Development of a web-based CT dose calculator: WAZA-ARI

A web-based computed tomography (CT) dose calculation system (WAZA-ARI) is being developed based on the modern techniques for the radiation transport simulation and for software implementation. Dose coefficients were calculated in a voxel-type Japanese adult male phantom (JM phantom), using the Particle and Heavy Ion Transport code System. In the Monte Carlo simulation, the phantom was irradiated with a 5-mm-thick, fan-shaped photon beam rotating in a plane normal to the body axis. The dose coefficients were integrated into the system, which runs as Java servlets within Apache Tomcat. Output of WAZA-ARI for GE LightSpeed 16 was compared with the dose values calculated similarly using MIRD and ICRP Adult Male phantoms. There are some differences due to the phantom configuration, demonstrating the significance of the dose calculation with appropriate phantoms. While the dose coefficients are currently available only for limited CT scanner models and scanning options, WAZA-ARI will be a useful tool in clinical practice when development is finalised.     

Pore development in carbonized hemoglobin by concurrently generated MgO template for activity enhancement as fuel cell cathode catalyst

Various carbon materials with a characteristic morphology and pore structure have been produced using template methods in which a carbon-template composite is once formed and the characteristic features derived from the template are generated after the template removal. In this study, hemoglobin, which is a natural compound that could be abundantly and inexpensively obtained, was used as the carbon material source to produce a carbonaceous noble-metal-free fuel cell cathode catalyst. Magnesium oxide was used as the template concurrently generated with the hemoglobin carbonization from magnesium acetate mixed with hemoglobin as the starting material mixture to enable pore development for improving the activity of the carbonized hemoglobin for the cathodic oxygen reduction. After removal of the MgO template, the substantially developed pores were generated in the carbonized hemoglobin with an amorphous structure observed by total-electron-yield X-ray absorption. The extended X-ray absorption fine structure at the Fe-K edge indicated that Fe was coordinated with four nitrogen atoms (Fe-N(4) moiety) in the carbonized hemoglobin. The oxygen reduction activity of the carbonized hemoglobin evaluated using rotating disk electrodes was dependent on the pore structure. The highly developed pores led to an improved activity.     

Origin of Surface Coating Effect for MgO on LiCoO2 to Improve the Interfacial Reaction between Electrode and Electrolyte

Surface coating on lithium‐ion battery cathodes improves their durability at high potentials, which is a well‐known practical application. However, the mechanism is still unclear because the coating influences the electrode/electrolyte interface at a few nanometer‐scale and direct observation of the interface under real operating conditions of a battery is challenging. This study reveals the mechanism of the surface coating effect on lithium‐ion battery cathodes by using in operando X‐ray absorption spectroscopy (XAS) on well‐defined MgO‐coated LiCoO₂ thin‐film electrodes prepared via pulsed laser deposition. Total‐reflection in operando XAS measurements reveal that LiCoO₂ forms a reductive phase at the interface between the uncoated‐LiCoO₂ electrode and the electrolyte, while the MgO coating layer inhibits the redox process, leading to an improvement in the cycle performance of the battery. Depth‐resolved in operando XAS measurements indicate that a solid solution of the magnesium phase forms at the LiCoO₂ surface upon MgO coating. Magnesium ions function as pillars to stabilize the layered structure at the interface between the LiCoO₂ electrode and the electrolyte for delithiated states upon cycling at potentials.     

Production of recombinant human lysosomal acid lipase in Schizosaccharomyces pombe: development of a fed-batch fermentation and purification process

A fed-batch fermentation process has been developed to enable the production of large quantities of recombinant human lysosomal acid lipase (hLAL; EC 3.1.1.13), in Schizosaccharomyces pombe, for preclinical studies as a potential enzyme therapy drug. Recombinant S. pombe, clone ASP397-21, expressed enzymatically active hLAL in the secreted form. A feedback fed-batch system was used to determine the optimal feed rate of a 50% glucose solution used as the carbon source. The feed rate of the glucose solution was calculated by a computer-aided system according to the equation; F=q(sf)(VX)/S(in) (q(sf), specific substrate feed rate [gram substrate/gram dry cell weight/h]; V, volume of culture broth [l]; X, cell density [gram dry cell weight/l]; S(in), concentration of growth limiting substrate in feed solution [gram substrate/gram feed solution]). At the time of the initial consumption of glucose in the batch-phase culture, the nutrient supply was automatically initiated by means of monitoring the respiratory quotient change. The obtained profile of the feed rate was applied to the feed forward control fermentation. Finally, the cells were grown up to >50 g dry cell weight/l, and the hLAL expression level was approximately 16,000 U/l. Expressed hLAL protein was purified in a two-step process by hydrophobic interaction and anion exchange chromatographies. Purified recombinant hLAL exhibited a 90-150 kDa broad band upon SDS-PAGE with specific activity of about 300 U/mg. After endoglycosidase H treatment, the band converged to 45 kDa, equal to the calculated molecular weight, suggesting that hLAL produced in S. pombe was hyper-glycosylated. N-terminal analysis of de-glycosylated hLAL revealed that the signal sequence of hLAL was correctly processed in S. pombe.     

