Oxidation of aniline to nitrobenzene by nonheme bromoperoxidase

Nonheme bromoperoxidase found in Pseudomonas putida catalyzed the bromination of aniline with hydrogen peroxide and bromide ions to give o- and p-bromoanilines. However, in the absence of bromide ions, it oxidized aniline via azobenzene and azoxybenzene finally into nitrobenzene. This is the first report of the biological oxidation of an arylamine to the corresponding nitrocompound at the enzyme level. In addition, nitrobenzene was not formed by a nonheme bromoperoxidase from Corallina pilulifera (marine alga), implying that the alga enzyme has a different reaction mechanism.     

Fontanel ultrasonography of purulent meningitis in children in Abidjan (Ivory Coast)

Reactive arthritis (ReA) is one of the most common arthritides affecting young adults. In most cases it follows urogenital or enteric bacterial infection, but its pathogenesis is not fully understood. It is generally considered a sterile arthritis which appears to involve immune response to bacterial organisms and genetic host susceptibility associated with the presence of HLA-B27 antigen. New findings suggest that in some ReA cases, viable bacteria are present inside the joints, and these organisms may cause the disease and trigger the inflammatory response. ReA manifests clinically as a rheumatoid factor negative oligoarthritis associated with enthesopathy and certain mucosal and skin lesions. Laboratory findings in ReA are non-specific. Although concepts of its pathogenesis are still evolving, so-called ReA remains an important condition to be distinguished from rheumatoid arthritis. Prognosis is generally better. Treatments with known effects in some cases include non-steroidal anti-inflammatory drugs, intra-articular corticosteroids, oral tetracyclines and sulphasalazine. The occasional chronic and severe ReA may be very difficult to treat.     

Shape dependence of resistance force exerted on an obstacle placed in a gravity‐driven granular silo flow

Resistance force exerted on an obstacle in a gravity‐driven slow granular silo flow is studied by experiments and numerical simulations. In a two‐dimensional granular silo, an obstacle is placed just above the exit. Then, steady discharge flow is made and its flow rate can be controlled by the width of exit and the position of obstacle. During the discharge of particles, flow rate and resistance force exerting on the obstacle are measured. Using the obtained data, a dimensionless number characterizing the force balance in granular flow is defined by the relation between the discharge flow rate and resistance‐force decreasing rate. The dimensionless number is independent of flow rate. Rather, we find the weak shape dependence of the dimensionless number. This tendency is a unique feature for the resistance force in granular silo flow. It characterizes the effective flow width interacting with the obstacle in granular silo flow. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3849–3856, 2018     

Multi‐primary image projector using programmable spectral light source

This paper presents a practical prototype of a multi‐primary image projector system in which light source spectra can be programmable for suiting any purpose. Our multi‐primary projection system is mainly configured with a light source component and an image projection component. The programmable light source can reproduce any spectral curve. Spatial images are then generated using a digital mirror device chip that quickly controls the intensity of the light source spectra in 2D image plane. The multi‐primary images in our projection system are reproduced by multiplexing the time‐sequential images with different primary colors. Our multi‐primary image projector realizes not only wide gamut projection but also spectral projection. To achieve this, we also show how light source spectra of four or six primary colors are designed.     

Photocatalytic Reduction of CO2 with H2O on Ti-Containing Porous Silica Thin Film Photocatalysts

Two different Ti-containing porous silica thin films having a hexagonal and cubic pore structure were synthesized and used as photocatalysts for the reduction of CO₂ with H₂O at 323 K. UV irradiation of the Ti-containing porous silica thin films in the presence of CO₂ and H₂O led to the formation of CH₄ and CH₃OH with a high quantum yield of 0.28%. These porous silica thin film photocatalysts having a hexagonal pore structure exhibited higher reactivity than the Ti-MCM-41 powder photocatalysts with the same pore structure.     

Preparation of carbon material with SiC-concentration gradient by silicon impregnation and its oxidation behaviour

A carbon material with a SiC-concentration gradient was prepared by a silicon impregnation process. In order to prepare the carbon material with a SiC-concentration gradient without any adhesion of metallic silicon, the weight of silicon powder per physical surface area of the carbon substrate was in the range of 3·9-4·1 g cm⁻² and then heating the carbon substrate in silicon powder at 1450°C for 3 h, but the amount of silicon powder beyond this range resulted in the adhesion of metallic silicon. The concentration of SiC along the thickness in the sample obtained decreased rapidly up to 0·5 mm and gradually in a range of 0·5-1·0 mm. A remarkable improvement in the oxidation resistance was observed on the sample with a SiC-concentration gradient at 1400°C, which was due to the formation of a protective film of SiO₂ glass on the surface. In the results of the thermal shock test in the sample, no destructions and no cracking of the samples were observed.     

A new shooting algorithm for the search of periodic orbits

The periodic orbit theory gives the basic framework to study a quantum and classical correspondence. In this paper, we firstly report that we have found the existence of a certain surface, which we call the devil’s staircase surface. Secondly, taking the advantage of some intriguing properties of this surface, we propose a new method to exhaustively search for periodic orbits in the anisotropic Kepler problem. Our method fully takes into account of an intriguing property of the initial value problem of the anisotropic Kepler problem, and it reduces the two-dimensional search into the one-dimensional search. Using this method, all of the periodic orbits up to the length \(2N=20\) (altogether 19284 distinct periodic orbits) have been successfully obtained, which exceeds the world record of 76 periodic orbits up to \(2N=10\) .     

Kinematic properties of human arm reaching movements in a three-dimensional space

In this study, kinematic properties of human arm reaching movements have been analyzed by use of experimental results of arm trajectories observed in a three-dimensional (3D) space. In the beginning, hand paths obtained by the experiments are kinematically analyzed to pursue their linearity, and we successfully specify a plane on which a hand moves. In the next place, the hand speed profile is calculated by use of position data observed by the experiment in a 3D space. Besides, the hand speed profile is also analytically produced under the minimum jerk criterion with respect to the displacement along the hand path. These observed and produced trajectories are compared, and the similarity of two trajectories has been demonstrated. As a result of the analyses for path and the speed profile of a hand, kinematic properties of human arm trajectories have been identified.     

Accumulable optimistic fair exchange from verifiably encrypted homomorphic signatures

Let us consider a situation where a client (Alice) frequently buys a certain kind of product from a shop (Bob) (e.g., an online music service sells individual songs at the same price, and a client buys songs multiple times in a month). In this situation, Alice and Bob would like to aggregate the total transactions and pay once per month because individual payments are troublesome. Though optimistic fair exchange (OFE) has been considered in order to swap electronic items simultaneously, known OFE protocols cannot provide such aggregate function efficiently because various costs are bounded by the number of transactions in the period. In order to run this aggregation procedure efficiently, we introduce a new kind of OFE called accumulable OFE (AOFE) that allows clients to efficiently accumulate payments in each period. In AOFE, any memory costs, computational costs, and communication complexity of the payment round must be constant in terms of the number of transactions. Since a client usually has just a low power and poor memory device, these efficiencies are desirable in practice. Currently, known approaches (e.g., based on verifiably encrypted signature scheme) are not very successful for constructing AOFE. Thus, we consider a new approach based on a new cryptographic primitive called verifiably encrypted homomorphic signature scheme (VEHS). In this paper, we propose a generic construction of AOFE from VEHS and also present a concrete VEHS scheme over a composite-order bilinear group by using the dual-form signature techniques. This VEHS scheme is also of independent interest. Since we can prove the security of VEHS without random oracles, our AOFE protocol is also secure without random oracles. Finally, we implemented our AOFE protocol, and it is efficient enough for practical use.