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991.
Spectral hole in the amplified spontaneous emission spectrum of a fiber optical parametric amplifier
The amplified spontaneous emission (ASE) spectrum of a fiber optical parametric amplifier in a gain-saturation condition is studied. We experimentally observed holes around the signal and the idler in the ASE spectrum of a deeply gain-saturated amplifier. This observation is explained by a theoretical model that includes parametric interactions among ASE components and the pump, signal, and idler beams. 相似文献
992.
Bo Zhu Yong He Naoki Asakawa Naoko Yoshie Haruo Nishida Yoshio Inoue 《Macromolecular rapid communications》2005,26(8):581-585
Summary: A new crystal morphology (δ form) of poly(3‐hydroxypropionate) (PHP) is found in cast and melt‐crystallized PHPs with low molecular weight, in which the PHP chains possibly adopt a 21 helix rather than the trans conformation found in the β or γ form. The fusion temperature‐ and the crystallization temperature‐dependent polymorphism are responsible for the dual morphologies and the unique growth kinetics of spherulites in the melt‐crystallized PHPs.
993.
Takafumi Mori Tungalag Dong Kouji Yazawa Yoshio Inoue 《Macromolecular rapid communications》2007,28(21):2095-2099
Films of an α‐cyclodextrin/poly(ε‐caprolactone) inclusion complex have been successfully prepared and show high transparency and heat resistance in comparison to the pure polymer film. The physical properties, such as transparency, mechanical properties, and thermal stability, of the α‐CD‐PCL‐IC films are found to depend on the α‐cyclodextrin‐to‐polymer stoichiometry.
994.
Transition Metal Chemistry - The coordination compound constructed for nitronyl nitroxide radical NIT-Ph-4-Br and CuII(hfac)2(H2O)2 building blocks... 相似文献
995.
An enhancement of environmental concern lately has improved the awareness of researchers in employing eco-friendly solvents for processing biopolymers. Recently, ionic liquids have been utilized to prepare biopolymer blends as they are non-volatile and recyclable. Biopolymers such as cellulose, chitin, chitosan, keratin, lignin, silk, starch, and zein are widely used for the preparation of biopolymer blends via dissolution in ionic liquids, followed by coagulation procedure. In this concise review, three types of ionic liquids based on imidazolium cations combined with different counter anions that are frequently utilized to prepare biopolymer blends are described. Moreover, three types of biopolymer blends that are prepared in ionic liquids were classified, specifically polysaccharide/polysaccharide blends, polysaccharide/polypeptide blends, and polysaccharide/bioplastic blends. The physicochemical properties of biopolymer blends prepared in different imidazolium-based ionic liquids are also concisely reviewed. This paper may assist the researchers in the polymer blend area and generate fresh ideas for future research. 相似文献
996.
Yutaka Inoue Takashi Yamazoe Shota Watanabe Isamu Murata Ikuo Kanamoto 《Journal of inclusion phenomena and macrocyclic chemistry》2014,78(1-4):457-464
In this study, investigations were performed in regard to the possibility of complexation of actarit (ACT) with β-cyclodextrin (β-CD) for improving the solubility and dissolution rate. Complexes of β-CD and ACT (ACT/β-CD molar ratio = 1/1) were prepared using the cogrinding method. Formation of an ACT/β-CD inclusion complex by cogrinding was confirmed using powder X-ray diffraction measurement. The powder X-ray diffraction of the ground mixture (ACT/β-CD = 1/1) showed a halo pattern. The diffraction pattern of the ground mixture after storage at RH 82 %, 40 °C exhibited new diffraction peaks at 2θ = 11.6º and 17.8º, and differed from those of ACT and β-CD crystals. In vitro studies showed that the solubility and dissolution rate of ACT were significantly improved by complexation with β-CD with respect to the drug alone. In 1H-NMR measurement, changes in chemical shift (1H) suggested that the drug phenyl moiety was included in the cavities of β-CD mainly by hydrophobic interaction, and that the primary hydroxy side of β-CD was tightly associated with each drug. The results show clear evidence of intermolecular interaction between β-CD and ACT. 相似文献
997.
Total Synthesis and Functional Evaluation of Fourteen Derivatives of Lysocin E: Importance of Cationic,Hydrophobic, and Aromatic Moieties for Antibacterial Activity 下载免费PDF全文
Takuya Kaji Dr. Motoki Murai Dr. Hiroaki Itoh Dr. Jyunichiro Yasukawa Dr. Hiroshi Hamamoto Prof. Dr. Kazuhisa Sekimizu Prof. Dr. Masayuki Inoue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16912-16919
Lysocin E ( 1 ) is a structurally complex 37‐membered depsipeptide comprising 12 amino‐acid residues with an N‐methylated amide and an ester linkage. Compound 1 binds to menaquinone (MK) in the bacterial membrane to exert its potent bactericidal activity. To decipher the biologically important functionalities within this unique antibiotic, we performed a comprehensive structure‐activity relationship (SAR) study by systematically changing the side‐chain structures of l ‐Thr‐1, d ‐Arg‐2, N‐Me‐d ‐Phe‐5, d ‐Arg‐7, l ‐Glu‐8, and d ‐Trp‐10. First, we achieved total synthesis of the 14 new side‐chain analogues of 1 by employing a solid‐phase strategy. We then evaluated the MK‐dependent liposomal disruption and antimicrobial activity against Staphylococcus aureus by 1 and its analogues. Correlating data between the liposome and bacteria experiments revealed that membrane lysis was mainly responsible for the antibacterial functions. Altering the cationic guanidine moiety of d ‐Arg‐2/7 to a neutral amide, and the C7‐acyl group of l ‐Thr‐1 to the C2 or C11 counterpart decreased the antimicrobial activities four‐ or eight‐fold. More drastically, chemical mutation of d ‐Trp‐10 to d ‐Ala‐10 totally abolished the bioactivities. These important findings led us to propose the biological roles of the side‐chain functionalities. 相似文献
998.
Dehydroxylation of naturally occurring oligomeric resveratrol derivatives resulted in the formation of compounds with dramatically reduced principal stable conformers. In addition, dehydroxylation allowed the determination of the absolute configurations of the original resveratrols via comparison of experimental and theoretical electronic circular dichroic spectra. Notably, the absolute configuration of pauciflorol B was identified using this novel procedure, which is the first application of dehydroxylated derivatives for the determination of the absolute configuration of naturally occurring polyphenols. 相似文献
999.
1000.
Ken-ichi OhnoHayato Suzuki Tatsuo Sawada 《Journal of magnetism and magnetic materials》2011,323(10):1389-1393
A tuned magnetic fluid damper (TMFD) is a dynamic absorber using a magnetic fluid. A characteristic of the TMFD is changing natural frequency of a magnetic fluid sloshing under a magnetic field. The magnetic fluid sloshing in a coaxial cylindrical container was analyzed theoretically under the axisymmetrical magnetic field. The theoretical results showed that a radial component of the magnetic field also changed the natural sloshing frequency. A policy of the suitable design of the TMFD was presented and the effect of the radial component of the magnetic field was verified experimentally. 相似文献