184 research outputs found
An 8-sulfonamidoquinoline derivative with imidazolium unit as an extraction reagent for use in ionic liquid chelate extraction systems
金沢大学理工研究域物質化学系To evaluate the superiority of using a task-specific onium salt (TSOS), a novel TSOS reagent 1-methyl-3-[2-(8-quinolinylaminosulfonyl)ethyl]imidazolium chloride (HmimesqCl) was synthesized, and its performance in extraction of different divalent metal cations was investigated. This TSOS reagent has both a cationic imidazolium unit and an anionic (proton-dissociable) complexation unit for the extraction of metal cations into an ionic liquid. In the use of HmimesqCl, relatively high extraction of metals resulted in comparison with the use of its non-imidazolium analogs, without changing the extraction selectivity. © 2010 Elsevier B.V
Capillary Electrophoretic Characterization of Carbon Nanodots Prepared from Glutamic Acid in an Electric Furnace
Carbon nanodots (CNDs) prepared from glutamic acid or glutathione in an electric furnace were characterized by capillary electrophoresis. Two major peaks were detected in the electropherograms by capillary zone electrophoresis, corresponding to anionic and less-charged CNDs. The effective electrophoretic mobility of the anionic CND formed from glutamic acid was almost identical over neutral to weakly alkaline pH range, and the CND would not contain significant amount of amino group. On the other hand, the effective electrophoretic mobility tended to decrease with decreasing pH at weakly acidic pH conditions, suggesting the functional groups of carboxylate moiety on the anionic CNDs. Dodecyl sulfate ion was added in the separation buffer to give anionic charge to the less-charged CND by adsorption. However, the anionic charge induced was little, and the dodecyl sulfate ion was not likely adsorbed on the less-charged CND and the CND would be hydrophilic
Time-resolved measurements of two-color laser light emitted from GaAs/AlGaAs-coupled multilayer cavity
We measured the two-color laser oscillation from a GaAs/AlGaAs-coupled multilayer cavity at 18–42 °C using current injection. We confirmed simultaneous lasing by detecting the sum frequency generation signal generated by the two-color laser light, and performed time-resolved measurement using a streak camera with a spectrometer. From the observed time transient of the spectra at various temperatures, it it is clarified that the temperature change of the device, induced by current injection, modulates the effective cavity length. Therefore, the temperature control of the device is a key factor in stable two-color lasing and THz wave generation
Spectroelectrochemical characterization of dendrimer-porphyrin associates at polarized liquid|liquid interfaces
Molecular encapsulation of anionic porphyrins in NH2-terminated polyamidoamine (PAMAM) dendrimers and the interfacial behavior of the dendrimer-porphyrin associates were studied at the polarized water|1,2-dichloroethane (DCE) interface. Formation of the ion associates was significantly dependent on the pH condition and on generation of dendrimers. 5,10,15,20-Tetrakis(4-sulfonatophenyl)porphyrin (ZnTPPS4-) associated with the positively charged fourth-generation (G4) PAMAM dendrimer was highly stabilized in acidic aqueous solution without protolytic demetalation in a wide range of pH values (pH > 2). In contrast to the zinc(II) complex, the free base porphyrin (H2TPPS4-) was readily protonated under acidic conditions even in the presence of the dendrimers. In addition, the J-aggregates of diprotonated species, (H4TPPS2-) n, were preferably formed on the dendrimer. The interfacial mechanism of the dendrimer-porphyrin associates was analyzed in detail by potential-modulated fluorescence (PMF) spectroscopy. PMF results indicated that the dendrimers incorporating porphyrin molecules were transferred across the positively polarized water|DCE interface via adsorption step, whereas the transfer responses of the porphyrin ions released from the dendrimers were observed at negatively polarized conditions. A negative shift of the transfer potential of porphyrin ions compared to the intrinsic transfer potential was apparently observed for each ion association system. The ion association stability between the dendrimer and the porphyrin molecules could be estimated from a negative shift of the transfer potential. ZnTPPS4- exhibited relatively strong interaction with the higher generation dendrimer, whereas H2TPPS4- was less effectively associated with the dendrimers. © 2014 American Chemical Society
