Energetics of three-state unfolding of a protein: canine milk lysozyme

Thermodynamics of thermal transitions of a calcium-binding lysozyme,canine milk lysozyme (CML), was studied using differential scanningcalorimetry and compared with those for homologous proteins,human     

Calorimetric study of mutant human lysozymes with partially introduced Ca2+ binding sites and its efficient refolding system from inclusion bodies

During the process of evolution, ancestral lysozymes evolved into calcium-binding lysozymes by acquiring three critical aspartate residues at positions 86, 91 and 92. To investigate the process of the acquisition of calcium-binding ability, two of the aspartates were partially introduced into human lysozyme at positions 86, 91 and 92. These mutants (HLQ86D, HLA92D and HLQ86D/D91Q/A92D), having two critical aspartates in calcium-binding sites, were expressed in Escherichia coli as non-active inclusion bodies. For the preparation of lysozyme samples, a refolding system using thioredoxin was established. This system allowed for effective refolding of wild-type and mutant lysozymes, and 100% of activity was recovered within 4 days. The calcium ion dependence of the melting temperature (Tm) of wild-type and mutant lysozymes was investigated by differential scanning calorimetry at pH 4.5. The Tm values of wild-type, HLQ86D and HLA92D mutants were not dependent on calcium ion concentration. However, the Tm of HLQ86D/D91Q/A92D was 4 degrees higher in the presence of 50 mM CaCl2 than in its absence, and the calcium-binding constant of this mutant was estimated to be 2.25(+/-0.25)x10(2) M(-1) at pH 4.5. Moreover, the calcium-binding ability of this mutant was confirmed by the result using Sephadex G-25 gel chromatography. These results indicate that it is indispensable to have at least two aspartates at positions 86 and 92 for acquisition of calcium-binding ability. The process of the acquisition of calcium-binding site during evolution of calcium-binding lysozyme is discussed.      

Phenolic rigid organic filler/isotactic polypropylene composites. II. Tensile properties

A novel phenolic rigid organic filler (KT) was used to modify isotactic polypropylene (iPP). The influence of KT particles on the tensile properties of PP/KT microcomposites was studied by uniaxial tensile test and the morphological structures of the stretched specimens were observed by scanning electron microscopy (SEM) and polarized optical microscopy (POM). We found that the Young’s modulus of PP/KT specimens increased with filler content, while the yield and break of the specimens are related to the filler particles size. The yield stress, the breaking stress and the ultimate elongation of PP/KT specimens were close to those of unfilled iPP specimens when the maximal filler particles size is less than a critical value, which is 7 μm at a crosshead speed of 10 mm/min and 3 μm at 200 mm/min, close to that of glass bead but far more than those of other rigid inorganic filler particles. The interfacial interaction was further estimated from yield stress, indicating that KT particles have a moderate interfacial interaction with iPP matrix. Thus, the incorporation of small KT particles can reinforce iPP matrix and simultaneously cause few detrimental effects on the other excellent tensile properties of iPP matrix, due to their organic nature, higher specific area, solid true-spherical shape and the homogenous dispersion of the ROF particles in microcomposites.     

Carrier transport properties in highly ordered smectic liquid crystal phase

We have designed and synthesized a new liquid crystalline phenylbenzothienobenzothiphene derivative, Ph‐BTBT‐4S‐3, in order to investigate the carrier transport properties in highly ordered smectic liquid crystal phase at a wide temperature range lower than room temperature enough to analyze them. Ph‐BTBT‐4S‐3 exhibits smectic E (SmE) phase, which is the one of highly ordered smectic liquid crystal phases, at the wide temperature range from 200°C to under ?130°C. Thanks to its wide temperature range of SmE phase, we could reveal the carrier transport properties in the low temperature range, which were well explained on the basis of Gaussian disorder model having a Gaussian width, σ, of 87 meV, which was larger than those of typical nonpolar liquid crystals of 40?60 meV and was attributed to additional dipole of a thioether group in the side chain.     

Vortex Molecules in Bose-Einstein Condensates

Stable vortex dimers are known to exist in coherently coupled two component Bose-Einstein condensates (BECs). We construct stable vortex trimers in three component BECs and find that the shape can be controlled by changing the internal coherent (Rabi) couplings. Stable vortex N-omers are also constructed in coherently coupled N-component BECs. We classify all possible N-omers in terms of the mathematical graph theory. Next, we study effects of the Rabi coupling in vortex lattices in two-component BECs. We find how the vortex lattices without the Rabi coupling known before are connected to the Abrikosov lattice of integer vortices with increasing the Rabi coupling. In this process, vortex dimers change their partners in various ways at large couplings. We then find that the Abrikosov lattices are robust in three-component BECs.     

A high-dynamic-range CMOS image sensor for automotive applications

In this paper, a 256×256 pixel CMOS imager is described that exhibits 120 dB dynamic range, 56 dB signal-to-noise ratio (SNR), 65% fill factor, and an effective frame rate of 50 Hz. This has been achieved using a unique combination of a multiexposure and a multigain linear readout. The imager has been integrated in 1 μm double-metal CMOS technology. The intended application is for driver's assistant systems, but the imager can be used for a wide range of applications requiring high dynamic range     

Comparison of tensile properties in the pre-yield region of metallocene-catalyzed and Ziegler-Natta-catalyzed linear polyethylenes

The mechanical nonlinear behaviour of metallocene- and Ziegler-Natta catalyzed polyethylenes with various contents of short chain branching was investigated using a nonlinear constitutive equation in which the plastic deformation and the anharmonicity of elastic response are taken into account. It is suggested that the mechanical behaviour is governed by the plastic deformation for the Ziegler-Natta catalyzed polyethylenes, whereas the anharmonicity strongly affects the mechanical behaviour for metallocene-catalyzed polyethylenes.     

Parallel phase-shifting digital holography with adaptive function using phase-mode spatial light modulator

Parallel phase-shifting digital holography using a phase-mode spatial light modulator (SLM) is proposed. The phase-mode SLM implements spatial distribution of phase retardation required in the parallel phase-shifting digital holography. This SLM can also compensate dynamically the phase distortion caused by optical elements such as beam splitters, lenses, and air fluctuation. Experimental demonstration using a static object is presented.     

Measurements of biological contaminants and particulate matter inside a dwelling in Japan

To investigate the biological contaminant levels inside dwellings in Japan, the authors measured fungal indices, airborne mite allergens (Der 1 and Der 2), and suspended particulate matter (SPM). Measurements were continuously conducted at one dwelling located in Yokosuka-city, Kanagawa. The biosensors for fungal index were set at 12 points inside and 2 points outside the dwelling. An SPM sampler was placed in the living room, and samplers for collecting allergens were placed in the living room and in the washroom. The peak level of the fungal index was recorded during July, which is the rainy season in Japan. The highest value in the dwelling was 6.9 in the toilet, and the second highest was 6.6 near a window in the living room that faces southeast, and behind the sofa. The highest monthly SPM level was 21.5 micrograms/m3 during October, and the highest monthly allergen level (Der 1) in the living room was 25.7 pg/m3 during November. A positive relationship between the fungal index and mite allergens was not observed, and the levels of contaminants were not as those found in other studies. However, further study to investigate the distribution of biological contaminants is needed because indoor temperature and relative humidity are comparatively high.