Prolongation of total permissible circulatory arrest duration by deep hypothermic intermittent circulatory arrest

Single-headed myosin was prepared by digestion of porcine aorta smooth muscle myosin with Staphylococcus aureus V8 protease in the presence of actin. The single-headed myosin preparation contained intact light chains, a rod fragment of a heavy chain, and a heavy chain of which only a minor fraction contained a nick in the head segment. Below 0.2 M NaCl, the single-headed myosin showed a decrease in Ca2+-ATPase activity and an increase in the elution time on gel filtration HPLC in a phosphorylation-dependent manner, indicating a phosphorylation-dependent conformational transition between the extended and folded forms. These conformations were confirmed by electron microscopic observation of rotary-shadowed samples of single-headed myosin. However, the conformational transition of single-headed myosin occurred in a narrower range with lower salt concentrations than that of double-headed myosin. The filament assembly of single-headed myosin was thus facilitated and phosphorylation-independent. The single-headed myosin also showed high actin-activated ATPase activity independent of phosphorylation. These results indicate that the two-headed structure of smooth muscle myosin is not essential for the conformational transition, but is required for the phosphorylation-dependent regulation of enzymatic activity and filament assembly.     

Characterization of high- and low-molecular weight zinc-dependent acid phosphatases in bovine liver

We have purified two forms of Zn2+-dependent acid phosphatase (Zn2+-APase) from bovine liver, both of which require Zn2+ to hydrolyze the substrate p-nitrophenyl phosphate in an acidic environment. The apparent molecular weights of these two forms of Zn2+-APase were estimated to be about 100,000 and 62,000 by gel filtration, and about 44,000 and 31,000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, respectively. The low-molecular weight (LMW) Zn2+-APase catalyzed the hydrolysis of myo-inositol-1-phosphate in the presence of 3 mM Mg2+ at physiological pH, but the high-molecular weight (HMW) enzyme did not. The LMW-Zn2+-APase of bovine liver was recognized by polyclonal antibodies developed against the Zn2+-APase of bovine brain, but the HMW-Zn2+-APase was not.     

侧链型液晶高分子的合成

讨论了4′甲氧基苯基—4(6″-丙烯酰氧已基)苯甲酸酯(MPAHA)和对氯甲基苯乙烯(CMS)共聚物以及CMS相应的肉桂酸酯衍生物乙烯基苯甲基肉桂酸酯(VBC)共聚物的合成。DSC和偏光显微镜分析表明:该共聚物具有热致变高分子的行为,并根据分子链中MPAHB链节含量的高低,其T_(?)和T_1值发生相应的变化。     

Topology optimization of supporting structure for seismic response reduction of an arch

A flexible supporting structure that reduces seismic response of an arch is proposed. Topology and cross-sectional areas of the supporting structure modeled as a truss structure are optimized through two steps of static and dynamic optimization problems. In the first step, a flexible supporting structure that has diagonal displacement at the top under horizontal load is obtained by solving static optimization problems. Then, in the second step, the cross-sectional area of the flexible member is optimized to minimize the seismic response acceleration of the arch evaluated by the complete quadratic combination (CQC) method. Time-history seismic response analysis is carried out to show that the response in the normal direction of the roof successfully decreases due to flexibility of the supporting structure; in addition, installing passive energy dissipation devices into the flexible supporting structure is very effective in reducing the tangential response of the arch.     

Investigation of the arrangement of oxide ion vacancies and their effect on the crystal structure of BaFe0.9In0.1O3−δ

The crystal structure of BaFe_0.9In_0.1O_3−δ, which was prepared via heating in N₂ (BFI010-N₂), was evaluated using high-temperature X-ray diffraction (XRD) and in situ convergent-beam electron diffraction (CBED) at room temperature and 700°C. Although the crystal structure of BFI010-N₂ at room temperature was assigned to a cubic perovskite-type structure based on the XRD results, the CBED patterns indicated that the space group of its crystal structure was not (No. 221), which corresponds to an ideal cubic perovskite. When the temperature was increased to 700°C, the symmetries for the space group of cubic perovskite were directly observed by means of in situ CBED, indicating that the partial ordering and/or clustering of oxide ion vacancies in the BFI010-N₂ vanished and that the oxide ion vacancy arrangements became completely random. The change in crystal symmetry agreed with a sudden decrease in the activation energy of oxide ion conduction at 600°C. The crystal symmetry of the BaFe_0.9In_0.1O_3−δ sample that was prepared via heating in O₂ (BFI010-O₂) and had a decreased δ value was compared with that of the BFI010-N₂ sample. It was concluded that the same phase transition also occurred by a decrease in δ, similar to phase transitions caused by increasing the temperature.     

Optical interconnection using VCSELs and polymeric waveguidecircuits

We investigated the waveguide loss and transmission characteristics for optical interconnection using vertical-cavity surface-emitting lasers (VCSELs) and multimode polymeric waveguide circuits with crossings. The excess loss with 100 crossings is 2.2 dB when the image magnification from a VCSEL to a waveguide is 2.3. We obtained error-free (i.e., bit error rate <10^-11) optical interconnection at 1.0625 Gbps regardless of the number of crossings or the magnification. These results suggest the practicality of large-scale optical interconnection between VCSEL-based smart-pixel chips using multimode waveguides with more than 100 crossings     

Optical MEMS for photonic switching-compact and stable optical crossconnect switches for simple, fast, and flexible wavelength applications in recent photonic networks

We review the development trends and state-of-the-art technologies of large-port-count optical switches over the past decade. Practical implementation of optical switch fabrics is discussed in terms of optical switch architectures, optical configurations, port counts, switch elements, and so on. We describe compact and stable optical crossconnect three-dimensional microelectromechanical systems (3-D-MEMS) switches that are a key technology in recent photonic networks. To show how these enable simple, fast, and flexible wavelength applications in the photonic layer, we discuss the fast and stable MEMS switching by novel comb actuator and V-shaped torsion bar, compact optical configuration with roof-type mirror, stable switch housing with cubic structure, packaging techniques by tolerance expansion and simple procedures of the component assembly, MEMS mirror controller with fast and low power digital notch circuit, reliability by shock absorption, and field trials. In addition, we discuss the impact of these switches on system integration for recent metropolitan area networks and enterprise networks.     

Development of Trityl Group Anchored Solubilizing Tags for Peptide and Protein Synthesis

Recently, solubilizing tag methods (Trt-K and Trt-R method) were developed for the challenging synthesis of peptides/proteins by means of native chemical ligation. In this system, the solubilizing tag can be attached to the Cys side chain by simply mixing the tag-introducing reagent under acidic conditions. The tagged peptides/proteins exhibited high water solubility thanks to the introduction of redundant oligo-Lys/Arg. In the final reaction, the tag can be quickly and cleanly detached by a standard deprotection reaction with trifluoroacetic acid. Herein, the development and application of these methods are described.