Extraction of Cu(II) with dioctyldithiocarbamate and a kinetic study of the extraction using a two-phase microflow system
金沢大学理工研究域物質化学系Extraction of Cu(II) with dialkyldithiocarbamates and the extraction kinetics have been studied using a two-phase microflow system. The extraction behavior of Cu(II) with potassium dioctyldithiocarbamate (Kdodtc) was investigated using a batch method to determine the propertes of the synthesized Kdodtc. The extraction ability of dodtc was much greater than that of diethyldithiocarbamate (dedtc) under acid conditions. On the other hand, at higher pH values in the range of 8 - 13, the extraction of Cu(II) with dodtc decreased with increasing pH. This phenomenon was ascribed to the formation of micelles and/or an emulsion, which was caused by the amphiphilic properties of dodtc. The extraction kinetics of Cu(II) was investigated using a glass microchip which was connected to microsyringe pumps and a UV/Vis capillary LC detector. The initial rate constant (kapp) determined for dodtc was greater than that with dedtc. From the relationship between the dodtc concentration and kapp, it was suggested that the extraction rate was governed by the formation of the dodtc complex at the liquid-liquid interface
Potential-Dependent Adsorption and Orientation of meso-Substituted Porphyrins at Liquid|Liquid Interfaces Studied by Polarization-Modulation Total Internal Reflection Fluorescence Spectroscopy
Potential-dependent adsorption behavior of meso-substituted water-soluble porphyrins at the polarized water|1,2-dichloroethane (DCE) interface was studied by polarization-modulation total internal reflection fluorescence (PM-TIRF) spectroscopy. In the PM-TIRF experiments, the fluorescence signal from the interfacial region was analyzed as a function of the periodic modulation of linear-polarizations (p and s) of the incident excitation beam. The potential-dependence of PM-TIRF responses for meso-substituted porphyrins, 5,10,15,20-tetrakis(N-methylpyridyl)porphyrin (H2TMPyP4+) and 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (H2TPPS4-), indicated that both free base porphyrins were adsorbed with relatively lying orientations at the polarized water|DCE interface. The average orientation angles (θ) were estimated as θ = 61 ± 1°for H2TMPyP4+ and θ = 65 ± 1°for H2TPPS4- with respect to the interface normal. The wavelength-dependence of polarization-modulated fluorescence signals (PM-TIRF spectrum), which corresponds to "pure" emission spectrum of interfacial species, clearly indicated that H2TMPyP4+ and H2TPPS4- are adsorbed with a modification of the solvation at the interface. These results demonstrated a high ability of the PM-TIRF spectroscopy for the direct characterization of fluorescent species adsorbed at polarized liquid|liquid interfaces. © 2016 American Chemical Society.Embargo Period 12 months / This article has Supplementary dat
A quantitative comparison of fish assemblage between amacroalgae bed and an adjoining sandy beach in the central Seto Inland Sea
植生の有無が魚類群集に与える影響を明らかにすることを目的として,瀬戸内海中央部の無人島(小久野島)の東岸において隣接するガラモ場と砂浜の魚類相調査を実施した。ガラモ場と砂浜に10m四方(面積100m2)の調査区画を各4ヶ所設定し,季節に1回の頻度で(2006年8月,11月,2007年2月,5月)小型巻網(目合い4mm)を用いて区画内の魚類をすべて採集した。一年間の調査により,ガラモ場で20種以上1,397個体,砂浜で17種以上902個体の魚類が採集された。個体数にもとづく優占種(上位3種)は,ガラモ場ではシロメバル,ヒメハゼ,ハオコゼ,砂浜ではヒメハゼ,ボラ,スジハゼ,湿重量にもとづく優占種は,ガラモ場ではシロメバル,ハオコゼ,キュウセン,砂浜ではヒメハゼ,シロギス,ボラであった。100m2あたりの出現種数,個体密度,バイオマスはいずれもガラモ場において大きな季節変動を示した。8月にはガラモ場における種数が砂浜よりも有意に多かった。ガラモ場においては,ホンダワラ類の繁茂期である2-5月にシロメバル仔稚魚の来遊にともなう個体密度とバイオマスの急増が認められた。Biological and physical surveys were conducted at amacloalgae bed (MB) and a sandy beach (SB) off an inhabited island in the central Seto Inland Sea, Japan, from August 2006 tomay 2007 in order to detect the effect of vegetation on fish assemblage. Fish were collected using a seine net (2m in height, 3mm in mesh aperture) at four separate locations within MB and SB during a tidal level between 70-130 cm in daytime on 4 Aug. and 16 Nov. 2006 and 19 Feb. and 2 May 2007. A total of 1,397 and 902 fish were collected at MB and SB, respectively. The numerically dominant species were Sebastes cheni, Favonigobius gymnauchen and Hypodytes rubripinnis in MB and Favonigobius gymnauchen, mugil cephalus cephalus and Acentrogobius pflaumii in SB. Weight-based dominant species were Sebastes cheni, Hypodytes rubripinnis and Halichoeres poecilopterus in MB and Favonigobius gymnauchen, Sillago japonica and Mugil cephalus cephalus. Seasonal fluctuation in number of fish species, fish abundance and biomass in MB were larger than those in SB.
