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141.
Hyperplane arrangements of rank 3 admitting an unbalanced Ziegler restriction are known to fulfill Terao's conjecture. This long-standing conjecture asks whether the freeness of an arrangement is determined by its combinatorics. In this note we prove that arrangements which admit a locally heavy flag satisfy Terao's conjecture which is a generalization of the statement above to arbitrary dimension. To this end we extend results characterizing the freeness of multiarrangements with a heavy hyperplane to those satisfying the weaker notion of a locally heavy hyperplane. As a corollary we give a new proof that irreducible arrangements with a generic hyperplane are totally nonfree. In another application we show that an irreducible multiarrangement of rank 3 with at least two locally heavy hyperplanes is not free. 相似文献
142.
143.
Nurul Asyikeen Ab Mutalib Yi Deng An-Ju Hsueh Koki Kariya Toshiaki Kurihara Hiroaki Suzuki 《Electroanalysis》2021,33(10):2123-2127
The interfacial potential difference on the surface of bipolar electrodes was controlled by placing Ag/AgCl on part of the electrode. Oxygen reduction on the cathodic pole was coupled with an electrochemiluminescence (ECL) reaction on the anodic pole. In an open bipolar system, the ECL intensity depended on the location of Ag/AgCl and the concentration of Cl− ions. A current flowed through Ag/AgCl and the ratio of currents generated at the anodic and cathodic poles was affected by the position of Ag/AgCl. Further, the effect of Ag/AgCl placement was also demonstrated in a closed bipolar system using hydrogen peroxide (H2O2) and glucose as analytes. Ag/AgCl was also effective in adjusting the sensitivity to these analytes to achieve the best performance. This method of interfacial potential control is expected to contribute toward the development of reliable sensing devices and applications such as redox cycling, which require precise potential control. 相似文献
144.
Enhanced Charge Separation Efficiency in Pyridine‐Anchored Phthalocyanine‐Sensitized Solar Cells by Linker Elongation 下载免费PDF全文
Takuro Ikeuchi Dr. Saurabh Agrawal Dr. Masayuki Ezoe Prof. Dr. Shogo Mori Prof. Dr. Mutsumi Kimura 《化学:亚洲杂志》2015,10(11):2347-2351
A series of zinc phthalocyanine sensitizers ( PcS22 – 24 ) having a pyridine anchoring group are designed and synthesized to investigate the structural dependence on performance in dye‐sensitized solar cells. The pyridine‐anchor zinc phthalocyanine sensitizer PcS23 shows 79 % incident‐photon to current‐conversion efficiency (IPCE) and 6.1 % energy conversion efficiency, which are comparable with similar phthalocyanine dyes having a carboxylic acid anchoring group. Based on DFT calculations, the high IPCE is attributed with the mixture of an excited‐state molecular orbital of the sensitizer and the orbitals of TiO2. Between pyridine and carboxylic acid anchor dyes, opposite trends are observed in the linker‐length dependence of the IPCE. The red‐absorbing PcS23 is applied for co‐sensitization with a carboxyl‐anchor organic dye D131 that has a complementary spectral response. The site‐selective adsorption of PcS23 and D131 on the TiO2 surface results in a panchromatic photocurrent response for the whole visible‐light region of sun light. 相似文献
145.
Hiroshi Harada Takuro Endo Yasunori Momose Hiroshi Kusama 《Rapid communications in mass spectrometry : RCM》2009,23(5):564-570
The detection of the reactive metabolites of drugs has recently been gaining increasing importance. In vitro trapping studies using trapping agents such as glutathione are usually conducted for the detection of reactive metabolites, especially those of cytochrome P450‐mediated metabolism. In order to detect the UDP‐glucuronosyltransferase (UGT)‐mediated bioactivation of drugs, an in vitro trapping method using N‐acetylcysteine (NAC) as a trapping agent followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed in this study. After the test compounds (diclofenac and ketoprofen) had been incubated in human liver microsomes with uridine diphosphoglucuronic acid (UDPGA) and NAC, the NAC adducts formed through their acyl glucuronides were analyzed using LC/MS/MS with electrospray ionization (ESI). The NAC adduct showed a mass shift of 145 units as compared to its parent, and the characteristic ion fragmentations reflected the parent. This is a concise and high‐throughput method for evaluating reactive metabolites by UGT‐mediated bioactivation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
146.