Neural Contributions of the Hypothalamus to Parental Behaviour

Parental behaviour is a comprehensive set of neural responses to social cues. The neural circuits that govern parental behaviour reside in several putative nuclei in the brain. Melanin concentrating hormone (MCH), a neuromodulator that integrates physiological functions, has been confirmed to be involved in parental behaviour, particularly in crouching behaviour during nursing. Abolishing MCH neurons in innate MCH knockout males promotes infanticide in virgin male mice. To understand the mechanism and function of neural networks underlying parental care and aggression against pups, it is essential to understand the basic organisation and function of the involved nuclei. This review presents newly discovered aspects of neural circuits within the hypothalamus that regulate parental behaviours.     

Elucidating the thermal degradation of carbazole-containing platinum–polyyne polymers

In this article, we present the significant influence of the substitution pattern of carbazole on the thermal stability of carbazole-containing platinum(II)–polyyne polymers. A series of the studies on the dynamic and isotherm conditions revealed a better thermal stability for the 3,6-carbazole based platinum(II)–polyyne polymer (36CbzPtP), where alkynes were located at the p-phenylene positions relative to the carbazole nitrogen atom, compared to that for the 2,7-carbazole based counter polymer (27CbzPtP), where the alkynes were located at the m-phenylene positions relative to the carbazole nitrogen atom. On the other hand, the thermogravimetry–mass spectrometry–Fourier transform infrared technique applied to the two polymers revealed the same degradation mechanism, which probably involved the thermal decomposition of triethyl phosphine moieties and which was followed by the C C scission of hexadecyl chains. The carbazole moieties eventually underwent degradation when the temperature exceeded 415 °C. Molecular modeling showed that polymer 27CbzPtP formed a linear structure, whereas polymer 36CbzPtP adopted a curved structures; this led to different packing modes of the polymer chains. This structural difference affected the efficiency of the initial degradation event of the triethyl phosphine groups. The curved structures of 36CbzPtP sterically protected the triethyl phosphine groups; this led to an increased thermal stability over that of 27CbzPtP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47639.     

Thermal and mechanical transient behaviour of steel doors installed in non‐load‐bearing partition wall assemblies during exposure to the standard fire test

In this paper, the authors present experimental results and observations of four full‐scale standard fire tests on single‐leaf steel doors and steel frames installed in 3 × 3 m non‐load‐bearing partition walls. Three full‐scale fire tests were performed on steel doors installed in lightweight partition walls constructed by using steel C‐section studs with gypsum boards fixed on both sides. Two lightweight walls incorporated Rockwool cavity insulation, while the third lightweight wall was constructed without cavity insulation. The fourth fire test involved a steel door installed in a masonry partition wall. While the steel door leaf and door frames were identical in all four full‐scale tests, only the steel door installed in the masonry wall achieved the desired fire resistance rating of 30 min. The integrity criterion for fire resistance was determined for the scenario when the door opened away from the furnace. The duration of fire resistance according to the integrity criterion was found to be 38, 25 and 19 min for the same door when installed in masonry wall, uninsulated lightweight wall and insulated lightweight wall respectively. For the thermal insulation criterion of fire resistance, the scenario of the door opening into the fire was found to be the most onerous. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.     

Reactivity with Water and Bulk Ruthenium Redox of Lithium Ruthenate in Basic Solutions

The reactivity of water with Li-rich layered Li₂RuO₃ and partial exchange of Li₂O with H₂O within the structure is studied under aqueous (electro)chemical conditions. Upon slow delithiation in water over long time periods, micron-sized Li₂RuO₃ particles structurally transform from an O3 structure to an O1 structure with a corresponding loss of 1.25 Li ions per formula unit. The O1 stacking of the honeycomb Ru layers is imaged using high-resolution high-angle annular dark-field scanning transmission electron microscopy, and the resulting structure is solved by X-ray powder diffraction and electron diffraction. In situ X-ray absorption spectroscopy suggests that reversible oxidation/reduction of bulk Ru sites is realized on potential cycling between 0.4 and 1.25 V_RHE in basic solutions. In addition to surface redox pseudocapacitance, the partially delithiated phase of Li₂RuO₃ shows high capacity, which can be attributed to bulk Ru redox in the structure. This work demonstrates that the interaction of aqueous electrolytes with Li-rich layered oxides can result in the formation of new phases with (electro)chemical properties that are distinct from the parent material. This understanding is important for the design of aqueous batteries, electrochemical capacitors, and chemically stable cathode materials for Li-ion batteries.