPK) pathways. In the cells, MytiLec treatment triggered expression of tumor necrosis factor (TNF)-α (a ligand of death receptor-dependent apoptosis) and activation of mitochondria-controlling caspase-9 (initiator caspase) and caspase-3 (activator caspase). Experiments using the specific MEK inhibitor U0126 showed that MytiLec-induced phosphorylation of the MEK-ERK pathway up-regulated expression of the cyclin-dependent kinase inhibitor p21, leading to cell cycle arrest and TNF-α production. Activation of caspase-3 by MytiLec appeared to be regulated by multiple different pathways. Our findings, taken together, indicate that the novel R-type lectin MytiLec initiates programmed cell death of Burkitt’s lymphoma cells through multiple pathways (MAPK cascade, death receptor signaling; caspase activation) based on interaction of the lectin with Gb3-containing glycosphingolipid-enriched microdomains on the cell surface. 相似文献
37.
K. Fukunaga M. Saito E. Matsuo M. Muto K. Mishima M. Fujiwara K. Orito 《Research in veterinary science》2009,87(3):455-457
We investigated how long in vivo hepatic cytochrome P450 (CYP) activity is enhanced even after discontinuation of repeated oral administration of phenobarbital (PB) in dogs using antipyrine clearance, which reflects hepatic CYP activity. A single antipyrine (5 mg/kg) was administered intravenously before and 34 days after the repeated oral administration of PB (5 mg/kg, bid) and 2, 4, 6, and 8 weeks after the discontinuation of PB in 5 dogs. Antipyrine clearance was increased by the repeated administration of PB, and remained increased 2 and 4, but not 6 and 8 weeks after the discontinuation of PB. The result suggests that hepatic CYP activity was enhanced by the repeated administration of PB, and this enhancement may last for at least 4 weeks even after its discontinuation. 相似文献
38.
Cadmium transport and tolerance in rice: perspectives for reducing grain cadmium accumulation 总被引:2,自引:0,他引:2
Cadmium (Cd) is a toxic heavy metal which harms human health. In Japan, a major source of human Cd-intake is rice grains and contamination of paddy soils by Cd and accumulation of Cd in rice grains are the serious agricultural issues. There also exist Cd contamination of rice and its toxicity in several populations in countries including China and Thailand. Understanding the Cd transport mechanisms in rice can be a basis for regulating rice Cd transport and accumulation by molecular engineering and marker-assisted breeding. Recently, a number of studies have revealed the behavior of Cd in rice, genetic diversity of Cd accumulation, quantitative trait loci controlling Cd accumulation and transporter molecules regulating Cd accumulation and distribution in rice. In this article, we summarize recent advances in the field and discuss perspectives to reduce grain Cd contents. 相似文献
39.
Comparisons among MRI signs,apparent diffusion coefficient,and fractional anisotropy in dogs with a solitary intracranial meningioma or histiocytic sarcoma
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Masae Wada Daisuke Hasegawa Yuji Hamamoto Yoshihiko Yu Aki Fujiwara‐Igarashi Michio Fujita 《Veterinary radiology & ultrasound》2017,58(4):422-432
Although MRI has become widely used in small animal practice, little is known about the validity of advanced MRI techniques such as diffusion‐weighted imaging and diffusion tensor imaging. The aim of this retrospective analytical observational study was to investigate the characteristics of diffusion parameters, that is the apparent diffusion coefficient and fractional anisotropy, in dogs with a solitary intracranial meningioma or histiocytic sarcoma. Dogs were included based on the performance of diffusion MRI and histological confirmation. Statistical analyses were performed to compare apparent diffusion coefficient and fractional anisotropy for the two types of tumor in the intra‐ and peritumoral regions. Eleven cases with meningioma and six with histiocytic sarcoma satisfied the inclusion criteria. Significant differences in apparent diffusion coefficient value (× 10?3 mm2/s) between meningioma vs. histiocytic sarcoma were recognized in intratumoral small (1.07 vs. 0.76) and large (1.04 vs. 0.77) regions of interest, in the peritumoral margin (0.93 vs. 1.08), and in the T2 high region (1.21 vs. 1.41). Significant differences in fractional anisotropy values were found in the peritumoral margin (0.29 vs. 0.24) and the T2 high region (0.24 vs. 0.17). The current study identified differences in measurements of apparent diffusion coefficient and fractional anisotropy for meningioma and histiocytic sarcoma in a small sample of dogs. In addition, we observed that all cases of intracranial histiocytic sarcoma showed leptomeningeal enhancement and/or mass formation invading into the sulci in the contrast study. Future studies are needed to determine the sensitivity of these imaging characteristics for differentiating between these tumor types. 相似文献
40.
Odor is one of the most important characteristics affecting consumer preference for dried shiitake mushrooms [Lentinula edodes (Berk.) Pegler]. In our previous studies, we found that the odor content of commercial dried products was too weak for most
people, and that the odorous compound content could be increased by adding amino acids to sawdust media. Currently, however,
bed-log cultivation is used to produce fruiting bodies for dried products. The purpose of this study was to fi nd a method
to increase the content of odorous compounds in dried products cultivated on bed logs. Pressure injection of amino acids from
the side of the bed log was the most effi cient method, but it had some problems. Hence, a simpler and less troublesome method
was developed, i.e., injecting amino acid solution from small bottles set in deep holes bored in the sides of the bed logs.
In fruiting bodies cultivated on bed logs injected with amino acid solution by the improved method, the mean contents of lentinic
acid, a precursor of the odorous compound lenthionine, approximately doubled compared to that in the untreated logs, although
the infi ltration area of the solution injected by the improved method was smaller than that by the former method. 相似文献