Search

An inter-method variation experiment to evaluate visible spectrophotometric methods for determining carboxyhemoglobin (CO-Hb) in blood was performed in 17 different forensic science laboratories. Three reference samples were prepared and the actual percentages of CO-Hb (%CO-Hb) in reference samples were determined with gas chromatography. The %CO-Hb values in reference samples were measured via four procedures: (1) the “Standard method of chemical analysis in poisoning 2017” (edited by the Pharmaceutical Society of Japan), (2) the isosbestic point method (developed by the Department of Forensic Medicine, Kagawa University), (3) the alkaline condition method, and (4) ISO 27368 with a slight modification. Procedures (1) and (2) gave results approximately the same as the actual values in low-%CO-Hb samples, but both methods underestimated %CO-Hb levels in blood samples with high %CO-Hb. Using a formula reported by Katsumata et al., procedure (3) overestimated %CO-Hb levels in blood samples with low %CO-Hb, while using the modified formula, gave underestimates in all samples. Procedure (4) gave %CO-Hb values relatively close to the actual values. Thus, an accuracy evaluation test was performed for this procedure and the values obtained were close to the actual CO-Hb content levels. Procedure (4) was considered sufficiently accurate and thus recommendable for use in forensic science laboratories.

We have investigated the use of liquid penetration to evaluate and detect structural differences in dried thin films. Two different films were fabricated from slurries that consisted of solid particles and a polymer. Both slurries had the same composition, but were prepared using different mixing processes. Clear differences in the void distributions of the as-prepared films were observed using mercury porosimetry. No significant differences were observed after the films were compressed. However, cross-sectional scanning electron microscopy images showed clear structural differences, including segregated particles after compression. Liquid penetration times into the films were measured and explained using a modified kinetic model. The wettability of the films using solvents of low polarity was also evaluated and was found to be dependent upon the extent of segregation within the films. This result suggested that liquid penetration measurements could be used as a simple method to evaluate the structure of particulate films.

A processing route to disperse carbon black (CB) nanoparticles in aqueous and various organic solvents was developed by a high-shear-agitated bead milling process in water with various cationic dispersant and further surface modification using anionic surfactant. First, for dispersing CB nanoparticles in an aqueous suspension, polyethyleneimine (PEI) and a new cationic dispersant, which was synthesized by the reaction of PEI with a hydrophobic toluoyl group (T-PEI), were used to stabilize CB nanoparticles in water during the bead milling process, and their results were compared. When PEI was used as a dispersant, the conditions for obtaining CB nanoparticles in water in a dispersed state were few and most additive conditions resulted in a segregated and inhomogeneous CB suspension. However, when T-PEI was used as a dispersant, a highly dispersed CB suspension was obtained under a wide range of T-PEI additive conditions, even when the additive amount was as low as 1.0 mg/m 2 . Next, for dispersing CB nanoparticles in various organic solvents, an anionic surfactant that branched into hydrophilic polyethylene glycol (PEG) and hydrophobic alkyl segments was adsorbed on CB nanoparticles stabilized with PEI or T-PEI. It was found that CB dispersible in various solvents could be obtained successfully only when the anionic surfactant was adsorbed on PEI-stabilized CB nanoparticles. The proposed action mechanism of each surfactant on the CB surface and its effect on the stability of CB in an aqueous/organic solvent are discussed.

The turning of straight micropins with a diameter smaller than 10 µm, which has not been reported so far, was carried out using micro turning tools made of cemented tungsten carbide. Tools of 50 µm diameter were fabricated by electrical discharge machining, which is suitable for fabricating micro cutting tools because it can deal with hard materials and carry out micromachining. A turning machine designed especially for micro turning tools was used in the experiments. A brass workpiece was turned using a tool with a length of cut of 100 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 10–11 µm. As a result, a straight micropin of 7.5 µm diameter and 80 µm length was successfully turned. Furthermore, turning was also performed using a tool with a length of cut of 50 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 8.5–20 µm to fabricate a straight micropin of 3 µm diameter and 30 µm length. This micropin is the pin with the smallest ever diameter fabricated by turning, to the best of our knowledge, indicating the possibility of further minimization of the machinable size in turning. Turning properties were also investigated to determine the maximum depth of cut and feed speed that can be employed without tool breakage.

Micro turning tools with outside diameters of 25–50 μm were fabricated using cemented tungsten carbide by electrical discharge machining and used for micro boring and micro face grooving. The new process used could improve the hole circularity down to 0.25 μm and provide smooth-finished surfaces. From a set of experiments, the limit depth of cut and feed rate that can prevent tool breakage were determined. Compared with previous studies, the current study paved the way for applying removing processes with micro tools to boring and face grooving.

