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131.
Kenji Okuyama Naoko Kawano Souichi Uehori Keiichi Noguchi Nobuhiro Okabe Yoshiichi Suzuki 《Molecular Crystals and Liquid Crystals》2013,570(1-2):193-201
Abstract Crystal structures of two antiferroelectric mesogens, TFMHPBC and MHPBC-10, were analysed by an X-ray diffraction method. In both crystals, mesogen molecules formed a herringbone structure which was essentially the same as that proposed for the antiferroelectric liquid crystal phase. Because of the crystallographic 21-symmetry along the b-axis, only the b-axis component of the dipole moment remains in a smectic layer. Since the dipole moment in the next layer has the same magnitude but the opposite direction, both crystals show no dipole moment as a whole. These structural features observed in their crystal states seem to be conserved in their antiferroelectric liquid crystal phases which are just above their crystal phases. 相似文献
132.
133.
Goto-Inoue N Manabe Y Miyatake S Ogino S Morishita A Hayasaka T Masaki N Setou M Fujii NL 《Analytical and bioanalytical chemistry》2012,403(7):1863-1871
Lipids in skeletal muscle play a fundamental role both in normal muscle metabolism and in disease states. Skeletal muscle lipid accumulation is associated with several chronic metabolic disorders, including obesity, insulin resistance, and type 2 diabetes. However, it is poorly understood whether the lipid composition of skeletal muscle changes by contraction, due to the complexity of lipid molecular species. In this study, we used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to investigate changes in skeletal muscle lipid composition induced by contraction. We successfully observed the reduction of diacylglycerol and triacylglycerol, which are generally associated with muscle contraction. Interestingly, we found the accumulation of some saturated and mono-unsaturated fatty acids and poly-unsaturated fatty acids containing phosphatidylcholine in contracted muscles. Moreover, the distributions of several types of lipid were changed by contraction. Our results show that changes in the lipid amount, lipid composition, and energy metabolic activity can be evaluated in each local spot of cells and tissues at the same time using MALDI-IMS. In conclusion, MALDI-IMS is a powerful tool for studying lipid changes associated with contractions. 相似文献
134.
Naoko Kubota Tsuyoshi Fukuo Ryuichi Akawa 《Journal of the American Society for Mass Spectrometry》1999,10(6):557-560
Self-assembly of 1,1′-ferrocenedicarboxylic acid in solution was detected by electrospray mass spectrometry (ESI-MS). The ESI mass spectra showed the acid was self-assembled as a cyclic tetramer in methanol and acetonitrile, and the tetramer was found to complex more strongly with the sodium ion than with any other alkali metal ion. The result was supported by semiempirical molecular orbital calculations, which indicate that the tetramer possesses a cyclic structure like a pseudo-crown ether, and its internal diameter is consistent with the diameter of a sodium ion. 相似文献
135.
We study the nonequilibrium steady state realized in a general stochastic system attached to multiple heat baths. Starting from the detailed fluctuation theorem, we derive concise and suggestive expressions for the corresponding stationary distribution which are correct up to the second order in thermodynamic forces. The probability of a microstate eta is proportional to exp[Phi(eta)] where Phi(eta)=-[under summation operator]kbeta_{k}E_{k}(eta) is the excess entropy change. Here, E_{k}(eta) is the difference between two kinds of conditioned path ensemble averages of excess heat transfer from the kth heat bath whose inverse temperature is beta_{k}. This result can be easily extended to steady states maintained with other sources, e.g., particle current driven by an external force. Our expression may be verified experimentally in nonequilibrium states realized, for example, in mesoscopic systems. 相似文献
136.
Susumu Hama Naoko Kirimura Aki Obara Hirokatsu Takatsu Kentaro Kogure 《Molecules (Basel, Switzerland)》2022,27(4)
Anti-rheumatoid arthritis (RA) effects of α-tocopherol (α-T) have been shown in human patients in a double-blind trial. However, the effects of α-T and its derivatives on fibroblast-like synoviocytes (FLS) during the pathogenesis of RA remain unclear. In the present study, we compared the expression levels of genes related to RA progression in FLS treated with α-T, succinic ester of α-T (TS), and phosphate ester of α-T (TP), as determined via RT-PCR. The mRNA levels of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), matrix metalloproteinase (MMP)-3, and MMP-13 were reduced by treatment with TP without cytotoxicity, while α-T and TS did not show such effects. Furthermore, intraperitoneal injection of TP ameliorated the edema of the foot and joint and improved the arthritis score in laminarin-induced RA model mice. Therefore, TP exerted anti-RA effects through by inhibiting RA-related gene expression. 相似文献
137.
