Observation of vasospasm after subarachnoid hemorrhage by magnetic resonance angiography--a preliminary study

Serial evaluation of cerebral vasospasm following subarachnoid hemorrhage was attempted in 11 patients using magnetic resonance (MR) angiography. MR angiography demonstrated vasospasm with angiographic confirmation in three patients as a segmental narrowing or loss of flow signal, usually accompanied by decreased distal flow signal. MR angiography also showed decreased flow signal suggestive of vasospasm in another patient with clinical evidence of vasospasm but no angiographic confirmation was possible because of poor condition. MR angiography showed no vasospasm in five patients without clinical evidence of vasospasm, except in one patient with disappearance of the unilateral anterior cerebral artery signal, shown to be involvement of the clipped artery. MR angiography is a potential method for detection of vasospasm with further improvement of the technique.     

Clinical evaluation of polymerase chain reaction DNA amplification method for the diagnosis of pulmonary tuberculosis in patients with negative acid-fast bacilli smear

The nucleotide sequences of 3 cDNA clones corresponding to entire RNA genome of bean common mosaic virus NL3 strain have been determined. The RNA is 9612 nucleotides long, excluding a 3'-terminal poly(A) tail. A putative start codon located at nucleotide positions 170-172 initiates one large open reading frame that is terminated with a UAA codon at position 9368-9370. The predicted polyprotein has 3066 amino acids and an M(r) of 340.3 kDa. The positions of putative protein cleavage sites have been determined by analogy to consensus sequences in other potyviruses. The nucleotide sequences of the non-translated regions and the predicted amino acid sequences of BCMV NL3, were compared with those of other potyviruses. Comparison of the BCMV NL3 proteins with those of other potyviruses indicated a similar genomic organization, and high percentage of amino acid sequence identity in the cylindrical inclusion protein, nuclear inclusion 'b' protein and coat protein. BCMV NL3 displays the highest amino acid sequence identity with soybean mosaic virus.     

Development of a recombinant ε-poly-L-lysine synthetase expression system to perform mutational analysis

ε-Poly-L-lysine (ε-PL) synthetase (Pls), which is a membrane protein with adenylation and thiolation domains characteristic of the nonribosomal peptide synthetases, catalyzes polymerization of L-lysine molecules (25-mer to 35-mer). Here, we report on the development of a recombinant Pls expression system that allowed us to perform a site-directed mutational analysis.     

Reconstitution and function of Tetragenococcus halophila chaperonin 60 tetradecamer

Tetragenococcus halophila originally isolated from soy sauce is a halophilic lactic acid bacterium which can grow under 4 M sodium chloride. T. halophila chaperonin composed of a core moiety of chaperonin 60 (cpn60) and a lid moiety of chaperonin 10 (cpn10), is thought to contribute to host halotolerant capability. In this report, we reconstituted and characterized the core complex of T. halophila chaperonin by using a recombinant T. halophila cpn60 (Tcpn60) overexpressed in Escherichia coli. The reconstitution of Tcpn60 was performed in the presence of 10 mM MgCl2, 2 mM ATP and 0.8 M (NH4)2SO4 and the resultant oligomer was purified by gel filtration chromatography. Electron microscopy of the reconstituted Tcpn60 revealed a double toroidal tetradecameric structure that is characteristic of bacterial cpn60. The T. halophila tetradecamer cpn60 exhibited an ATPase activity and a refolding activity of both chemically and thermally denatured enolases under wide range of salt concentrations. Furthermore, we demonstrated that heterologous expression of Tcpn60 allowed the normal growth of host Escherichia coli cells under salt stress conditions and this effect was further enhanced by co-expression with Tcpn10. These results suggested that Tcpn60 contributes to the halotolerance property of T. halophila cell as a tetradecamer complex, probably associated with the Tcpn10 complex.     

Wheel/rail contact geometry on tight radius curved track: simulation and experimental validation

In this investigation, a numerical procedure for wheel/rail one and two-point contact geometry analysis is developed for predicting the location of contact points in curved negotiations on a tight radius curved track. The proposed method accounts for the change in the longitudinal location of contact point along the curved track as well as the circumferential contact point on the wheel flange. For the purpose of validation, simulation results for one and two-point contact scenarios are compared with those obtained using the experiment. The experiment is performed on a test track of R48 curve using an actual truck, and the location of contact points for given lateral and yaw displacements are measured on the tight radius curved track. It is demonstrated that good agreements are obtained between the simulation and experimental results in tread and flange contacts.     

