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111.
Joos TO Schrenk M Höpfl P Kröger K Chowdhury U Stoll D Schörner D Dürr M Herick K Rupp S Sohn K Hämmerle H 《Electrophoresis》2000,21(13):2641-2650
In order to quantify autoantibodies in the sera of patients with autoimmune disease, we have created a microarray-based immunoassay that allows the simultaneous analysis of 18 known autoantigens. The microarrays contain serial dilutions of the various antigens, thereby allowing accurate determination of autoantibody titer using minimal amounts of serum. The assay is very sensitive and highly specific: as little as 40 fg of a known protein standard can be detected with little or no cross-reactivity to nonspecific proteins. The signal intensities observed from serial dilutions of immobilized antigen correlate well with serial dilutions of autoimmune sera. Miniaturized and highly parallelized immunoassays like these will reduce costs by decreasing reagent consumption and improve efficiency by greatly increasing the number of assays that can be performed with a single serum sample. This system will significantly facilitate and accelerate the diagnostics of autoimmune diseases and can be adapted easily to any other kind of immunoassay. 相似文献
112.
Kinetic studies on nucleophilic substitution reaction of benzyl tosylates with anilines are reported. The reaction was found to proceed via a dissociative SN2 mechanism with less than 50 % bond formation and extensive bond breaking at the transition state. It was found that positive charge development at the benzylic carbon is substantial and para-substituent effect on the substrate is predominantly of resonance type. Bond formation is shown to be favored by a better nucleophile, by an electron withdrawing group on the substrate and by the more polar(higher MeCN content) solvent. The substrate, nucleophile and solvent were found to follow the RSP. 相似文献
113.
N-Heterocyclic carbenes, prepared in situ from diarylimidazolium salts, serve as highly effective catalysts for the generation of reactive homoenolates from alpha,beta-unsaturated aldehydes. The catalyst-bound homoenolate reacts with electrophilic aldehydes leading, via the key intermediacy of an activated carboxylate, to gamma-butyrolactones in good yields and stereoselectivities. Importantly, this process demonstrates an unprecedented reaction mode for the generation of nucleophilic carbanions with a multifunctional organocatalyst under exceptionally mild and convenient reaction conditions. 相似文献
114.
9-Hydroxypheophorbide alpha-induced apoptotic death of MCF-7 breast cancer cells is mediated by c-Jun N-terminal kinase activation 总被引:1,自引:0,他引:1
Choi SE Sohn S Cho JW Shin EA Song PS Kang Y 《Journal of photochemistry and photobiology. B, Biology》2004,73(1-2):101-107
Recently, we synthesized 9-hydroxypheophorbide alpha (9-HPbD), a new chlorophyll-derived photosensitizer. The photo-treatment of MCF-7 human breast cancer cells with 20 kJ/m2 of red light after 5 microM 9-HPbD pretreatment induced cell death, showed typical apoptotic features, i.e., chromatin condensation, phosphatidyl serine externalization, membrane blebbing, and apoptotic bodies with an intact plasma membrane structure. To elucidate the mechanism of 9-HPbD-induced apoptosis, various mediators of the apoptosis were investigated. Release of cytochrome c from mitochondria into the cytosol was distinct 9 h after irradiation, while the levels of most apoptosis-related molecules such as Fas, FasL, Bcl-2, Bax and p53 were unchanged. Furthermore, caspase-9 activated by released cytochrome c was not significantly activated after 9-HPbD-photosensitization. On the other hand, stress-activated protein kinases such as p38 and c-Jun N-terminal kinase (JNK) were activated 1 h after irradiation. Blocking of JNK signaling by transfecting with the dominant negative from of the JNK gene significantly reduced 9-HPbD-induced cell death. Our data show that photosensitization with the new photosensitizer 9-HPbD could induce the apoptotic death of MCF-7 breast cancer cell and that this death is mediated by stress-activated signal through JNK. 相似文献
115.
116.
