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81.
Endo T  Sato M  Kajita H  Okuda N  Tanaka S  Hisamoto H 《Lab on a chip》2012,12(11):1995-1999
Two-dimensional photonic crystals (2D-PCs) fabricated on a cyclo-olefin polymer (COP) film using a printable photonics technology based on nano-imprint lithography (NIL) were used for label-free biosensing of insulin under wet conditions. In general, 2D-PC-based biosensing involves a complicated dry-up procedure after biosensing reactions on the 2D-PCs to obtain a high sensitivity through the large difference in refractive index. Therefore, it can be difficult to achieve simple operation involving single-step analysis. Performance of the biosensing under wet conditions would simplify the operational procedure. For label-free biosensing of insulin under wet conditions, the Fresnel reflection intensity change was used instead of the wavelength shift, which is the commonly used sensing signal. By detecting changes in refractive index caused by specific interactions between the antigen and antibody as the Fresnel reflection intensity changes, physiologically important concentrations of insulin could be detected, even under wet conditions. These results suggest that low-cost printed 2D-PCs offer great potential for single-step label-free biosensing through the introduction of a sample solution.  相似文献   
82.
Quantitative and qualitative methods based on PCR have been developed for genetically modified organisms (GMO). Interlaboratory studies were previously conducted for GMO quantitative methods; in this study, an interlaboratory study was conducted for a qualitative method for a GM soybean, Roundup Ready soy (RR soy), with primer pairs designed for the quantitative method of RR soy studied previously. Fourteen laboratories in Japan participated. Each participant extracted DNA from 1.0 g each of the soy samples containing 0, 0.05, and 0.10% of RR soy, and performed PCR with primer pairs for an internal control gene (Le1) and RR soy followed by agarose gel electrophoresis. The PCR product amplified in this PCR system for Le1 was detected from all samples. The sensitivity, specificity, and false-negative and false-positive rates of the method were obtained from the results of RR soy detection. False-negative rates at the level of 0.05 and 0.10% of the RR soy samples were 6.0 and 2.3%, respectively, revealing that the LOD of the method was somewhat below 0.10%. The current study demonstrated that the qualitative method would be practical for monitoring the labeling system of GM soy in kernel lots.  相似文献   
83.
In the presence of a catalyst system consisting of Pd(OAc)2, PCy3, and Zn(OAc)2, the reaction of alkynyl aryl ethers with bicycloalkenes, α,ß‐unsaturated esters, or heteroarenes results in the site‐selective cleavage of two C? H bonds followed by the formation of C? C bonds. In all cases, the alkynyloxy group acts as a directing group for the activation of an ortho C? H bond and as a hydrogen acceptor, thus rendering the use of additives such as an oxidant or base unnecessary.  相似文献   
84.
The syntheses of polylactides (PLAs) with branched peptide end groups containing reactive (ionic) moieties such as amino or carboxyl groups are described and were used to prepare PLA‐based microspheres (MSs) with positively or negatively charged surfaces. Branched peptides with hydroxyl end groups and four protected amino or carboxyl groups, Boc4‐K3‐OH or Bn4‐E3‐OH, were synthesized, and the hydroxyl group converted to an alkoxide and was used as the initiation site for the ring‐opening polymerization of L ‐lactide. Subsequent deprotection gave PLAs end‐capped with branched peptides having four amino or carboxyl groups, respectively (K3‐PLA and E3‐PLA). K3‐PLA and E3‐PLA were converted to K34+‐PLA and E34?‐PLA by acid or base treatment, respectively. MSs with charged surfaces were then prepared using K34+‐PLA or E34?‐PLA as a surfactant [MS(K34+‐PLA) or MS(E34?‐PLA)]. The ionic surface state of the MSs was confirmed by colloidal titration and zeta potential analysis.

SEM image of MSs: MS(K34+‐PLA).  相似文献   

85.
The covalent attachments of 5-fluorouracil (5FU) units to poly(ethylene glycol) monomethoxy ether (MeO-PEG) attached through ester, amide, and ether bonds were carried out; three types of linkages were obtained through which 5FU units were attached to MeO-PEG. For the investigation of the release of the 5FU units, the homogeneous hydrolysis was investigated in vitro in the presence and absence of enzymes. Although the rate of release of l-β-carboxyethyl-5FU or 1-β-hydroxyethyl-5FU from the compounds was fast, the release of 5FU itself was slow. In addition, the antitumor activity of these three types of MeO-PEG-bound 5FU unit was tested in vivo by preliminary screening by the National Cancer Institute or by the Japanese Foundation for Cancer Research.  相似文献   
86.
Dechlorinative coupling-dimerization reaction is studied to synthesize alkanes by using tris-triphenylphosphine ruthenium (II) in the presence of hydrogen atmosphere. Two types of halides (α-chlorodiarylmethanes 1a-d and bis(chlorophenylmethyl)-1,3-phenylene 6) are employed as substrates to form radical species and then dimerized to generate alkanes in high yields. To our knowledge, it is the first time that the formation of 1,1,2,2-tetraarylethanes and 1,2,9,10-tetraphenyl-di-m-xylylene over typical ruthenium-catalyzed dehalogenative coupling-dimerization conditions is reported.  相似文献   
87.
Benzaldehyde (PhCHO) is found to be able to initiate the radical polymerization of methyl methacrylate (MMA). The rate of polymerization is expressed by the following equation: Rp = const[PhCHO]0.5[MMA]1.5. The overall activation energy is estimated to be 56.3 kJ mole?1. The mechanism of polymerization is discussed.  相似文献   
88.
A new phase contrast microscopy technique for halo reduction is proposed. This technique is based on an apodization method combined with the Zernike phase contrast method. Although it has been a difficult theoretical problem, the proposed technique achieves halo reduction by considering angles of diffraction and phase differences. The technique utilizes an apodized phase plate consisting of a quarter wave phase shift ring with a 25% transmittance, and a pair of adjacent rings, which have 50% transmittance. This element is placed at the back focal plane of the objective. The result is startling, halo reduced images of phase objects providing enhanced inner details.  相似文献   
89.
This paper provides a formal framework within which to study cooperative behavior in the presence of incomplete information, and shows how far the known results in the static cooperative game theory can readily be applied to the proposed framework. The new concepts of Bayesian society, Bayesian strong equilibrium and Bayesian incentive compatible strong equilibrium are introduced and studied.  相似文献   
90.
pp? annihilation at rest into mesons is calculated in the quark rearrangement model in which 3 quarks and 3 antiquarks rearrange into 3 mesons and in the quark annihilation model in which one or two quark-antiquark pairs are annihilated and a quark-antiquark pair is created to form two or three mesons. The constants of the quark-meson coupling are adjusted such that the meson-nucleon interactions agree with experiment. The radial dependences of the quark-meson couplings are all assumed to be the same. This is determined by the vector-meson-quark interaction derived from the charge form factor of the proton. In the case of the decay into three mesons both rearrangement and annihilation models explain with similar reliability the branching ratio of the decay products. In the case of the decay into two-meson annihilation gives a better agreement with experiment than rearrangement.  相似文献   
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