Easy Method for the Approximate Quantitation of 4-Methylthio-3-Butenyl Isothiocyanate of Daikon (Raphanus sativus L.)

Daikon (Japanese white radish, Raphanus sativus L.) is widely consumed across Japan. The characteristic pungent flavor of daikon is derived from 4-methylthio-3-butenyl isothiocyanate. Herein, we propose an easy method for the approximate quantitation of this compound. This method does not require an expensive analytical apparatus such as a high-performance liquid chromatograph but only an ultra violet-visible spectrophotometer to measure the absorbance of a daikon n-hexane extract, at 231 nm, against a standard. The estimation of the concentration of 4-methylthio-3-butenyl isothiocyanate by this method can sort the pungency of daikon, because this isothiocyanate is a principal isothiocyanate of daikon.     

Effect of surface properties of calcium carbonate on aggregation process investigated by molecular dynamics simulation

The control of the morphology and polymorphs of CaCO₃ has been required, since their capabilities are dependent on particle characteristics of CaCO₃. It is difficult to clarify the formation mechanism only by the experimental approaches because the nucleation and crystal growth of CaCO₃ occurred at nanoscale. The objective of the present work is to investigate the effect of surface properties including in the charge density and the dielectric constant of water on the aggregation process of primary particles by means of molecular dynamics simulations. The grain boundary energy was also calculated by molecular dynamics simulation to investigate the change of energy in the aggregation process of primary particles. From the results of molecular dynamics simulation, we found that the interface of (001)Ca and (001)CO₃ contacted with water charged positively and negatively and the interface of (100) and (104) contacted with water charged neutrally. When the distance of interfaces between CaCO₃ particles came close to colliding, the dielectric constant of water became small except the interface of (001)CO₃. The boundary energy of interface between (001)Ca and (001)CO₃ was the lowest among five types of interfaces. It indicates that the aggregation of (001)Ca and (001)CO surface is the easiest among all types of interfaces.     

Automatic estimation of the ergonomics parameters of assembly operations

The ergonomics of assembly operations affects standard operation times and assembly reliability. It is a complicated time-consuming task to estimate the ergonomics parameters of operations in assembly cells. Assembly operations are simulated in a virtual environment, and ergonomic parameters including the visibility of an assembling part, posture and reachability of an operator are quantified automatically by using images of the assembling part which are automatically generated. The highest score among the image is selected as the ergonomics score of the assembly operation. The proposed method is tested by applying it to the assembly operations of a PC. Results demonstrated the feasibility of the proposed method.     

Occurrence of severe vasospasm following intraventricular hemorrhage from an arteriovenous malformation. Report of two cases

The authors present two rare cases of severe cerebral vasospasm following the rupture of arteriovenous malformations (AVMs). Computerized tomography revealed intracerebral hemorrhage in the thalamus in one case and in the putamen in the other, both accompanied by cast formation of intraventricular clots without radiological evidence of subarachnoid hemorrhage. Initial angiograms showed arterial narrowing of the bilateral internal carotid arteries in the supraclinoid portion but failed to demonstrate an arteriovenous shunt. Subsequent angiograms clearly demonstrated the existence of an AVM. Radiological features and possible mechanisms are discussed.     

Desiliconization and decarburization behavior of molten Fe-C-Si(-S) alloy with CO<Subscript>2</Subscript> and O<Subscript>2</Subscript>

One of the most important problems in the steelmaking process is an increase of the disposal slag mainly discharged from the dephosphorization process. In order to reduce the quantity of the disposal slag, the complete removal of silicon from molten pig iron is considered very effective before the dephosphorization in the pretreatment process. From this point of view, the desiliconization and the decarburization behavior of Fe-C-Si alloy with CO₂ and O₂ has been investigated in the present work. It is thermodynamically calculated that silicon should be oxidized in preference to carbon over 0.60 mass pct Si under the condition of s_SiO2=a _C=1 at 1573 K and is experimentally confirmed that silicon is only oxidized under the condition in actual. Even under the competitive region of desiliconizing and decarbonizing, under 0.60 mass pct Si, silicon is found to be oxidized down to about 0.1 mass pct Si in preference. The overall rate constants for the desiliconization and the decarburization are derived, and the value for the desiliconization is one order of magnitude larger than that for the decarburization. The influence of sulfur is also examined, and the retarding effect is not observed on the oxidation reactions.     