138.
Rekha Goswami Shrestha Naoko Agari Koji Tsuchiya Kazutami Sakamoto Kenichi Sakai Masahiko Abe Hideki Sakai 《Colloid and polymer science》2014,292(7):1599-1609
We report a detail study on photoinduced rheological changes in nonaqueous photorheological (PR) fluids obtained with 1,2-diacyl-sn-glycero-3-phosphocholine-based reverse wormlike micelles, 1-palmitoyl-2-oleophosphatidylcholine (POPC)/cyclohexane/H2O, POPC/isooctane/H2O, and L-α-dioleophosphatidylcholine (DOPC)/isooctane/H2O systems. Initially, the mixtures form highly viscoelastic fluids of long, reverse wormlike micelles as confirmed by the rheological measurements. When photosensitive molecule, trans-CA, is added to these mixtures, they exhibit photosensitivity, and the viscoelasticity increases that decreases on UV irradiation. The nature of the substituent on the benzene ring of trans-CA influences the rheology. When hydroxycinnamic acid (HCA) (hydrophilic, ?OH group attached to the benzene ring of CA) is added to DOPC/isooctane/H2O phase, separation occurs; while with the methoxycinnamic acid (MOCA) and methylcinnamic acid (MCA) (hydrophobic groups, ?OCH3, and –CH3 attached to the benzene ring of CA respectively) led to higher viscoelasticity. The study on the effects of position of the substitution on CA reveals the viscosity enhancement is in the order of p-?>?m-?>?o-isomers. The different geometries obtained because of substitution and photoinduced trans-cis isomerisation is responsible for the different rheology as confirmed by the dynamic rheology, the UV absorption, and the 1H NMR spectrums. The 1H NMR spectra revealed a change in the solubilization site of CA with irradiation. cis-CA (high solubility in water) is solubilized in the vicinity of water (at the hydrophilic end of DOPC) as compared with trans-CA. This disrupts the 3D networks of reverse wormlike micelles, decreasing the η 0, plateau modulus, G 0, and relaxation time, τ R of solution. 相似文献
139.
Binary diffusion coefficients D12 and retention factors k for dibenzo-24-crown-8 and 15-crown-5 ethers at 308.18 and 313.20 K, and vitamin K1 at 313.20 K were measured in supercritical carbon dioxide by the chromatographic impulse response technique, and the effects of molecular shapes on the D12 values were studied. At 313.2 K and 11.0 MPa the D12 value of 15-crown-5 was higher than that predicted from the D12 correlation with molecular weight MW over the range from 32 of methanol to 1138 of trinervonin reported in our previous studies, while the D12 value of dibenzo-24-crown-8, disk shape molecule with MW = 448.5, was almost in agreement with that of vitamin K1, long chain molecule with MW = 450.7, and with those predicted from the correlation. 相似文献
140.
Oxidation of substituted toluenes with molecular oxygen in the presence of N,N',N' '-trihydroxyisocyanuric acid as a key catalyst 总被引:2,自引:0,他引:2
Hirai N Sawatari N Nakamura N Sakaguchi S Ishii Y 《The Journal of organic chemistry》2003,68(17):6587-6590
N,N',N' '-Trihydroxyisocianuric acid (THICA) was found to be a very efficient catalyst for the oxidation of alkylbenzenes with dioxygen. Thus, a variety of meta- and para-substituted toluenes bearing an electron-withdrawing substituent such as cyanotoluene, chlorotoluene, and toluic acid under O(2) (1 atm) in the presence of THICA (5 mol %) and Co(OAc)(2) (0.5 mol %) at 100 degrees C were smoothly oxidized to the corresponding benzoic acids in almost quantitative yields. The aerobic oxidation of toluene by THICA was compared with that by N-hydroxyphthalimide. p-Xylene was efficiently oxidized by THICA to telephthalic acid in high yield (over 95%) under mild conditions. 相似文献