Separation of Nd metal by using disproportionation reaction of Nd(II) in molten chlorides

In order to separate neodymium (Nd) from lanthanides in chloride melts, the electrochemical characteristics Nd ions in molten LiCl-CaCl₂ eutectic were studied. The formal redox potentials of the Nd³⁺|Nd²⁺ and Nd²⁺|Nd couples in molten LiCl-CaCl₂ eutectic at 823 K were determined to be −2.745 ± 0.005 and −3.081 ± 0.005 V vs. Cl₂|Cl⁻. Under the controlled potential electrolysis by applying negative potential to form Nd²⁺, Nd²⁺ was disproportionated to Nd³⁺ and metallic Nd fog according to the reaction; 3Nd²⁺ ? 2Nd³⁺ + Nd. When a quartz glass was immersed in the melt during the electrolysis, Nd was coated on the quartz surface. The chemical composition of the recovered Nd was analyzed to be Nd metal and Nd₂O₃ by scanning electron microscopy, X-ray diffractometry, and electron probe microanalysis. The same electrolytic method was carried out under the coexistence of Nd³⁺ and lanthanum ion (La³⁺). Nd³⁺ was separated from La³⁺ and recovered to be Nd₂O₃.     

Numerical evaluation of group-pile foundation subjected to cyclic horizontal load

In this paper, three-dimensional (3D) finite element analyses of a real-scale group-pile foundation subjected to horizontal cyclic loading are conducted using a program named DBLEAVES. In the simulations, nonlinear behaviors of ground and piles are described by subloading t_ij model and the axial-force dependent model (AFD model) which considered the axial-force dependency in the nonlinear moment-curvature relations. In order to consider the influence of an effective stress path on the prediction of the group-pile foundation, the analyses are conducted within the framework of the soil-water coupling method with finite-difference and finite-element regime. The material parameters of soils are determined based on conventional triaxial drained compression tests on undisturbed and remolded specimens. The applicability of the proposed numerical method is encouraging, and therefore, it is quite confident to say that the method can be used to predict the mechanical behaviors of group-pile foundation to a satisfactory accuracy, particularly with the effective stress analysis.     

Liquefaction of palm kernel shell in sub- and supercritical water for bio-oil production

The heavy palm oil industry in Malaysia has generated various oil palm biomass residues. These residues can be converted into liquids (bio-oil) for replacing fossil-based fuels and chemicals. Studies on the conversion of these residues to bio-oil via pyrolysis technology are widely available in the literature. However, thermochemical liquefaction of oil palm biomass for bio-oil production is rarely studied and reported. In this study, palm kernel shell (PKS) was hydrothermally liquefied under subcritical and supercritical conditions to produce bio-oil. Effects of reaction temperature, pressure and biomass-to-water ratio on the characteristics of bio-oil were investigated. The bio-oils were analyzed for their chemical compositions (by GC–MS and FT-IR) and higher heating values (HHV). It was found that phenolic compounds were the main constituents of bio-oils derived from PKS for all reaction conditions investigated. Based on the chemical composition of the bio-oil, a general reaction pathway of hydrothermal liquefaction of PKS was postulated. The HHV of the bio-oils ranged from 10.5 to 16.1 MJ/kg, which were comparable to the findings reported in the literature.     

Crystal Growth of Rod-Shaped β-LiA1O2

LiAlO₂crystals are obtained conventionally in the form of powder. In a few publications, crystal growth of rod-shaped LiAlO₂ has been described, but the fiber length was very short, <4 μm. In the present study, rod-shaped β-LiAIO₂ crystals 10 to 15 μm long were grown using LiOH-AI₂O₃NaOH as the raw material.     

Field test of liquid nitrogen cooled cryogenic power cable

A liquid nitrogen cooled cryogenic cable, 66 kV, 100 MVA, 30 m was constructed and tested with loads simulating actual operating loads from October 1970 to December 1971. The successful operation of the cable makes us hopeful it can be used for large capacity transmission. Our test line is composed of aluminium stranded hollow conductor, liquid-nitrogen impregnated polyethylene paper electrical insulation, and polyurethane foam thermal insulation.