Endotoxin and its binding protein in organ failure

Endotoxin (lipopolysaccharide: LPS) infection due to bacterial translocation is intimately involved in the organ failure that occurs after highly invasive interventions such as extensive liver resection, and has attracted a great deal of interest. LPS that has translocated into portal blood binds to LPS-binding protein (LBP) and is transported to the monocytes and Kupffer cells in liver sinusoids where it is activated through the soluble CD14 that is present on their cell membranes or in blood plasma. Inflammatory cytokines such as TNF-alpha and IL-6 are produced and released by monocytes and Kupffer cells that have been activated by LPS-LBP complexes, and the endothelial cell of the sinusoids is damaged by these inflammatory cytokines. The original anticoagulant function of the damaged endothelial cells is reduced, and microcirculatory insufficiency is caused by the formation of microthrombi. It is important to understand this network mechanism and to prevent invasion, and attention has recently been focused on LBP and CD14 because of this point. The increase in LPS as a result of extensive liver resection, which is highly invasive, begins 3 hours after surgery, and peaks at 6 hours. LBP, however, is awaiting the entry of LPS, principally in the periportal hepatocytes. Its production peaks at 12 hours, and this is related to the excessive production of inflammatory cytokines have been produced, expression of LBP must be suppressed within 12 hours to inhibit this excessive reaction, and that will be the task of a future study.     

Spatial cone activity distribution in diseases of the posterior pole determined by multifocal electroretinography

Thirty patients with a reduced central vision due to diseases of the posterior pole were examined with the VERIS system developed by Sutter and Tran (Vis Res 1992;32:433-446) to characterize the topography of electroretinographic (ERG) changes in comparison to the results in 30 normal volunteers. Diagnoses included Stargardt's macular dystrophy (SMD, n = 10), age-related macular degeneration (AMD, n = 5), cone dystrophy (CD, n = 5), central retinal vein occlusion (CRVO, n = 5), and autosomal dominant optic atrophy (ADOA, n = 5). The 61 local responses obtained from each subjects were grouped by eccentricity to form five concentric rings. The foveal ERG, originating from a central area of 2 degrees radius, was non-recordable or markedly diminished in all patients except those with optic atrophy, where amplitudes were found to be in the normal range. In patients with advanced stages of SMD, functional defects were larger and involved more peripheral areas than in patients with early stages of SMD or with AMD. A reduction of response amplitude even in the most peripheral ring (17-30.5 degrees eccentricity) was found in cone dystrophies and--moderately--in patients with advanced SMD and central retinal vein occlusion only. Prolonged implicit times were found in all but the patients in early stages of SMD and they were maximal in patients with CRVO. This study shows that the multifocal ERG (MFERG) can contribute to differential diagnosis of retinal diseases of the posterior pole especially in cases with a normal photopic Ganzfeld ERG.     

Parasympathetic activity is a major modulator of the circadian variability of heart rate in healthy subjects and in patients with coronary artery disease or diabetes mellitus

Autonomic heart rate control was assessed by power spectral analysis of heart rate variability in 24-hour ambulatory electrocardiographic recordings from 23 healthy subjects, 14 patients with coronary artery disease without cardiac dysfunction, and 14 patients with diabetes mellitus. The log value of the ratio of the low-frequency component (LF = 0.04 to 0.15 Hz) to the high-frequency component (HF = 0.15 to 0.5 Hz) and logHF were employed as indexes of sympathetic and parasympathetic activity, respectively. Diurnal and nocturnal logLF, logHF, and log(LF/HF) values were calculated for heart rates of 60, 70, and 80 beats/min. Intergroup differences among these three variables were not significant at any heart rate. Although a heart rate-related decrease in logHF was generally observed, the relationship between log(LF/HF) and heart rate was not consistent. The correlation between diurnal and nocturnal logHF values was significant at all three heart rates (r = 0.63, 0.87, and 0.59), whereas the diurnal log(LF/HF) was correlated with the nocturnal value only at 70 beats/min (r = 0.77). These results suggest that the heart rate during normal daily activities is a reliable indicator of parasympathetic tone, if not sympathetic tone, in healthy subjects and patients with coronary artery disease or diabetes mellitus.     

Anisotropic lattice coherency of GaAs nanocrystals deposited on Si(100) surface by molecular beam epitaxy

Lattice coherency and morphology of GaAs nanocrystals grown on Si(100) substrate have been studied by transmission electron microscope in order to see growth mechanism of the nanocrystals. GaAs nanocrystals consisting of four {111} facet planes and a rectangular basal plane with four sides along [01 ] and [011] directions have grown on the Si surface. Either (011) or (01) lattice planes along the minor axis on the rectangular basal plane in the GaAs nanocrystal are completely-coherent with {011} lattice planes in the Si substrate. On the other hand, another (01) or (011) lattice planes along the major axis are partially-coherent with those in the Si substrate. When the lattice planes of the either (011) or (01), which is randomly determined by local atomic structures, become partially-coherent with those in the Si substrate to relax accumulated lattice strain, the growth rate of nanocrystal is remarkably increased along the direction parallel to unstrained (011) or (01) planes which prevents from each area of the strained {011} planes in the nanocrystals increasing. The anisotropic lattice coherency between the GaAs nanocrystals and the Si substrate causes the anisotropic morphology of the GaAs nanocrystals which is elongated the directions parallel to the strained {011} planes.