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1.
Muliadi Ramli Nasrullah Idris Kenichi Fukumoto Hideaki Niki Fujio Sakan Tadashi Maruyama Koo Hendrik Kurniawan Tjung Jie Lie Kiichiro Kagawa 《Spectrochimica Acta Part B: Atomic Spectroscopy》2007,62(12):1379-1389
A TEA CO2 laser (350 mJ–1.5 J, 10.6 μm, 200 ns, 10 Hz) was focused onto a metal sub-target under He as host gas at 1 atmospheric pressure with a small amount of impurity gas, such as water and ethanol vapors. It was found that the TEA CO2 laser with the help of the metal sub-target is favorable for generating a strong, large volume helium gas breakdown plasma at 1 atmospheric pressure, in which the helium metastable-excited state was then produced overwhelmingly. While the metal sub-target itself was never ablated. The helium metastable-excited state produced after the strong helium gas breakdown plasma was considered to play an important role in exciting the atoms. This was confirmed by the specific characteristics of the detected H emission, namely the strong intensity with low background, narrow spectral width, and the long lifetime. This technique can be used for gas and solid samples analysis. For nonmetal solid analysis, a metal mesh was introduced in front of the nonmetal sample surface to help initiation of the helium gas breakdown plasma. For metal sample, analysis can be carried out by combining the TEA CO2 laser and an Nd–YAG laser where the Nd–YAG laser is used to ablate the metal sample. The ablated atoms from the metal sample are then sent into the region of helium gas breakdown plasma induced by the TEA CO2 laser to be excited through the helium metastable-excited state. This technique can be extended to the analysis of other elements, not limited only to hydrogen, such as halogens. 相似文献
2.
Matinrad Niki Reuter-Oppermann Melanie 《Central European Journal of Operations Research》2022,30(1):251-302
Central European Journal of Operations Research - Emergency services worldwide face increasing cost pressure that potentially limits their existing resources. In many countries, emergency services... 相似文献
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Saito TK Takahashi M Muguruma H Niki E Mabuchi K 《Journal of photochemistry and photobiology. B, Biology》2001,61(3):114-121
We report a new aspect of rapid (<30 s) light-induced cell membrane damage photosensitized by 5,5"-bis(aminomethyl)-2,2':5',2"-terthiophene dihydrochloride (BAT), which is a water-soluble alpha-terthienyl analogue, using a high-power laser (light intensity 1.6 W cm(-2)). In this paper, we will discuss the relationship between the exposure time of the cells to the photosensitizer and the phototoxic process. Three toxic processes can be identified: first, a non-light-mediated toxicity dependent on BAT-cell incubation; second, a phototoxicity independent of BAT exposure time when the BAT concentration is in the 2-10-microM range; third, a phototoxicity dependent on BAT exposure time when BAT concentration becomes 20 microM. The cytotoxicity decreases when alpha-tocopherol, an antioxidant, is added to a cell membrane. This pattern of phototoxicity is the typical of a phospholipid peroxidation chain reaction and oxidative damage of membrane proteins triggered by a reactive oxygen species generated by a triplet state of BAT. The BAT exposure time is clearly correlated with the partition of the photosensitizer in the cell membrane and inside the cell. 相似文献
5.
