Fluorescent molecular sensing for endocrine-disrupting chemicals and their analogs has been studied by investigating the fluorescence spectral change of regio-selective dansyl-tosyl-modified β- and ...γ-cyclodextrins upon the addition of a guest. These host compounds show pure monomer fluorescence at around 526 nm; the intensities of the guest-induced fluorescence either increase or decrease according to the accommodation of such guests as dioxin analogs, p-nonylphenol, 2,4-dichlorophenoxyacetic acid, bisphenol A, and diethylphthalate. The extent of the fluorescence variations with the guest is employed to display the sensing abilities of these hosts. The sensing parameter, ΔI/I 0 , was used to describe the sensing ability of the hosts, where I and I 0 are the fluorescence intensities in the presence and absence of a guest and ΔI=I-I 0. These hosts exhibit highly sensitive and selective molecular-recognition ability, particularly for 2,4,6-trichlorophenol and bisphenol A.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Using a portable near infrared (NIR) spectrometer, we discriminated flours for making Japanese noodles (Soba), not only relying on a statistical and mathematical approach, but also on a chemical ...interpretation of the NIR spectra. In original NIR spectra, the particle-size difference, which results in an undesired systematic variation, was extracted and interpreted as the first-principal component factor by a principal-component analysis. The discrimination of flour materials cannot be satisfied by this factor. However, after a standardized treatment for the original spectra, the particle-size effects were eliminated; alternatively, differences in the chemical contents were extracted as principal-component factors. Using these factors, flour material discrimination was achieved much better. This study suggests a novel idea of utilizing the wavelength contribution ratio spectra for interpreting the factors extracted from the principal-component analysis for the NIR spectra. This report also describes the relationship between the NIR spectra and the chemical-analysis data.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We investigated the effect of kinds of organic solvent on the losses of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs), coplanar polychlorinated biphenyls (Co-PCBs), and their ...13C12-labeled compounds during vacuum concentration. n-Hexane and toluene solutions containing the standards of those compounds were tested for the purpose. The kind of organic solvent has remarkable effect on the loss of 13C12-Co-PCBs from the standard solutions, while it has little or no effect on the losses of Co-PCBs, PCDD/DFs, and 13C12-PCDD/DFs from the standard solutions. The losses of lower chlorinated 13C12-Co- PCBs with n-hexane solution were greater than the loss of the compounds with toluene solution. The relative amounts of 13C12-Co-PCBs in the condensate solvent produced during the vacuum concentration show that those of the compounds with toluene solution were less than that of n-hexane solution. These results demonstrate that the minimization of loss of the compounds with n-hexane solution may be achieved by adding toluene before the vacuum concentration. We also examined the relationship between the relative amounts of Co-PCBs and 13C12-Co-PCBs in the condensate solvents and vapor pressures of those compounds. There was the difference in the regression line slopes of the relative amounts vs. in the vapor pressures between the n-hexane solution and toluene solution. This fact could be useful for the optimization of the vacuum concentration conditions in the convenient analytical methods.
Water-soluble
l-cysteine capped Mn-doped ZnS@Si quantum-dots (QDs), a kind of sensitizer, were synthesized. It was found that this sensitizer could enhance chemiluminescence (CL) signals emitted from ...interaction of NaClO with H
2O
2 in basic medium. The CL mechanism was studied experimentally by singlet oxygen (
1O
2) quenching method, UV–vis spectra, X-ray photoelectron spectra, transmission electron microscopy studies and ESR spin-trapping spectra. The results demonstrated that the CL enhancement of NaClO–H
2O
2 originate from the catalysis of the sensitizer, which catalyzed the decomposition of H
2O
2, producing reactive intermediates hydroxyl radical (
OH) and superoxide anion (O
2
−
). Then the resulting
OH reacted with O
2
−
to form
1O
2 and oxygen excimer species (
1O
2)
2
⁎, which rapidly returned to its ground state by passing its energy to the sensitizer through an electron-transfer process. Finally, the sensitizer being in excited state, returned to the ground state through enhanced CL-emission.