Takao Tsuneda Hiroki Sumitomo Masatoshi Hasebe Takuro Tsutsumi Tetsuya Taketsugu 《Journal of computational chemistry》2023,44(2):93-104
It is established that the reactive orbital energy theory (ROET) theoretically reproduces the rule-based electronic theory diagrams of organic chemistry by a comparative study on the charge transfer natures of typical organic carbon–carbon and carbon–heteroatom bond formation reactions: aldol, Mannich, α-aminooxylation, and isogyric reactions. The ROET, which is an expansion of the reaction electronic theories (e.g., the frontier orbital theory) in terms of orbital energies, elucidates the reactive orbitals driving reactions and the charge transferability indices of the reactions. Performing the ROET analyses of these reactions shows that the charge transfer directions given in the rule-based diagrams of the electronic theory are reproduced even for the functional groups of charge transfer destinations in all but only two processes for 38 reaction processes. The ROET analyses also make clear the detailed orbital-based pictures of these bond formation reactions: that is, the use of the out-of-plane antibonding π orbitals in acidic conditions (enol-mode) and in-plane antibonding π orbitals in basic conditions (enolate-mode), which explain the experimentally assumed mechanisms such as the π-bond formations in acidic conditions and σ-bond formations at α-carbons in basic conditions. Furthermore, the ROET analyses explicate that the methyl group initially accepts electrons and then donates them to the bond formations in the target reactions. It is, consequently, suggested that the ROET serves a theoretical foundation for the electronic theory of organic chemistry. 相似文献
147.
Daikoku S Ako T Kato R Ohtsuka I Kanie O 《Journal of the American Society for Mass Spectrometry》2007,18(10):1873-1879
Glycans, a family of compounds often attached to proteins and ceramides, are diverse molecules involved in a wide range of biological functions. Their structural analysis is necessary and is often carried out at the microscale level. Methods based on mass spectrometry are therefore used, although they do not provide information regarding isomeric structures often found in glycan structures. If one finds "factors" characteristic of a certain isomer, this information can be used to elucidate an unknown oligosaccharide sequence. One potential technique is to use energy-resolved mass spectrometry (ERMS) that has been used to distinguish a pair of isomeric compounds. Thus, compounds in a combinatorial library might be effectively used for this purpose. We analyzed a set of 16 isomeric disaccharides, the structures of which consisted of all possible combinations of anomeric configurations and interglycosidic linkage positions. All of the compounds were distinguished based on ERMS where normal collision-induced dissociation could distinguish only seven compounds. Furthermore, it was shown that alpha-glycosidic linkages of fucose were more reactive than the beta-isomers and the secondary glycosides were more reactive than the primary glycosides. 相似文献
148.
The majority of structural investigations of oligosaccharides based on mass spectrometry use naturally occurring oligosaccharides, which do not allow extracting any common feature associated with anomeric structures and linkage positions. In order to address the issue to find such characteristics possibly contained in oligosaccharide structure, a synthetic combinatorial trisaccharide library was analyzed. The trisaccharides used in the analysis consisted of L-fucose, D-galactose and D-glucose, in which individual glycosidic linkages existed in either alpha- or beta-anomers. The analysis of energy-resolved mass spectra (ERMS) and the scattered plot analysis of some parameters obtained from ERMS for a series of trisaccharides revealed that lower activation energy was required for the dissociation of alpha-glycosides of these sugars compared to those of the corresponding beta-anomers. It is suggested that this finding may be useful in structural analysis of natural oligosaccharides. 相似文献
149.
The present study demonstrates improvement in sensitivity and specificity of hapten assay by using antigen heterology in conjunction with low molecular weight biotin label as compared to high molecular weight horseradish peroxidase (HRP) label. For generation of antiserum, cortisol-3-O-carboxylmethyl-oxime-bovine serum albumin (F-3-CMO-BSA) was used as immunogen whereas, for the preparation of primary label, corticosterone-3-carboxymethyl oxime (B-3-CMO) was coupled with biotinylcaproylhydrazide and HRP by employing N-hydroxysuccinimide mediated carbodiimide reaction. The data of the present study revealed that the antigen heterologous assay which employed high molecular weight HRP label showed 100% cross-reaction with corticosterone. On the contrary, when HRP was replaced with low molecular weight biotin label, less than 0.1% cross-reaction was observed with all analogous C18, C19, C21 and C27 steroids including corticosterone (0.2%). Moreover, the sensitivity of the later assay was 0.09 μg/dL, which is appreciable as compared to previously reported enzyme based assays. The recovery of the exogenously spiked serum pools lies in the range of 90.3-104.2%. The intra-assay and inter-assay coefficient of variation (CVs) ranged from 3.3% to 7.8% and 2.3% to 7.7%, respectively. The serum cortisol values obtained by this method correlated well with those obtained by radioimmunoassay; r = 0.9 (n = 50). The use of much stable biotin label in place of HRP has made the antigen heterologous enzyme linked immunosorbent assay (ELISA) of cortisol assay highly specific and sensitive. 相似文献
150.
Kyotani M Matsushita S Nagai T Matsui Y Shimomura M Kaito A Akagi K 《Journal of the American Chemical Society》2008,130(33):10880-10881
In this communication, we report a novel preparation of the helical carbon nanofibril-fabricated thin film from the iodine-doped filmy helical polyacetylene through a carbonization process. Carbonization of the helical polyacetylene films by way of iodine doping is found to afford carbon and graphitic films completely preserving morphologies and even helical nanofibril structures. 相似文献