The number of fish species in August in MB was significantly higher than that in SB. Fish abundance and biomass in MB abruptly increased fromFebruary to May due to immigration of S. cheni larvae and juveniles
Estimation of catch efficiency of a small seine for larval and juvenile Japanese sea bass, Lateolabrax japonicus, in the Ohta estuary
河口域における魚類群集の主要構成者であるスズキ仔稚魚に対する小型曳き網(幅2.3m,高さ1m)の採集効率を,地曳き網(幅16m,高さ1m)による採集結果と比較することにより推定した。2008年3月21日と4月7日に太田川放水路感潮域において合計15回の曳網を行い,合計1,502個体(標準体長14.5-24.0mm)のスズキ仔稚魚を採集した。地曳き網の網目からの逸出が生じる体長16mm未満と,個体密度が著しく低下する23mm以上については解析対象とせず,地曳き網による採集効率を100%と仮定した。体長1mmごとに区分した分布密度を採集具間で比較した結果,小型曳き網による体長16mm以上18mm未満のスズキ仔稚魚採集効率は約100%と推定された。体長18mm以上23mm未満では採集効率(C, %)が体長(L, mm)に比例して直線的に減少した(C=-17.2*L+388.8,n=11,r2=0.77,p=0.0004)。In order to estimate catch efficiency of a small seine (1.0 by 2.3 m, 2 mm mesh aperture) for larval and juvenile Japanese sea bass Lateolabrax japonicus, results from experimental hauls of the small seine were compared with those from a large seines (1.0 by 16 m, 2.5 mm mesh aperture) in the Ohta Diversion Channel on March 21 and April 7, 2008. A total of 1,502 Japanese sea bass, ranging between 14.5 and 24.0 mm in standard length were collected. Data of fish <15.9 mm was excluded from the analysis since extrusion of these fish through the mesh of the large seine was possible. Comparison of the Japanese sea bass abundance at lengths between the small and large seines revealed that the catch efficiency of the small seine for Japanese sea bass <18.0 mm was approximately 100%. The catch efficiency decreased with the increase in fish body length between 18.0 and 22.9 mm. A linear model was fitted to the relationship between the catch efficiency (C, %) and body length (L, mm): C=-17.2*L+388.8 (n=11, r2=0.77, p=0.0004). Catch efficiency was not estimated for Japanese sea bass > 23 mm since their abundance was quite low in the surveyed area probably due to migration to downriver or sea areas, which are considered as habitats for the following life stages
Grafting of phenylboronic acid on a glassy carbon electrode and its application as a reagentless glucose sensor
金沢大学理工研究域物質化学系Phenylboronic acid (PBA) was covalently grafted to the surface of glassy carbon (GC) electrodes using electrochemical reduction of in situ generated diazonium cation. The grafting of GC surfaces was controlled by varying both the concentration of precursor 3-aminophenylboronic acid and the number of potential cycling during the grafting procedure. Cyclic voltammetry (CV) and eletrochemical impedance spectroscopy (EIS) were used to confirm the grafting of the PBA group to the GC surface and formation of multilayer. The barrier properties of the grafted GC electrodes were studied in the presence of a redox probe such as Fe (CN)63 - / 4 - by CV. Additionally, the resultant PBA multilayer on the GC electrode was applied for glucose detection utilizing the EIS technique in the presence of a redox probe molecule. Then, the complexation ability of the grafted layers with glucose was also confirmed as an increase of total impedance at non-faradic EIS measurement. © 2010 Elsevier B.V. All rights reserved
Pathological study of pulmonary toxicity induced by intratracheally instilled Asian sand dust (Kosa): effects of lowered serum zinc level on the toxicity
Introduction. We have previously reported that Asian sand dust (ASD) induced acute and chronic inflammatory changes in the lung of mice. Zinc (Zn) is reported to influence inflammation and wound healing. The purpose of the study was to assess the effects of lowered serum Zn levels on the lung toxicity induced by ASD.
Material and methods. Mice that were fed diets containing normal (group 1) or low (group 2) content of Zn for 8 weeks were intratracheally instilled with 3.0 mg of ASD, followed by sacrifice at 24 hours, 2 weeks, and 1, 2 and 3 months after instillation. Paraffin sections of lung tissues were stained by hematoxylin and eosin and by immunohistochemistry to detect tumor necrosis factor (TNF) and interleukin (IL)-1β as well as inflammasome (NALP3), autophagy (LC-3) and lysosome (LAMP-1) markers. Selected samples of lung tissue were examined by electron microscopy.
Results. Following histological examination of the lung, similar patterns of inflammatory changes were observed in mice with normal and low serum Zn concentrations; however, they were more prominent and persistent in mice with low serum Zn level. These changes were both purulent (acute) and pyogranulomatous (chronic) in nature. In the lung lesions of group 2 mice the changes within the cytoplasmic vacuoles of enlarged ASD-containing macrophages (Mo) were clearly visible. The macrophages expressed TNF and IL-1β, and semi-quantitative analysis revealed a larger number of TNF-positive Mo in mice with normal level of serum Zn and a larger number of IL-1β-positive Mo in mice with low level of serum Zn. Decreased positive LC-3 staining and dilated lysosomes containing ASD particles were observed in the cytoplasm of Mo in mice with low serum Zn concentration.
Conclusions. These findings suggest that low serum zinc concentration may induce the modulation of cytokine expression and lysosomal malfunction by phagocytotic and/or autophagic mechanisms, and may result in interstitial pyogranulomatous inflammation in the lungs of mice treated with ASD
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