An application of the 2-nitrobenzenesulfenyl method to proteomic profiling of human colorectal carcinoma: A novel approach for biomarker discovery

In the development of novel biomarkers, the proteomic approach is advantageous because using it the cancer-associated proteins can be directly identified. We previously developed a 2-nitrobenzenesulfenyl (NBS) method to improve quantitative proteome analysis. Here, we applied this method to proteomic profiling of colorectal carcinoma (CRC) to identify novel proteins with altered expression in CRC. Each pair of tumor and normal tissue specimens from 12 CRC patients was analyzed, and approximately 5000 NBS-labeled paired peaks were quantified. Peaks with altered signal intensities (>1.5-fold) and occurring frequently in the samples (>70%) were selected, and 128 proteins were identified by MS/MS analyses as differentially expressed proteins in CRC tissues. Many proteins were newly revealed to be CRC related; 30 were reported in earlier studies of CRC. Six proteins that were up-regulated in CRC (ZYX, RAN, RCN1, AHCY, LGALS1, and VIM) were further characterized and validated by Western blot and immunohistochemistry. All six were found to be CRC-localized, either in cancer cells or in stroma cells near the cancer cells. These results indicate that the proteins identified in this study are novel candidates for CRC markers, and that the NBS method is useful in proteome mining to discover novel biomarkers.     

Directed Evolution of a Cp*RhIII-Linked Biohybrid Catalyst Based on a Screening Platform with Affinity Purification

Directed evolution of Cp*Rh^III-linked nitrobindin (NB), a biohybrid catalyst, was performed based on an in vitro screening approach. A key aspect of this effort was the establishment of a high-throughput screening (HTS) platform that involves an affinity purification step employing a starch-agarose resin for a maltose binding protein (MBP) tag. The HTS platform enables efficient preparation of the purified MBP-tagged biohybrid catalysts in a 96-well format and eliminates background influence of the host E. coli cells. Three rounds of directed evolution and screening of more than 4000 clones yielded a Cp*Rh^III-linked NB(T98H/L100K/K127E) variant with a 4.9-fold enhanced activity for the cycloaddition of acetophenone oximes with alkynes. It is confirmed that this HTS platform for directed evolution provides an efficient strategy for generating highly active biohybrid catalysts incorporating a synthetic metal cofactor.     

On Markov Maintenance Problems

The applicability of Markov maintenance models is crucial. We need to fill the gap between theoretical and practical maintenance problems. A model is proposed for that purpose.     

Brominated organic contaminants in the liver and egg of the common cormorants (Phalacrocorax carbo) from Japan

The contamination profiles of brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs), biphenyls (PBBs), dibenzo-p-dioxins (PBDDs), and dibenzofurans (PBDFs) were determined in the liver and egg of common cormorants from Japan. PBDEs and PBBs were detected in all the samples; especially the former were detected at elevated levels. PBDDs/PBDFs were also detected in cormorants, albeit the concentrations were lower than those of the PBBs. The total concentration of PBDEs ranged from 330 to 2600 in the liver and from 600 to 3300 in the egg on a nanogram per gram of lipid basis. The concentration of PBBs was in the range from 3.0 to 33 (in the liver) and from 3.4 to 82 (in the egg) on a nanogram per gram of lipid basis. The 2,2',4,4',5,5'-hexabromobiphenyl (BB-153) was the most predominant PBB congener in either organ, which corresponds to a major constituent of the BFR FireMaster BP-6. Concentrations of PBDDs/ PBDFs in the liver (range from 21 to 470) were slightly higher than in the egg (range from 31 to 160) on a picogram per gram of lipid basis. The results of this study imply that common cormorants accumulate a high level of PBDEs and PBBs. Comparing the concentrations of brominated organic compounds with those of chlorinated analogues, good relevance between PBBs and coplanar PCBs (r2 = 0.746 [liver] and 0.715 [egg]) was elucidated. To our knowledge, the present study demonstrates the first report of PBDEs, PBBs, and PBDDs/PBDFs in the common cormorant from Japan.     

Reliability Analysis of 3-State Systems

This paper describes a reliability analysis of a system where its components take one of three states-good, degraded, or bad. For this 3-state system, the analogy of 2-state system is investigated. The calculation of system reliability can be reduced to that of the reliability of a corresponding 2-state system, provided that it is a generalized S-P system, with or without artificial, degraded components. Consequently, methods for evaluating the exact system reliability and useful bounds on system reliability of 2-state s-coherent system directly apply to 3-state systems. Some basic properties of system reliability with s-independent components are then presented. Further, some reliability bounds on systems with s-associated components are derived. Finally, the method is extended to multi-state systems. This state reduction can be used somewhat in analyzing models where time plays a role.     

