Relative reactivity of phenylboronic acid to phenylboronate ion toward L-lactate and mandelate at physiological pH

Kinetic studies were performed on the reactions of phenylboronic acid with L-lactic acid and mandelic acid in acidic aqueous and alkaline solutions in order to specify reactive species in these reactions. It was confirmed that the diprotonated ligand (H₂L: L-lactic acid or mandelic acid) is less reactive than the monoprotonated ligand (HL^?: L-lactate ion or mandelate ion), which made possible direct determination of the rate constants of phenylboronic acid (PhB(OH)₂) and its conjugate base, phenylboronate ion (PhB(OH)₃^?). It was found that PhB(OH)₂ is more reactive than PhB(OH)₃^?. On the basis of kinetic results, it was concluded that the most reactive species are PhB(OH)₂ and HL^? at physiological pH 7.4, so the reaction in the boronic acid-based sensor for L-lactate mainly would occur between these species.     

Role of protein kinase Cbeta in rhythmic contractions of human pregnant myometrium

To assess the role of protein kinase Cbeta (PKCbeta) in human myometrial contractions during pregnancy, we evaluated the effect of a PKCbeta inhibitor (LY333531) on the pregnant and nonpregnant myometrial contractions and compared the level of PKCbeta in the pregnant myometrium with that in the nonpregnant myometrium. The effects of LY333531 on the myometrial contractions were examined by measuring contractile activity (frequency and amplitude). PKCbeta in human myometrium was assessed at mRNA level using real-time PCR method. The characteristics of contractile activity were different between the pregnant and the nonpregnant myometrium. The amplitude of rhythmic contractions in the preterm and term myometrium was increased 2- to 2.5-fold when compared with that in the nonpregnant myometrium, but the frequency of rhythmic contractions was decreased by about half. LY333531 (10(-6) M) reduced the increased amplitude in the preterm and term myometrium by about 50%, and the inhibitory effects of LY333531 in the pregnant myometrium were significantly greater than that in the nonpregnant myometrium (about 50 vs 25%). However, the frequency in the pregnant and nonpregnant myometrium was not influenced by LY333531. Real-time PCR revealed a significant, five- to sevenfold increase in the expression of PKCbeta mRNA in the preterm and term myometrium when compared with the nonpregnant myometrium. These findings suggest that the increased amplitude of human myometrial contractions during pregnancy is related to the increased level of PKCbeta. A PKCbeta inhibitor may reduce preterm uterine contractions and prevent preterm delivery.     

Effect of pressure and temperature on the molecular interaction of polar lubricant containing oleic acid in polypropylene glycol observed by infrared spectroscopy

In this work, we have investigated the infrared spectra of polar lubricant in order to explore the molecular interaction under high pressure and temperature conditions using diamond anvil cell. Polypropylene glycol and oleic acid were used as base oil and additive, respectively. Stretching vibration mode of polar functional groups, such as ν _O–H and ν _C═O, was found to be sensitive to pressure and temperature. The peak positions of the vibration mode were shifted clearly to lower wavenumber as pressure increases, and temperature increase induced a slight shift to higher wavenumber. These results indicate that hydrogen bonding between lubricant molecules of base oil and additive was influenced by pressure and temperature. And furthermore, the dependency of the peak shift was discontinuous and affected mainly by pressure. These results imply a structural change on the basis of the molecular interaction of the lubricating molecules at elastohydrodynamic lubrication contacts. Copyright © 2013 John Wiley & Sons, Ltd.     

Prediction of Aeroelastic Vibration of Rectangular Cylinders by k-ε Model

The applicability of the k-ε model in the prediction of aerodynamic force and instability is investigated herein. To show that two-dimensional analysis by the k-ε model is different from ordinary two-dimensional analyses that simply neglect the spanwise velocity, an analysis of the aeroelastic vibration of a cross section with B∕D = 2.0 is performed first using the latter method. In this case, motion-induced vortex oscillation was successfully simulated; however, galloping, in which the flapping motion of the separated shear layer plays an important role, could not be simulated. The result shows that physically reasonable flows can not be obtained by ordinary two-dimensional analyses, unless the spanwise momentum diffusion is incorporated correctly. On the other hand, the k-ε model, which incorporates this diffusion process by an eddy viscosity, enables two-dimensional analyses even in the high Reynolds number region. In this paper, applicability of the model is examined for rectangular cross sections with a wide range of B∕D ratio, i.e., 0.6 ≤ B∕D ≤ 8.0. Various typical aerodynamic features calculated using this model were found to be in good agreement with those obtained experimentally, particularly including discontinuities in Strouhal number at the critical cross sections of B∕D = 2.8 and 6.0. Based on this result, an elastically supported B∕D = 2.0 cylinder was analyzed. The motion-induced vortex oscillation and a coupling of the vortex-induced oscillation and galloping were successfully simulated, and their values were in good agreement with those measured in experiments conducted earlier.     

