Small Bend Structures Using Trenches Filled With Low-Refractive Index Material for Miniaturizing Silica Planar Lightwave Circuits

We have proposed the fabrication of small bend structures using trenches along both sides of the core, filled with low-refractive index material, in order to miniaturise silica planar lightwave circuits. The minimum bending radius of a silica waveguide was reduced from 2 mm to 200 mum by filling the trenches with low-refractive index material. The local lateral relative refractive index difference (Delta) was increased to 8.64%. We fabricated cascade S-shaped waveguides to estimate a bend loss of the proposed structure. Moreover, we applied those structures to arrayed-waveguide gratings (AWG)s. Both 8-channel, 100-GHz channel-spacing and 8-channel, 12.5-GHz channel-spacing AWGs were successfully fabricated. Compared with conventional AWGs, sizes of these devices were reduced by factors of about 2 and 4, respectively.     

Preparation of LaRuO3 films by microwave plasma-enhanced chemical vapor deposition

LaRuO₃ films were prepared by microwave plasma-enhanced chemical vapor deposition, and the effects of La/Ru supply ratio (R_La/Ru) and microwave power (P_M) on phase and microstructure were investigated. Amorphous films of carbonate or hydroxide of La were formed without microwave irradiation. At R_La/Ru < 1.0, RuO₂ films were obtained independent of P_M. At R_La/Ru = 1.6-3.2 and P_M = 0.6-1.2 kW (deposition temperatures of 973-998 K), LaRuO₃ single phase films were prepared. A product mixture of La₂RuO₅ and β-La₃RuO₇ was obtained at R_La/Ru = 4 and P_M = 1.2 kW, while a mixture of RuO₂ and La_4.87Ru₂O₁₂ was formed at R_La/Ru = 4.6 and P_M = 0.6 kW. LaRuO₃ single phase films showed metallic conduction with a high electrical conductivity of 1.6 × 10⁴ S m^− 1 at room temperature.     

Preparation of core–shell poly(l-lactic) acid-nanocrystalline apatite hollow microspheres for bone repairing applications

In this paper, hybrid inorganic–organic core–shell hollow microspheres, made of poly(l-lactic acid) (PLLA) and biomimetic nano apatites (HA), were prepared from biodegradable and biocompatible substances, suitable for bone tissue applications. Preparation is started from Pickering emulsification, i.e., solid particle-stabilized emulsions in the absence of any molecular surfactant, where solid particles adsorbed to an oil–water interface. Stable oil-in-water emulsions were produced using biomimetic 20?nm sized HA nanocrystals as particulate emulsifier and a dichloromethane (CH₂Cl₂) solution of PLLA as oil phase. Hybrid hollow PLLA microspheres at three different HA nanocrystals surface coverage, ranging from 10 to 50?μm, were produced. The resulting materials were completely characterized with spectroscopic, calorimetric and microscopic techniques and the cytocompatibility was established by indirect contact tests with both fibroblasts and osteoblasts and direct contact with these latter. They displayed a high level of cytocompatibility and thus represent promising materials for drug delivery systems, cell carriers and scaffolds for regeneration of bone useful in the treatment of orthopaedic, maxillofacial and dental fields.     

An alkyl spacer effect on the structure of 4-fluorobenzenethiol and 4-fluorobenzenemethanethiol self-assembled monolayers on Au(111)

Self-assembled monolayers (SAMs) formed by the adsorption of 4-fluorobenzenethiol (4-FBT) and 4-fluorobenzenemethanethiol (4-FBMT) on Au(111) were examined by scanning tunneling microscopy (STM) to understand the effect of a flexible methylene spacer between the sulfur head-group and phenyl group and the effect of solution temperature on the formation and structure of the SAMs. Although the adsorption of 4-FBT on Au(111) at room temperature for 24 h generated only disordered phase SAMs containing gold adatom islands, 4-FBT at 75 degrees C for 2 h formed mixed SAMs: disordered phases and ordered (2 x 12√(2))R10 degrees superlattice with a rectangular unit cell containing six adsorbed molecules. On the other hand, SAMs formed from 4-FBMT, with a methylene spacer, at room temperature for 24 h on Au(111) had irregularly ordered phases containing uniformly distributed VIs with lateral dimensions of 2-5 nm; SAMs formed from 4-FBMT at 75 degrees C for 2 h were composed of slightly improved ordered phases and larger VIs with lateral dimensions of 5-12 nm as a result of Ostwald ripening. From this study, we found that the methylene spacer plays an important role in controlling the structure of SAMs formed from p-substituted fluorinated aromatic thiols.     