The liquid crystal (LC) alignment properties of LC cells fabricated with films of n-alkylsulphonylmethyl-substituted polyoxyethylenes (#S-PEO, #?=?4, 6, 7, 8 and 10), where # is the number of carbon atoms in the n-alkyl side groups having different n-alkyl chain length, were investigated as a function of the rubbing density. The LC cells made from unrubbed #S-PEO (# ≥8) films having more than eight carbon atoms in the n-alkyl side groups showed homeotropic LC alignment. The homeotropic LC alignment behaviour correlated well with the surface energy values of the unrubbed #S-PEO films; homeotropic LC alignment was observed when the surface energy values of the unrubbed #S-PEO films were smaller than about 21.62 mJ m?2. The LC cells made from rubbed #S-PEO (# ≥7) films having more than seven carbon atoms with a rubbing density of 150 showed homeotropic LC alignment. It was also found that the tilt angle of the LCs on the rubbed #S-PEO films was affected not only by the n-alkyl chain length of the polymers, but also by the rubbing density, regardless of the surface energy value of the #S-PEO film. 相似文献
117.
KwangSik Shin Jinhyuk Kim Kangmin Sohn Chang Joon Park SangBang Choi 《ETRI Journal》2011,33(2):219-229
In this paper, we propose a transformation scheme used to analyze online gaming traffic properties and develop a traffic model. We analyze the packet size and the inter departure time distributions of a popular first‐person shooter game (Left 4 Dead) and a massively multiplayer online role‐playing game (World of Warcraft) in order to compare them to the existing scheme. Recent online gaming traffic is erratically distributed, so it is very difficult to analyze. Therefore, our research focuses on a transformation scheme to obtain new smooth patterns from a messy dataset. It extracts relatively heavy‐weighted density data and then transforms them into a corresponding dataset domain to obtain a simplified graph. We compare the analytical model histogram, the chi‐square statistic, and the quantile‐quantile plot of the proposed scheme to an existing scheme. The results show that the proposed scheme demonstrates a good fit in all parts. The chi‐square statistic of our scheme for the Left 4 Dead packet size distribution is less than one ninth of the existing one when dealing with erratic traffic. 相似文献
118.
Christopher C. Tsai Gunny Lee Fred Raab Gregory J. Norman Timothy Sohn William G. Griswold Kevin Patrick 《Mobile Networks and Applications》2007,12(2-3):173-184
Obesity is a major public health challenge with over 65% of US adults either overweight or obese. Estimated annual costs of obesity are $78.5 billion. Self-monitoring is a critical skill for successful weight management. However, self-monitoring is labor-intensive, and compliance is often difficult. In this paper, the authors describe the Patient-Centered Assessment and Counseling Mobile Energy Balance (PmEB) mobile phone application that allows users to self-monitor caloric balance in real time. The application was developed and applied in a four-phase iterative research and development methodology. A usability study and a preliminary feasibility study were conducted. The 1 month feasibility study measured compliance and satisfaction among a sample of 15 participants randomized to one of three groups: (1) a paper diary group, (2) a PmEB group with one daily prompt, and (3) a PmEB group with three daily prompts. PmEB scored highly on usability, compliance, and satisfaction. In addition, mobile phone group users scored PmEB the same as or better than Paper Group members scored the paper diary in nearly all categories. Thematic analysis of comments revealed very positive reviews of PmEB as well as areas for improvement. PmEB is both usable and feasible for weight management self-monitoring, and the iterative pilot study methodology was effective in improving its usability. 相似文献
119.
Taegong Ryu H. Y. Sohn Young-Ugk Kim Miguel Olivas-Martinez 《Journal of nanoparticle research》2010,12(8):2851-2857
Nanosized tungsten carbide and cobalt composite powder was synthesized by a two-step reaction via a thermal plasma process. Ammonium paratungstate (APT) and cobalt oxide were used as the precursors. The injected precursors were vaporized in the plasma flame and the subsequent reduction of the vaporized precursors produced uniformly mixed nanosized tungsten and cobalt composite powder. The subsequent carburization of this powder by CH4–H2 mixture resulted in the formation of nanosized WC–Co composite powder with a particle size <110 nm. This new method represents an alternative route that avoids the post-treatment required for the WC1?x produced when methane was used for direct carburization in the powder production step. 相似文献
120.
Bruce C. Berndt Sen-Shan Huang Jaebum Sohn Seung Hwan Son 《Transactions of the American Mathematical Society》2000,352(5):2157-2177
In his first two letters to G. H. Hardy and in his notebooks, Ramanujan recorded many theorems about the Rogers-Ramanujan continued fraction. In his lost notebook, he offered several further assertions. The purpose of this paper is to provide proofs for many of the claims about the Rogers-Ramanujan and generalized Rogers-Ramanujan continued fractions found in the lost notebook. These theorems involve, among other things, modular equations, transformations, zeros, and class invariants. 相似文献