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391.
The theory of KM2O-Langevin equations for stochastic processes (or more generally, flows in inner product spaces) have been developed in view of applications to time series analysis (e.g., Okabe and Nakano, 1991; Okabe, 1999, 2000; Okabe and Matsuura, 2000). In Klimek et al. (2002) and Matsuura and Okabe (2001, 2003), we have investigated degenerate flows, which is important in the analysis of time series obtained from deterministic dynamical systems. As a continuation, we shall in this paper derive an efficient algorithm by which the minimum norm coefficients of KM2O-Langevin equations are explicitly obtained in degenerate cases. The obtained results have close relations to the calculations of conditional expectations such as nonlinear predictors of stochastic processes (Matsuura and Okabe, 2001). The method has also potential applications to financial mathematics. 相似文献
392.
Keiichi Fukushi Shinya Minami Motokazu Kitakata Masaya Nishijima Kuriko Yokota Sahori Takeda Shin-Ichi Wakida 《Analytical sciences》2006,22(8):1129-1133
We developed a capillary zone electrophoresis method with indirect UV detection for determination of ammonium cations and alkali and alkaline earth metal cations in jellyfish. As the background electrolyte, a mixture of N-methylbenzylamine, citrate, and 18-crown-6 was used for the complete separation of all analyte cations. The limits of detection were 0.13 - 0.34 mg l(-1) at a signal-to-noise ratio of three. The values of the relative standard deviation of peak area were 3.2 - 4.9%. The proposed method successfully determined the above analyte cations in jellyfish for approximately 4 min. 相似文献
393.
The dihydroxyisoleucine-, thiazoline- and dehydroamino acid-containing pentapeptide of the thiostrepton family of peptide antibiotics was synthesized, which featured the β-lactone opening by phenylselenylation, the vinylzinc addition to the chiral sulfinimine, the Wipf oxazoline-thiazoline conversion method and the oxidative syn-elimination of the phenylseleno group. 相似文献
394.
Copper‐Catalyzed Enantioselective Allyl–Allyl Coupling between Allylic Boronates and Phosphates with a Phenol/N‐Heterocyclic Carbene Chiral Ligand
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Yuto Yasuda Prof. Dr. Hirohisa Ohmiya Prof. Dr. Masaya Sawamura 《Angewandte Chemie (International ed. in English)》2016,55(36):10816-10820
Copper‐catalyzed enantioselective allyl–allyl coupling between allylboronates and either Z‐acyclic or cyclic allylic phosphates using a new chiral N‐heterocyclic carbene ligand, bearing a phenolic hydroxy, is reported. This reaction occurs with exceptional SN2′‐type regioselectivities and high enantioselectivities to deliver chiral 1,5‐diene derivatives with a tertiary stereogenic center at the allylic/homoallylic position. 相似文献
395.
Control of Metal Arrays Based on Heterometallics Masquerading in Heterochiral Aggregations of Chiral Clothespin‐Shaped Complexes
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Masaya Naito Ryo Inoue Masayuki Iida Yuuki Kuwajima Dr. Soichiro Kawamorita Dr. Naruyoshi Komiya Prof. Dr. Takeshi Naota 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):12927-12939
Heterometal arrays in molecular aggregations were obtained by the spontaneous and ultrasound‐induced gelation of organic liquids containing the chiral, clothespin‐shaped trans‐bis(salicylaldiminato) d8 transition‐metal complexes 1 . Heterometallic mixtures of complexes 1 a (Pd) and 1 b (Pt) underwent strict heterochiral aggregation entirely due to the organic shell structure of the clothespin shape, with no effect of the metal cores. This phenomenon provides an unprecedented means of generating highly controlled heterometallic arrangements such as alternating sequences [(+)‐Pd(?)‐Pt(+)‐Pd(?)‐Pt ??? ] as well as a variety of single metal‐enriched arrays (e.g., [(+)‐Pt(?)‐Pd(+)‐Pd(?)‐Pd(+)‐Pd(?)‐Pd ??? ] and [(+)‐Pd(?)‐Pt(+)‐Pt(?)‐Pt(+)‐Pt(?)‐Pt ??? ]) upon the introduction of an optically active masquerading unit with a different metal core in the heterochiral single‐metal sequence. The present method can be applied to form various new aggregates with optically active Pd and Pt units, to allow 1) tuning of the gelation ultrasound sensitivity based on the different hearing abilities of the metal units; 2) aggregation‐induced chirality transfer between heterometallic species; and 3) aggregation‐induced chirality enhancement. A mechanistic rationale is proposed for these molecular aggregations based on the molecular structures of the units and the morphologies of the aggregates. 相似文献
396.