►
l-cysteine capped Mn-doped ZnS@Si QDs were synthesized to enhance the CL of NaClO–H
2O
2 system. ► Singlet oxygen and hydroxyl radical played key roles in the CL reaction process. ► An electron-transfer process occurred between excited dimol singlet oxygen and the QDs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Extraction solvents for pressurized liquid extraction (PLE) used to extract polychlorinated dibenzo-
p-dioxins, polychlorinated dibenzofurans (PCDD/PCDFs), and coplanar polychlorinated biphenyls ...(Co-PCBs) from contaminated soil were investigated. The PCDD/PCDFs and Co-PCBs in Certified Reference Material: CRM 0422 (Forest soil) were extracted using toluene,
n-hexane, acetone, acetone/toluene and acetone/
n-hexane (1:1, v/v). Soxhlet extraction was the reference method. Results demonstrated that PLE using mixed solvents produced better analyte recoveries than the single solvents. However, these results were lower than those for Soxhlet extraction. Additional extraction cycles using mixed solvents achieved better recovery results. Mixed solvents and several extraction cycles were necessary for satisfactory extraction of more tightly bound PCDD/PCDFs and Co-PCBs from soil.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Fog and rain water samples were collected at the same time in the Akita Hachimantai mountain range in northern Japan from June to September in 1998 and 1999. The various ion concentrations in these ...samples were analyzed, and the fog droplet sizes were measured for each fog event. As the fog droplet size increased, the ion concentration decreased. The slope of log-log plots of the concentration versus the droplet size differed with the kind of ion. In order to characterize the air pollutant, moreover, these data were quantitatively analyzed by an oblique rotational factor analysis. We found that three factors were extracted as the air pollutant source: (NH4)2SO4, acids (HNO3 + H2SO4) and sea-salt. Combining the factor analysis with the 72 h back-trajectory at 850 hPa level, we found that the contribution of each factor varied with the transport pattern of air masses.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Pressurized liquid extraction (PLE) was studied for simultaneous extractions of polychlorinated dibenzo-
p-dioxins and dibenzofurans (PCDD/PCDFs), and of coplanar polychlorinated biphenyls (Co-PCBs) ...from a tightly bounded condition in the soil matrix. Temperatures were maintained at 175 and 200
°C, respectively, and two or three static cycles for single PLE with toluene and acetone/
n-hexane were studied using a certified reference material to compare the effects of those conditions on recoveries. A single PLE with two static cycles at 150
°C and the repeated single PLE (additional PLE) were reference methods. Satisfactory recoveries were not obtained using tested single PLE (2,3,7,8-substituted PCDD/PCDFs and Co-PCBs average, average (avg.) 79–103%), but they were achieved using additional PLE (acetone/
n-hexane, avg. 115–128%; toluene, avg. 111–132%). In addition, these methods and additional PLE of the reference method using acetone/
n-hexane were not markedly different (avg. 123–128%). That fact suggests that the use of mixed solvents and additional PLE were more important factors than temperatures and static cycles of single PLE for quantitative and simultaneous extractions of those compounds from the soil.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We previously reported that gentamicin (GM) specifically binds to heat-shock protein with subunit molecular masses of 70kDa (HSP70). In the present study, we have investigated the effects of GM ...binding on HSP70-assisted protein folding in vitro. The C-terminal, and not the N-terminal of HSP70 was found to bind to GM. GM significantly suppressed refolding of firefly luciferase in the presence of HSP70 and HSP40, although the ATPase activity of HSP70 was unaffected by GM. A surface plasmon resonance analysis revealed that GM specifically interferes with the binding of HSP70 to a model peptide that mimics the exposed hydrophobic surface of the folding intermediates. These results indicated that GM inhibits the chaperone activity of HSP70 and may suppress protein folding via inhibition of HSP70 in vivo.
MINT-7384283: HSP40 (uniprotkb:P25685) binds (MI:0407) to HSP70 (uniprotkb:P34930) by surface plasmon resonance (MI:0107)
MINT-7384430: RNaseA (uniprotkb:P61823) binds (MI:0407) to HSP70 (uniprotkb:P34930) by surface plasmon resonance (MI:0107)
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BFBNIB, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
γ-Cyclodextrin dimer linked with ethylenediamine has been synthesized and then modified with dansyl moiety in the presence of N, N′-dicyclohexylcarbodiimide. The sensing ability and binding property ...of the titled compound are investigated for bile acids. The fluorescence intensity of the cyclodextrin dimer is decreased when a host-guest complex was formed. The value ΔΙ/Ι0 , where Ι and Ι0 are fluorescence intensities in the presence and absence of a guest and ΔΙ is Ι0-Ι, was used as a parameter of sensitivity. This host exhibits highly sensitive and selective molecular recognition ability for ursodeoxycholic acid, lithocholic acid and chenodeoxycholic acid. The behaviors of appended moieties of the host when a host-guest complexation is occurring were studied by induced circular dichroism (ICD) and fluorescence spectra. The ICD spectra patterns of the titled dimer were opposite to those of bis dansyl-modified γ-CyD reported previously. The guest-induced variations in the fluorescence and ICD intensity suggest that the appended moieties work as a hydrophobic cap.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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