Experimental study on geometric structure of isolated mixing region in impeller agitated vessel

Isolated mixing region in agitated vessel with rotated two-bladed paddle impeller and no baffle was visualized experimentally and its structural property was investigated in detail. A set of thin filaments spirally wrapping around the core of the toroidal isolated mixing region is observed under low Reynolds number conditions, which is smaller than 60. Three-dimensional geometrical structure of filament in isolated mixing region depends on the periodical perturbations caused by the rotating impeller. We have succeeded in the determination of three-dimensional geometrical structure of filament in isolated mixing region based on relation between the movement of fluid particle and filament numbers and/or wire turns. Interestingly, the wire turns of filaments are opposite to movements of fluid particles.     

Deciphering Pactamycin Biosynthesis and Engineered Production of New Pactamycin Analogues

Pactamycin is an aminocyclopentitol‐derived natural product that has potent antibacterial and antitumor activities. Sequence analysis of an 86 kb continuous region of the chromosome from Streptomyces pactum ATCC 27456 revealed a gene cluster involved in the biosynthesis of pactamycin. Gene inactivation of the Fe‐S radical SAM oxidoreductase (ptmC) and the glycosyltransferase (ptmJ), individually abrogated pactamycin biosynthesis; this confirmed the involvement of the ptm gene cluster in pactamycin biosynthesis. The polyketide synthase gene (ptmQ) was found to support 6‐methylsalicylic acid (6‐MSA) synthesis in a heterologous host, S. lividans T7. In vivo inactivation of ptmQ in S. pactum impaired pactamycin and pactamycate production but led to production of two new pactamycin analogues, de‐6‐MSA‐pactamycin and de‐6‐MSA‐pactamycate. The new compounds showed equivalent cytotoxic and antibacterial activities with the corresponding parent molecules and shed more light on the structure–activity relationship of pactamycin.     

Continuously Frequency Tunable High Power Sub-THz Radiation Source—Gyrotron FU CW VI for 600 MHz DNP-NMR Spectroscopy

A high frequency gyrotron with a 15 T superconducting magnet named Gyrotron FU CW VI has achieved continuous frequency tuning through the relatively wide range of 1.5 GHz near 400 GHz. The operation is at the fundamental cyclotron resonance of the TE₀₆ cavity mode with many higher order axial modes. The output power measured at the end of the circular waveguide system ranges from 10 to 50 watts at the low acceleration voltage of 12 kV for beam electrons. The beam current is also low. It is around 250 mA. This gyrotron is designed as a demountable radiation source for the 600 MHz DNP-NMR spectroscopy. The design and operation results of the gyrotron FU CW VI are presented.     

Construction of a novel beer proteome map and its use in beer quality control

Beer proteins were analysed by two-dimensional gel electrophoresis (2DE). The protein species associated with major spots on 2DE gels were identified by mass spectrometry followed by a database search to construct a comprehensive beer proteome map. As a result, 85 out of 199 protein spots examined were positively identified and categorised into 12 protein species. A total of 11 beer samples were brewed from the malt of eight cultivars having different levels of protein modification. This experiment was designed to demonstrate the influences of barley cultivar and malt modification on beer protein composition and beer quality characters. The beers produced from these brewing trails were subsequently analysed by 2DE and their proteomes were compared. Cultivars and malt modification affected the concentration of several proteins in beer. Beer protein concentration was associated with differences in the desirable beer quality trait, foam stability. In addition, expression of yeast derived proteins were observed that may also influence beer quality. Overall, the application of a comprehensive beer proteome map provides a strong platform for detection and potential manipulation of beer quality related proteins.     

Performance of expression vector, pTD1, in insect cell-free translation system

We constructed a pTD1 vector for an insect cell-free translation system containing a 5' untranslated region (UTR) of a polyhedrin gene as a translational enhancer sequence. Its translational efficiency was about 50-fold higher than those of mRNAs without an enhancer sequence. Moreover, the pTD1 vector functioned as an effective expression vector not only in the insect cell-free translation system but also in wheat germ extract and rabbit reticulocyte lysate systems.     

Development of a novel hydrate-based refrigeration system: A preliminary overview

This paper gives a preliminary overview of our attempt at developing a hydrate-based refrigeration system based on a novel conceptual design. The system forms a closed cycle, which is more or less analogous to the conventional vapor-compression refrigeration cycle. The cycle of present interest is performed by a multiphase refrigerant, which is typically a mixture of one or two hydrate-forming substances and water. The refrigerant is required to form a hydrate at a temperature as high as 30 °C or above, desirably under a modest pressure, such that the heat released by the exothermic hydrate formation can be efficiently removed by an environmental fluid such as the atmospheric air, groundwater or river water. The hydrate slurry thus formed is depressurized to dissociate at a lower temperature, typically 5–9 °C, thereby absorbing heat from a space to be refrigerated. To confirm the feasibility of the above conceptual design of the hydrate-based refrigeration system, a thermodynamic analysis of the system and a simulation of its operation have been performed. Also a laboratory-scale refrigerator based on the above design was constructed and tested. The paper summarizes the results of these efforts to show the potential advantages of the hydrate-based refrigeration system over conventional ones and to give the prospects of our refrigeration-system development.