Eriko Ohgitani Masaharu Shin-Ya Masaki Ichitani Makoto Kobayashi Takanobu Takihara Masaya Kawamoto Hitoshi Kinugasa Osam Mazda 《Molecules (Basel, Switzerland)》2021,26(12)
Potential effects of tea and its constituents on SARS-CoV-2 infection were assessed in vitro. Infectivity of SARS-CoV-2 was decreased to 1/100 to undetectable levels after a treatment with black tea, green tea, roasted green tea, or oolong tea for 1 min. An addition of (−) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while the same concentration of theasinensin A (TSA) and galloylated theaflavins including theaflavin 3,3′-di-O-gallate (TFDG) had more remarkable anti-viral activities. EGCG, TSA, and TFDG at 1 mM, 40 µM, and 60 µM, respectively, which are comparable to the concentrations of these compounds in tea beverages, significantly reduced infectivity of the virus, viral RNA replication in cells, and secondary virus production from the cells. EGCG, TSA, and TFDG significantly inhibited interaction between recombinant ACE2 and RBD of S protein. These results suggest potential usefulness of tea in prevention of person-to-person transmission of the novel coronavirus. 相似文献
397.
Objectives: This study was to clarify changes in physical function and quality of life (QOL) for postoperative, and to examine the influence of the amount of physical activity on these variables. Methods: This study included 29 patients who underwent gastrointestinal cancer surgery. The QOL measurement was used to the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire for preoperative and 2nd and 4th postoperative weeks. Physical function measured knee extension strength, 4 m walk time, 5 times sit-to-stand test, and 6-minute walk for preoperative and 1st and 2nd postoperative weeks. The amount of physical activity score was based on METs-hours, which is estimated from cumulative physical activity. As basic characteristics were investigated cancer stage, comorbidities and complications, and operative. Statistical analysis was repeated measures analysis of variance was performed to observe postoperative changes in physical function and QOL. Furthermore, stepwise multiple regression analysis was used to the parameters of physical function and QOL affected by the physical activity score were investigated. Results: Physical function decreased postoperatively and generally improved 2nd postoperative week. Though scores on the QOL functional scales improved, some items did not improve sufficiently. Multiple regression analysis showed that physical activity score had an effect on constipation and emotion functioning. Conclusions: Improvement in symptom scales is not sufficient in a short period of time, and they need to be followed up by increasing the amount of physical activity and promoting instantaneous exercise. 相似文献
398.
Yanfeng Wang Tianming Chen Masaya Kitamura Tadao Nakaya 《Journal of polymer science. Part A, Polymer chemistry》1996,34(3):449-460
A novel vinyl monomer 2-{(3-acrylamidopropyl)dimethyl ammonio}ethyl 2′-isopropyl phosphate (AAPI) having phosphatidylcholine analogous moiety and a series of new acrylamide monomers containing two long alkyl chains [stearyloleylacrylamide (SOAAm), distearylacrylamide (SSAAm), and n-docosyloleylacrylamide (DOAAm)] were synthesized and characterized. The polyacrylamides ( Va, Vb , and Vc ) were obtained from radical copolymerization of SOAAm, SSAAm, or DOAAm with AAPI in the presence of AIBN as an initiator. The investigations of these copolymers were carried out by x-ray analysis method, DSC, TG-DTA, and viscosity measurement, respectively. The copolymer Vb containing distearyl groups as hydrophobic side chains shows a crystalline state at room temperature, and the ordered structure disappears at high temperature. The phase transition from a crystalline state to a liquid-crystalline state was observed obviously only for copolymer Vb . In addition, the II-A isotherms and A-T isobars of these copolymers were measured and their stable LB films were also prepared. © 1996 John Wiley & Sons, Inc. 相似文献
399.
Tian-Ming Chen Yan-Feng Wang Masaya Kitamura Tadao Nakaya Ikuko Sakurai 《Journal of polymer science. Part A, Polymer chemistry》1996,34(7):1155-1164
A series of new phospholipid analogous acrylamide monomers ( 4a–e ) containing long alkyl chains as hydrophobic groups and containing phosphatidylcholine analogues as hydrophilic group were synthesized in high yields. The homopolymerizations and copolymerization ( 4b with 4e ) were carried out in the presence of a radical initiator. The structures and thermal properties of these polymers were investigated by x-ray diffraction analysis, DSC, and polarizing microscopy measurements. It has been revealed that these homopolymers ( 5b, 5c , and 5d ) which bear saturated long-hydrocarbon chains in the side chains exhibited not only orderly stacked bilayer structures at room temperature but also clear liquid crystalline behavior within a wide temperature range. The viscosity behavior of all polymers was found similar to usual polyelectrolytes in porlar solvent. The polymers obtained were also characterized by 1H-NMR, IR, and melting point, respectively. © 1996 John Wiley & Sons, Inc. 相似文献
400.
Application of partial least square on quantitative analysis of L-, D-, and DL-tartaric acid by terahertz absorption spectra 总被引:1,自引:0,他引:1
Nishikiori R Yamaguchi M Takano K Enatsu T Tani M de Silva UC Kawashita N Takagi T Morimoto S Hangyo M Kawase M 《Chemical & pharmaceutical bulletin》2008,56(3):305-307
Absorption spectra of polycrystalline L-, D-, and DL-tartaric acid have been measured by terahertz time domain spectroscopy (THz-TDS). Different absorption bands are observed for DL-tartaric acid and its enantiomers (L- and D-tartaric acid). This result shows that the THz-TDS can be used for distinguishing between DL-tartaric acid and enantiomers (L- and D-tartaric acid). Moreover, partial least square (PLS) can be found to improve the quantitation of L-tartaric acid in L- and DL-tartaric acid mixture by THz-TDS. 相似文献