To improve the electrical conductivity of negative electrodes of lithium ion batteries, we applied a direct CVD synthesis of carbon nanomaterials on the surface of graphite particles. To prepare a catalyst, two alternative approaches were utilized: colloidal nanoparticles (NPs) and metal (Ni and Co) nitrate salt precursors deposited on the graphite surface. Both colloidal and precursor systems allowed us to produce carbon nanofibers (CNFs) on the graphite surface with high coverage under the optimum CVD conditions. Electrical measurements revealed that the resistivity of the actual electrodes fabricated from CNFs coated graphite particles was about 40% lower compared to the original pristine graphite electrodes.

Immune complexes in glomeruli are involved in development of diverse glomerulonephritis. The disposal process of glomerular immune complexes has been unclarified. The present studies were undertaken to determine if thromboxane A2 (TXA2) is associated with the disposal of macromolecules in the glomeruli using mice injected with aggregated bovine serum albumin (a-BSA). A-BSA promptly accumulated in the glomeruli, the level reaching a plateau at 6 hr after the injection of a-BSA, and then decreased by 48 hr. The production of glomerular TXA2, prostaglandin E2 (PGE2) and prostaglandin I2 concomitantly increased with the decrease of a-BSA in the glomeruli. TXA2 synthase inhibitors and TXA2 receptor antagonists accelerated clearance of glomerular a-BSA without enhancing renal tissue blood flow. They did not affect a-BSA level in the plasma. In contrast, aminophylline, dopamine and mannitol significantly increased renal tissue blood flow, but did not decrease glomerular a-BSA. TXA2 synthase inhibitors decreased TXA2 production in the glomeruli. TXA2 synthase inhibitors and TXA2 receptor antagonists did not influence the generation of PGE2. The TXA2 analogue U-46619 significantly increased the accumulation of a-BSA in the glomeruli. We propose that TXA2 interferes with the disposal process of aggregated protein in the glomeruli. We also postulate that interception of glomerular activity of TXA2 may be an effective intervention for managing immune complex-mediated glomerulonephritis and glomerulosclerosis.

The purpose of this study was to investigate the characteristics of arachidonic acid-induced peripheral vascular disease in rats. Injecting arachidonic acid (2 mg/leg) into the femoral artery caused hind limb gangrene. Histopathological examination revealed occlusive thrombi and marked vascular injury, including denudation of the endothelium and degeneration of the media in the paw arteries. Arachidonic acid injection markedly enhanced the platelet response to both U-46619 and collagen. Although the number of circulating platelets did not differ between sham-operation rats and arachidonic acid-injected rats, the numbers of circulating white blood cells and red blood cells were raised 10 d after arachidonic acid injection. Thrombocytopenia, induced before arachidonic acid injection, markedly suppressed arachidonic acid-induced hind limb gangrene in rats. In addition, the combined administration of aspirin (100 mg/kg/d, p.o.) and ticlopidine (300 mg/kg/d, p.o.) prevented the progression of arachidonic acid-induced hind limb gangrene. These results suggest that platelets are involved in the progression of arachidonic acid-induced hind limb gangrene. This experimental rat model may be suitable for developing novel drugs for the treatment of peripheral vascular disease.

We investigated the pharmacological characteristics of Z-335 ((+/-)-sodium[2-[4-(chlorophenylsulfonylaminomethyl)indan-5-yl]ace tate monohydrate), a new indan derivative. Z-335 inhibited the specific binding of [3H]SQ-29548 to human platelets and guinea pig platelet membranes. The IC50 values of Z-335 for human platelets and guinea pig platelet membranes were 29.9 +/- 3.1 nM with a slope of 1.09 +/- 0.05 and 32.5 +/- 1.7 nM with a slope of 1.07 +/- 0.02, respectively. Z-335 inhibited thromboxane A2 receptor-mediated human and guinea pig platelet aggregation in vitro and oral administration of this drug to guinea pigs inhibited U-46619- and collagen-induced platelet aggregation for 24 h. Z-335 dose-dependently prevented the occurrence of U-46619-induced pulmonary thromboembolism in mice and the protective effect of this drug (0.3 and 3 mg/kg, p.o.) lasted for 24 h. These results strongly suggest that Z-335 is a potent, orally active and long-lasting thromboxane A2 receptor antagonist, which may be useful as an antiplatelet drug.