Detailed LC-MS/MS analysis of ciguatoxins revealing distinct regional and species characteristics in fish and causative alga from the Pacific

Toxin profiles of representative ciguatera species caught at different locations of Japan were investigated in fish flesh by high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. Identification and quantification of 16 toxins were facilitated by the use of 14 reference toxins prepared by either synthesis or isolation from natural sources and the previous LC-MS data thereof. Sodium adduct ions [M + Na](+) were used as parent and product ions. Distinct regional differences were unveiled: ciguatoxin-1B type toxins were found in snappers and groupers from Okinawa, ciguatoxin-3C type toxins were found in a spotted knifejaw, Oplegnathus punctatus, from Miyazaki located 730 km north of Okinawa, and both types of toxins were found in a red snapper, Lutjanus bohar, from Minamitorishima (Marcus) Island. Twelve toxins were identified in a dinoflagellate, Gambierdiscus toxicus, collected as the primary toxin source in French Polynesia. Occurrence of M-seco-toxins in fish and oxidized toxins in the dinoflagellate was confirmed for the first time. The present LC-MS/MS method is rapid, specific, and accurate. It not only outperforms the currently employed mouse bioassays but also enables the study of the toxin dynamics during the food chain transmission.     

Anti-reflection Coating for Cryogenic Silicon and Alumina Lenses in Millimeter-Wave Bands

A dielectric lens with high refractive index is suitable for focusing cryogenic devices in millimeter-wave bands when an appropriate anti-reflection (AR) coating is applied. Two types of AR coatings for silicon and alumina were studied at the millimeter-wave (220 GHz) band: one is by direct machining of mixed epoxy for a silicon lens array, while the other is by laser machining of an antireflective subwavelength structure for a large alumina lens used in a re-imaging optics system. The millimeter-wave optical properties of silicon, alumina, aluminum nitride, and Stycast epoxies were measured with a Fourier Transform Spectrometer (FTS) at cryogenic temperatures. The measured refractive index of the AR coating with a mixture of Stycast 1266 (n = 1.68) and Stycast 2850FTJ (n = 2.2) for silicon at 30 K was 1.84. The thickness of the epoxy AR coating was precisely controlled with direct machining. Transmittance of the AR-coated silicon substrate, measured with FTS, was approximately 95 % at the center frequency of the 220 GHz band with a bandwidth of 25 % at 27 K. An antireflective subwavelength structure was designed for an alumina sample with periodic cylindrical holes. The measured 220-GHz-band transmittance was above 90 % with a bandwidth of 25 % at 25 K.     

Architecture of rod–brush block copolymers synthesized by a combination of coordination polymerization and atom transfer radical polymerization

A combination of coordination polymerization and atom transfer radical polymerization (ATRP) was applied to a novel synthesis of rod–brush block copolymers. The procedure included the following steps: (1) the monoesterification reaction of ethylene glycol with 2-bromoisobutyryl bromide (BIBB) yielded the bifunctional initiator monobromobutyryloxy ethylene glycol and (2) a trichlorocyclopentadienyl titanium (CpTiCl₃; bifunctional initiator) catalyst was prepared from a mixture of CpTiCl₃ and bifunctional initiator. The coordination polymerization of n-butyl isocyanate initiated by such a catalyst provided a well-defined macroinitiator, poly(n-butyl isocyanate)–bromine (PBIC–Br). (3) The ATRP method of 2-hydroxyethyl methacrylate initiated by PBIC–Br provided rod [poly(n-butyl isocyanate) (PBIC)]–coil [poly(2-hydroxyethyl methacrylate) (PHEMA)] block copolymers with a CuCl/CuCl₂/2,2′-bipyridyl catalyst. (4) The esterfication of PBIC-block-PHEMA with BIBB yielded a block-type macroinitiator, and (5) ATRP of methyl methacrylate with a block-type macroinitiator provided rod–brush block copolymers. We found from the solution properties that such rod–brush block copolymers formed nanostructured macromolecules in solution. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Contact of a spherical particle with a droplet

The collection of particles by liquid drops is profoundly influenced by the contact angle of the particles with the drops and the surface tension of the drops. The present investigation was undertaken to establish an equation with reference to the force which acts on a particle by surface tension after contact of a particle with a drop, and to simplify its solution. Moreover, the approximate equations obtained can be applied as regards the arbitrary contact angle of a particle with a drop and the arbitrary ratio of the radius of the drop to the particle. The agreement between theoretical and experimental values could be verified by this experiment.It is considered from these results that the approximate equations can be utilized when it is necessary to know the behaviour of a particle after contact with a liquid drop.