Viola L. Borova Niki C. Maragou Pablo Gago-Ferrero Constantinos Pistos Νikolaos S. Τhomaidis 《Analytical and bioanalytical chemistry》2014,406(17):4273-4285
The present work describes the development and validation of a highly sensitive analytical method for the simultaneous determination of 68 compounds, including illicit drugs (opiates, opioids, cocaine compounds, amphetamines, and hallucinogens), psychiatric drugs (benzodiazepines, barbiturates, anesthetics, antiepileptics, antipsychotics, antidepressants, and sympathomimetics), and selected human metabolites in influent and effluent wastewater (IWW and EWW) by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). The method involves a pre-concentration and cleanup step, carried out by solid-phase extraction (SPE) using the adsorbent Strata-XC, followed by the instrumental analysis performed by LC–MS/MS, using a Kinetex pentafluorophenyl (PFP) reversed-phase fused-core column and electrospray ionization (ESI) in both positive and negative modes. A systematic optimization of mobile phases was performed to cope with the wide range of physicochemical properties of the analytes. The PFP column was also compared with two reversed-phase columns: fused-core C18 and XB-C18 (with a cross-butyl C18 ligand). SPE optimization and critical aspects associated with the trace level determination of the target compounds (e.g., matrix effects) have been also considered and discussed. Fragmentation patterns for all the classes were proposed. The validated method provides absolute recoveries between 75 and 120 % for most compounds in IWW and EWW. Low method limits of detection were achieved (between 0.04 and 10.0 ng/L for 87 % of the compounds), allowing a reliable and accurate quantification of the analytes at trace level. The method was successfully applied to the analysis of these compounds in five wastewater treatment plants in Santorini, a touristic island of the Aegean Sea, Greece. Thirty-two out of 68 compounds were detected in all IWW samples in the range between 0.6 ng/L (for nordiazepam) and 6,822 ng/L (for carbamazepine) and 22 out of 68 in all EWW samples, with values between 0.4 ng/L (for 9-OH risperidone) and 2,200 ng/L (for carbamazepine). The novel methodology described herein maximizes the information on the environmental analysis of these substances and also provides a first profile of 68 drugs in a Greek touristic area. 相似文献
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Yasuhiro Sanada Tatsuo Akiyama Yusuke Ujihira Eiji Niki 《Fresenius' Journal of Analytical Chemistry》1982,312(6):526-529
Summary Sodium ion-selective electrodes (Na+-ISE) were prepared by implanting Si+ and Li+ into alumina wafers and their characteristics were investigated. The alumina wafer had a thickness of 100 m and a diameter of 1.40 cm. The ionselective membrane was produced by ion-implanting of Li+ and Si+ on both sides of a single-crystal alumina wafer. The total doses of Li+ and Si+ were controlled to be the same, viz. 1013–1015 ions/cm2. The ion-implanted alumina wafer with 1014 or 4×1014 ions/cm2 of Li+ and Si+ showed better characteristics than the others.The response curves of the 1014 ions/cm2 implanted alumina wafer had a slope of 42 mV/pNa in a concentration range from 1–10–4mol/l. The full response achieved after about 1 min was reproducible. The proposed idea of producing Na+-ISE by ion-implantation technique was applied to functuate the gate surface of the field effect transitor to sodium ion. The sodium ion-sensitive FET (Na+-ISFET) prepared by implanting Li+ and Al+ at a dose of 5×1014 ions/cm2 showed a slope of 30 mV/pNa in a concentration range from 1–10–4mol/l.
Herstellung Na+-ionenselektiver Elektroden durch Einbau von Lithium und Silicium in Einkristall-Alumniumoxidblättchen und Anwendung zur Erzeugung von ISFET
Zusammenfassung Na+-selektive Elektroden wurden durch Einbau von Si+ und Li+ in Aluminiumoxidblättchen hergestellt und ihre Charakteristiken untersucht. Die Blättchen hatten eine Dicke von 100 m und einen Durchmesser von 1,40 cm. Ebenso wurde die Membran für einen ISFET hergestellt. Die Gesamtmenge von Li+ und Si+ wurde auf 1013–1015 Ionen/cm2 eingestellt, wobei sich bei 1014 oder 4×1014 Ionen/cm2 die beste Charakteristik ergab.Die Responsekurven der mit 1014 Ionen/cm2 versehenen Aluminiumoxidplättchen hatten eine Neigung von 42 mV/pNa in einem Konzentrationsbereich von 1–10–4mol/l. Der nach 1 min erhaltene volle Response war reproduzierbar. Die vorgeschlagene Technik wurde zur Einstellung der Gate-Oberfläche des Feldeffekt-Transistors auf Natriumion benutzt. Der Na+-sensitive FET (Na+-ISFET), der durch Einbau von Li+ und Al+ mit 5×1014 Ionen/cm2 hergestellt wurde, zeigte eine Neigung der Signalkurve von 30 mV/pNa in einem Bereich von 1–10–4mol/l.相似文献
9.
In the present paper we classify the conformally flat contact metric
manifolds of dimension
satisfying
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We prove that these manifolds are Sasakian of constant curvature 1. 相似文献
10.
The toxic properties of arsenic are well known. Honey has been widely used for monitoring this element. The present work reports a novel method for the determination of arsenic in honey, bees, pollen, and propolis, based on the coupling of microwave digestion and hydride generation. Method development included the quantitative reduction of arsenic(V) to arsenic(III), the acid used for dilution, and the complete removal of the gases following digestion. The method performance was satisfactory with recoveries between 83% and 111% and corresponding relative standard deviations between 3.1% and 24%. Among the 32 samples of honey, propolis, pollen, and honey bees analyzed, arsenic was detected in four out of six propolis samples at the method limit of detection (0.4?µg?g?1). The results indicate that propolis may be an efficient indicator for arsenic. 相似文献