Protein modelling using a chimera reference protein derived from exons

Bovine pancreatic /S-trypsin (PDB ID-code: 1TPO) which is registeredin the Brookhaven Protein Data Bank (PDB) consists of four exons.The results of homology searches for each exon in the PDB showedthat homologous proteins were tonin (PDB ID-code: 1TON), ratmast cell protease (PDB ID-code: 3RP2_A), kaffikrein A (PDBID-code: 2PKA_B) and kallikrein A (2PKA_B) respectively. Thus,for the three-dimensional structure prediction of 1TPO, a chimeraprotein was constructed from the three proteins mentioned aboveand the 3-D structure prediction was performed using this chimerareference protein. The modelled structure of 1TPO was energeticallyoptimized by molecular mechanics and molecular dynamics simulationand was compared with its X-ray crystal structure registeredin the PDB. The root mean square deviations (r.m.s.d.) of mainchain atoms and the neighbouring active site (5 sphere fromHis57, AsplO2 and Serl95) between the modelled structure andthe X-ray structure were 1.66 and 0.94 respectively. Porcinepancreatic elastase (PDB ID-code: 3EST) which is registeredin the PDB was used as the reference protein and the modelledstructure from 3EST was also compared with the X-ray data. Ther.m.s.d. of main chain atoms and that of the active site were2.14 and 1.18 respectively. These results dearly support thepropriety of this method using the chimera reference protein.     

Stability of tetragonal ZrO2 phase in Al2O3 prepared from Zr-Al organometallic compounds

Zr-Al organometallic compounds have been spray-dried and heated at temperatures 600 to 1400°C to prepare ZrO₂-Al₂O₃ composite powders. The powders consist of balloon-like particles 0.5 to 2 m in diameter with homogeneously dispersed tetragonal ZrO₂ grains 0.1 to 0.2 m in diameter. The tetragonal fraction of ZrO₂ in the composite powders is higher than that in the powders prepared from sols of Zr(OBuⁿ)₄ and Al[OCH(CH₃)₂]₃. The fraction is affected by the organofunctional group in the Zr-Al compounds.Zr(OBuⁿ)₄ = Zr(OC₄Hgⁿ)₄; Al[OCH(CH₃)₂]₃ = Al(OPrⁱ)₃.     

"Pored-domes" of the fenestrated endotheliocyte of the glomerular and peritubular capillaries in the rodent kidney.

The fenestrated endotheliocyte of peritubular and glomerular capillaries in rat and mouse kidneys were observed with SEM and TEM. In the glomerular capillary, so-called "pored-domes" were found not only at the fenestrated areolae but also at the nuclear region of the endotheliocyte. At the region between filtration surface and nuclear region, they accumulated to construct a sponge-like structure. The endotheliocyte of peritubular capillary also showed small "pored-domes". The size and morphology of the pores in the "pored-domes" of glomerular and peritubular capillaries were similar to those of areolae fenestratae of the respective capillary. Based on the findings, we assumed that pored-domes and the sponge-like structure are the reservoir for the fenestrated area of the endotheliocyte to accommodate the rapid expansion of capillary lumen.     

An experimental study of the thermodynamic properties of 1,1-difluoroethane

Experimental vapor pressures andP--T data of an important alternative refrigerant, 1, 1-difluoroethane (HFC-152a), have been measured by means of a constant-volume method coupled with expansion procedures. SixtyP--T data were measured along eight isochores in a range of temperaturesT from 330 to 440 K, at pressuresP from 1.6 to 9.3 MPa, and at densities from 51 to 811 kg·m^–3. Forty-six vapor pressures were also measured at temperatures from 320 K to the critical temperature. The uncertainties of the temperature and pressure measurements are within ±7mK and ±2kPa, respectively, while the uncertainty of the density values is within ±0.1%. The purity of the sample used is 99.9 wt%. On the basis of the measurements along each isochore, five saturation points were determined and the critical pressure was determined by correlating the vapor-pressure measurements. The second and third virial coefficients for temperatures from 360 to 440 K have also been determined.     

Co-crosslinking blend of incompatible polymers VI: Poly(vinyl chloride) toughened with polyethylene via a co-crosslinking technique

A binary blend which consists of two incompatible polymers such as poly(vinyl chloride) and polyethylene has been performed through a partial co-crosslinking reaction with peroxide to give a co-crosslinked blend with a uniform dispersion of small polyethylene particles and with an improved mechanical property. The results are obtained through the formation of a co-crosslinked product which acts as a potential solid phase dispersant as well as a well-bonded reinforcing interlayer on polyethylene particles uniformly dispersed in poly(vinyl chloride) matrix. The resulting blends (PVC/PE=10/90 wt) give carbon spherules of 0.5 to 1m diameter through pressure-carbonization at 650° C for 1 h.     

