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991.
P.H. Cannington Norman S. Ham 《Journal of Electron Spectroscopy and Related Phenomena》1983,32(2):139-151
Photoelectron spectra obtained by He(I) and He(II) excitation of glycine, sarcosine and glycine methyl ester are presented. The p-type bands in the He(I) spectrum of glycine are interpreted in terms of localized molecular orbitals; the C 2s bands are identified in the He(II) spectrum. He(I) spectra of some N-acetylamino acids and of a variety of α-and ω-substituted amino acids are also reported. 相似文献
992.
Jeong Seok Oh Sayata Ghose A. I. Isayev 《Journal of Polymer Science.Polymer Physics》2003,41(22):2959-2968
The ultrasonic treatment of unfilled butadiene rubber (BR) gum with a grooved‐barrel ultrasonic reactor was carried out, leading to changes in the structure and physical properties. The ultrasonic treatment of BR gum led to gel formation, with the amount dependent on the amplitude. The rheological and mechanical properties of the ultrasonically treated samples and their vulcanizates were measured and compared with those of the virgin samples. Gel permeation chromatography measurements of the sol part of the virgin and the treated samples were carried out. Rheological property and molecular weight measurements indicated the creation of a branched structure and the occurrence of degradation in ultrasonically treated BR gum. Because of degradation, the tensile strength and Young's modulus of treated BR were lower than those of untreated BR, whereas the elongation at break was practically intact. Differential scanning calorimetry (DSC) curves at a high‐temperature range showed exothermic peaks with enthalpy reduction in the treated BR, indicating a decrease in the number of double bonds due to gel formation. DSC curves at a low‐temperature range indicated increased crystallinity in the treated samples. Competing reactions of gel formation, branching, and degradation occurred during the ultrasonic treatment. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2959–2968, 2003 相似文献
993.
994.
Corrigendum: Tetrazole Photoclick Chemistry: Reinvestigating Its Suitability as a Bioorthogonal Reaction and Potential Applications 下载免费PDF全文
995.
Synthesis of Monodisperse Bi‐Compartmentalized Amphiphilic Janus Microparticles for Tailored Assembly at the Oil–Water Interface 下载免费PDF全文
Jeong Won Kim Jangwoo Cho Jaehong Cho Prof. Bum Jun Park Yong‐Jin Kim Kyung‐Ho Choi Prof. Jin Woong Kim 《Angewandte Chemie (International ed. in English)》2016,55(14):4509-4513
Janus particles endowed with controlled anisotropies represent promising building blocks and assembly materials because of their asymmetric functionalities. Herein, we show that using the seeded monomer swelling and polymerization technique allows us to obtain bi‐compartmentalized Janus microparticles that are generated depending on the phase miscibility of the poly (alkyl acrylate) chains against the polystyrene seed, thus minimizing the interfacial free energy. When tetradecyl acrylate is used, complete compartmentalization into two distinct bulbs can be achieved, while tuning the relative dimension ratio of compartmented bulb against the whole particle. Finally, we have demonstrated that selectively patching the silica nanoparticles onto one of the bulb surfaces gives amphiphilicity to the particles that can assemble at the oil–water interface with a designated level of adhesion, thus leading to development of a highly stable Pickering emulsion system. 相似文献
996.
Eun Joo Jung Ky Hyun Chung Dong-Won Bae Choong Won Kim 《Experimental & molecular medicine》2016,48(5):e235
Nerve growth factor (NGF) is known to regulate both cancer cell survival and death signaling, depending on the cellular circumstances, in various cell types. In this study, we showed that NGF strongly upregulated the protein level of tropomyosin-related kinase A (TrkA) in TrkA-inducible SK-N-MC cancer cells, resulting in increases in various TrkA-dependent cellular processes, including the phosphorylation of c-Jun N-terminal kinase (JNK) and caspase-8 cleavage. In addition, NGF enhanced TrkA-induced morphological changes and cell death, and this effect was significantly suppressed by the JNK inhibitor SP600125, but not by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. To investigate novel targets associated with the enhancement of TrkA-induced SK-N-MC cell death caused by NGF, we performed Coomassie Brilliant Blue staining and two-dimensional (2D) proteomic analysis in TrkA-inducible SK-N-MC cells. We identified 31 protein spots that were either greatly upregulated or downregulated by TrkA during NGF treatment using matrix-associated laser desorption/ionization time of flight/time of flight mass spectrometry, and we analyzed the effects of SP600125 and wortmannin on the spots. Interestingly, 11 protein spots, including heterogeneous nuclear ribonucleoprotein K (hnRNP K), lamin B1 and TAR DNA-binding protein (TDP43), were significantly influenced by SP600125, but not by wortmannin. Moreover, the NGF/TrkA-dependent inhibition of cell viability was significantly enhanced by knockdown of hnRNP K using small interfering RNA, demonstrating that hnRNP K is a novel target associated with the regulation of TrkA-dependent SK-N-MC cancer cell death enhanced by NGF. 相似文献
997.
