Factors determining the reaction temperature of the solvent-free enzymatic synthesis of trehalose esters

Solvent-free synthesis encourages the design of processes and products that reduce the use and generation of hazardous chemicals. Given the importance of developing greener methodologies, we sought to determine the factors influencing the reaction temperature required for solvent-free, enzymatic synthesis of sugar esters such as trehalose (TRE) esters, using Novozyme 435 as the enzyme catalyst. The use of lauric acid (La) and ethyl laurate (LaEt) as acyl donors did not affect the activation temperature for the generation of trehalose diesters (TDEs), despite the differences in corresponding by-products (water and ethanol). However, when glucose (GLU) and La were employed as reaction substrates as a comparison, glucose monoester (GME) generation readily occurred at much lower temperatures than with the TRE esters, even without a water collection device. Moreover, when the glass transition temperature (T_g) of the sugar substrates increased, a higher reaction temperature was required. These results suggest that while the activation temperature of the reaction did not correlate with the boiling point of the by-product, it did correlate with the glass transition temperature (T_g) of the trehalose substrates. Thus, our work demonstrates the importance of the physical state of amorphous matrices in determining the optimal reaction temperature of a solvent-free sugar synthesis.

Experimental study of fast-neutron production and moderation for accelerator-based BNCT system

This work aims to study the fast-neutron production and moderation for the development of a compact accelerator-based multi-port Boron Neutron Capture Therapy (AB-mBNCT) system. An initial energy distribution and the efficiency of a test moderator assembly (TMA) for fast neutrons from a tungsten (W) target bombarded with a 53 MeV proton beam were measured using organic scintillators. The experimental results were reproduced with reasonable accuracy by simulations using the PHITS code. This paper will discuss about the experimental outcome and the related benchmark calculations by PHITS code.

Microwave oscillator using piezoelectric thin-film resonator aiming for ultraminiaturization of atomic clock

We developed a microwave oscillator and a micro electromechanical systems-based rubidium cell for the miniaturization of atomic clocks. A thin-film bulk acoustic resonator (FBAR) having a resonant frequency of the fundamental mode in the 3.5 GHz band was employed instead of a crystal resonator. It delivers a clock transition frequency of Rb atoms of 3.417 GHz without the need for a complicated frequency multiplication using a phase-locked loop. This topology considerably reduces the system scale and power consumption. For downsizing the atomic clock system toward the chip level as well as mass production, a microfabricated gas cell containing Rb and N₂ gases was also developed. These microcomponents were incorporated into an atomic clock test bench, resulting in a clock operation with a short-term frequency instability of 2.1 × 10^-11 at 1 s. To the best of our knowledge, this is the first report of a coherent population trapping clock operation using an FBAR-based microwave oscillator as well as a microfabricated gas cell.

Mechanical Strength of Synthetic Casting Tape for Application to Fracture Treatment of Farm Animals

Compressive and torsional strength of cyclindrically formed synthetic casting tape for animals (Vetcast Plus™), composed of polyurethane-impregnated glass fibres, was investigated to determine its adequate application to fracture treatment of farm animals. After the completion of curing reaction, six-layered samples of the synthetic casting tape tolerated a compressive load of 6630 N (680 kgf). The sixlayered casting tape had also a torsional strength of 64 N · m. The compressive strength increased with time after the initiation of curing reaction. The time required for practical curing (achieving more than 60% of a final strength) was only 30 min, and that for complete curing 120 min. It was demonstrated that efficacious and safe fracture treatment of farm animals could be carried out using the synthetic casting tape for animals when a layer number appropriate to the total body weight of the patient animal was employed. The information obtained in this study is thought to be very useful in clinical practice.

Mechanical strength of poly-urethane-impregnated synthetic casting tape was investigated to determine its adequate application to fracture treatment of farm animals. It was demonstrated that mechanical strength of cylindrically formed samples of the casting tape depended upon the layer number, and the six-layered sample tolerated a compressive load of 6630 N and a torsional load of 64 N · m when completely cured.

Standard Protocol for Exchange of Health-checkup Data Based on SGML: The Health-checkup Data Markup Language (HDML)

Objectives: To develop a health/medical data interchange model for efficient electronic exchange of data among health-checkup facilities.

Results: A Health-checkup Data Markup Language (HDML) was developed on the basis of the Standard Generalized Markup Language (SGML), and a feasibility study carried out, involving data exchange between two health checkup facilities. The structure of HDML is described.

Results: The transfer of numerical lab data, summary findings and health status assessment was successful.

Conclusions: HDML is an improvement to laboratory data exchange. Further work has to address the exchange of qualitative and textual data.