Autonomous Visual Measurement for Accurate Setting of Workpieces in Robotic Cells

This paper introduces a new method of adapting the virtual world of an offline programming model to an actual robotic cell by attaching a CCD camera to the robot. This method requires no specific camera attachment location or optical camera calibration. Furthermore, there is no operational requirement for setting robotic camera location. Robot motion is autonomously generated to identify the camera view line. The view line is adjusted to pass through the designated target point, utilizing visual feedback motion control. This method calibrates reference points between the virtual world of an offline model to an actual robotic cell.     

Breakdown Trade-Off Relation of Mechanical Properties via Micro-alloying in Mg–Mn Alloys

The impact of micro-alloying on tensile behavior at strain rates in various ranges is examined using five types of extruded Mg-0.3 at. pct Mn–0.1 at. pct X ternary alloys, where X is selected as a common element, Al, Li, Sn, Y or Zn. Microstructural observations reveal that the average grain size of these extruded alloys is between 1 and 3 μm, and these micro-alloying elements segregate at grain boundaries. In room temperature tensile and compression tests, these results show that the mechanical properties and deformation behavior are influenced by the micro-alloying element, even as a small addition of 0.1 at. pct. Mg–Mn–Y and Mg–Mn-Zn alloys show higher strength and smaller strain rate sensitivity (m-value) among the present alloys, owing to the rate-controlling mechanism as dislocation slip. On the other hand, the Mg–Mn–Li alloy exhibits the largest elongation to failure in tension and the highest strain rate sensitivity, associated with high contribution of grain boundary sliding to deformation. These differences are due to the grain boundary segregation of the micro-alloying elements. Compared to the common Mg alloys, the present ternary alloys also show a trade-off relationship between strength and ductility, which is similar to that of the well-known Mg alloys; however, these properties of the Mg–Mn system ternary alloys could be controlled via the type of micro-alloying elements with a chemical content of 0.1 at. pct.

     

Use of LINbO3 for Design of Device-type Catalysts with Activity Controllable Functions

A poled ferroelectric LiNbO₃ single crystal with high spontaneous polarization was employed as a catalyst support, and the static and dynamic effects of the polar substrate surfaces on the adsorptive and catalytic properties of thin film catalysts deposited were shown. For the static effect, it was demonstrated that the surface conductivity of copper and metal-free phthalocyanine films increased by the adsorption of NO gas, to a larger extent, when the substrate was the negative polar surface, compared to the positive one. The role of the polar substrates is explained In terms of a band bending model. For the dynamic effect, the Rayleigh surface acoustic wave generated on the LiNbO₃ substrate was shown to enhance the catalytic activity for ethanol oxidation on Cu and Ag thin film catalysts deposited on the propagation path. It is proposed that the catalyst activation is mainly due to an electric Held produced. The use of poled LiNbO₃ is suggested to be effective for the development of a device-type catalyst with activity controllable functions.     

Mechanical Properties of Alumina/Silicon Carbide Whisker Composites

The improvement of mechanical properties of Al₂O₃/SiC whisker composites has been studied with emphasis on the effects of the whisker content and of the hot-pressing temperature. Mechanical properties such as fracture toughness and fracture strength increased with increasing whisker content up to 40 wt%. In the case of the high SiC whisker content of 40 wt%, fracture toughness of the sample hot-pressed at 1900° decreased significantly, in spite of densification, compared with one hot-pressed at 1850°. Fracture toughness strongly depended on the microstructure, especially the distribution of SiC whiskers rather than the grain size of the Al₂O₃ matrix.     

Effects of bile acid feeding on hepatic deoxycholate 7α-hydroxylase activity in the hamster

In order to investigate the effects of bile acid feeding on hepatic microsomal deoxycholate 7α-hydroxylase activity, three different bile acids were administered (0.2% w/w in chow) to hamsters for two weeks. Deoxycholate 7α-hydroxylase activity was increased markedly by feeding of cholic acid (CA) and slightly by deoxycholic acid (DCA) Chenodeoxycholic acid (CDCA) had little effect on the enzyme activity. Feeding each of the bile acids significantly inhibited the activity of cholesterol 7α-hydroxylase in the order CDCA≥ DCA>CA. There was no correlation between deoxycholate 7α-hydroxylase activity and cholesterol 7α-hydroxylase activity. It is concluded that the activity of deoxycholate 7α-hydroxylase is up-regulated by feeding DCA and CA and that the mechanism seems to be different from that of cholesterol 7α-hydroxylase. The increased activity of hepatic deoxycholate 7α-hydroxylase by CA and DCA should be beneficial in minimizing the toxic effects of DCA in the hamster.