In this paper we consider the quadratic modification of the Heisenberg algebra and its classical limit version which we call the β-deformed Poisson bracket for corresponding classical variables. We use the β-deformed Poisson bracket to discuss some physical problems in the β-deformed classical dynamics. Finally, we consider the (α,β)- deformed classical dynamics in which minimal length uncertainty principle is given by \( [ \hat {x} , \hat {p}] = i \hbar (1 + \alpha \hat {x}^{2} + \beta \hat {p}^{2} ) \). For two small parameters α,β, we discuss the free fall of particle and a composite system in a uniform gravitational field. 相似文献
998.
Park EJ Ji HY Kim NJ Song WY Kim YH Kim YC Sohn DH Lee HS 《Biomedical chromatography : BMC》2008,22(5):548-555
A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the simultaneous determination of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone, the active components of Salvia miltiorrhiza in rat plasma, was developed. After liquid-liquid extraction with tariquidar as an internal standard, tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone were eluted from an Atlantis dC18 column within 5 min with a mixture of methanol and ammonium formate (10 mm, pH 6.5; 85:15, v/v). The analytes were detected by an electrospray ionization tandem mass spectrometry in the selected reaction monitoring (SRM) mode. The standard curves were linear (r=0.999) over the concentration range of 0.25-80 ng/mL for tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone in rat plasma. The coefficients of variation and the relative errors of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone for intra- and inter-assay at four quality control (QC) concentrations were 1.1-5.1% and -4.0-6.0%, respectively. The lower limit of quantification for tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone was 0.25 ng/mL from 100 microL of plasma. This method was successfully applied to the pharmacokinetic study of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone after oral administration of PF2401-SF, the standardized fraction of Salvia miltiorrhiza enriched with tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone to male Sprague-Dawley rats. 相似文献
999.
Soyoung Kwon Kyoungwon Lee Hwayong Kim Youn-Woo Lee Won Bae 《Colloid and polymer science》2008,286(10):1181-1191
The free radical copolymerization of N-vinyl-2-pyrrolidone and 2-methylene-1,3-dioxepane was carried out in supercritical carbon dioxide (scCO2) using three kinds of dispersants and 2,2′-azobisisobutyronitrile as the initiator. Polymerization was performed with fluorinated
polymeric dispersants synthesized in scCO2 using the solution polymerization method and commercially available siloxane-based surfactant. Spherical biocompatible and
biodegradable polymeric particles were prepared within the sub-micron size range. The effect of various ratios of the comonomer,
reaction temperature, and concentration of initiator, in addition to the types and concentrations of the dispersants, on the
particle size and morphology was investigated. The particle size and particle size distribution of copolymer particles were
controlled using the above mentioned experimental parameters. Glass transition temperatures of copolymers were varied according
to the comonomer ratios used. 相似文献
1000.
Yeong-Soon Gal Sung-Ho Jin Won-Chul Lee Jong-Wook Park Kwon Taek Lim Won Seok Lyoo Sang Youl Kim 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2008,82(9):1447-1450
The electrooptical and electrochemical properties of a self-dopable ionic conjugated polyacetylene, poly(2-ethynylpyridinium-N-benzoylsulfonate)
(PEPBS), were studied. The photoluminescence spectra of the polymer showed that the photoluminescence peak was located at
545 nm corresponding to the photon energy of 2.27 eV. The cyclic voltammograms of the polymer exhibited reversible electrochemical
behaviors between the doped and undoped peaks. It was found from the dependence of the oxidation current density of the polymer
on scan rate that the kinetics of the redox process was diffusion-controlled. The electrical conductivity (σ) of undoped PEPBS
was 5.7 × 10−9 S/cm.
The text was submitted by the authors in English. 相似文献