Economical clean dry air system for closed manufacturing system

We demonstrated that the organic carbon contaminants influenced the J-E characteristics of a gate oxide. Molecular-contamination-free clean dry air (CDA) is a choice for the atmosphere control in a closed manufacturing system. The adsorption and desorption characteristics, which are important items for the design and operation of CDA production plants, were confirmed with both a dynamic simulation and a pilot column. Based on the results, we built a CDA plant with a capacity of 4000 m³/h, and confirmed that each contamination concentration was less than 10 ppb. We also proposed the economical CDA system using a power recycle device which has been newly developed. Using this CDA system, it is possible to reduce the power consumption in the CDA plant. Also, it is possible to realize the circulation of the used CDA without generating more contamination or power consumption     

Design and performance evaluation of a haptic interface based on MR fluids for endovascular tele-surgery

Microsystem Technologies - In this paper, a magnetorheological (MR) fluids based haptic interface has been developed in master site to provide the haptic sensation to the interventionalist during...     

Isolated retrograde amnesia following viral encephalitis

We describe a patient who presented with isolated retrograde amnesia of 2-year duration after recovery from viral encephalitis. The patient was a 29-year-old right-handed male dentist and was admitted to our hospital with a complaint of generalized convulsion. Cerebrospinal fluid (CSF) showed mononuclear pleocytosis. Neuroradiological examinations (X-ray CT, MRI and 123I-IMP SPECT) revealed no significant abnormality. Immunological method showed no specific increase of viral antibody titers. However, with a tentative diagnosis of viral encephalitis, administration of acyclovir was started. After 3 weeks he became comprehensive, and several kinds of neuropsychological tests were performed. His intelligence and immediate memory were normal, and his procedural memory of dentist was intact. On the other hand, he could not recall any information about events, both personal and public, occurred within 2 years before the onset of present illness. His autobiographical memory disorder was also demonstrated using a series of weekly comic. In isolated retrograde amnesia following viral encephalitis like this case, memory of relatively short time duration, acquired prior to the onset of present illness, tend to be disturbed.     

Field emission monotron for THz emission

Small-signal negative conductance of a field emission monotron was calculated, which was considerably higher than that of a thermionic monotron due to strong bunching of emitted electrons in a field emission. The amplification constant of 28dB/mm is achieved at THz wave region by applying the monotron to a distributed amplifier and is sufficient to overcome power loss in a transmission line. In addition, a wide band frequency tunable electromagnetic wave source may be developed at THz wave region by providing a low loss microstrip line resonator with field emission array due to the gate voltage dependent phase constant of the line.     

Effects of electrolyte pH and temperature on dielectric properties of anodic oxide films formed on niobium

The effects of electrolyte pH and temperature on the structure and properties of anodic oxide films formed on niobium in phosphoric acid solution with the addition of NH₄OH for pH adjustment have been investigated. The film thickness formed at the same voltage slightly increased with increasing pH and significantly increased with increasing electrolyte temperature. The capacitance of the film was independent of electrolyte pH in an acid region, while it notably increased with increasing pH in an alkaline region. The relative permittivity of the film changed 43.7-80.5 when the electrolyte pH was increased from 1.6 to 10. The incorporation depth and content of phosphorus in the film were markedly suppressed at pH 10, and nitrogen was found to penetrate into a depth of 70%. Furthermore, the apparent transport number of Nb⁵⁺ ion decreased from 0.26 to 0.02 by a pH increase from 1.6 to 10. The notable changes in structure and dielectric properties of the anodic niobia film formed in the alkaline region would primarily be caused by the different incorporation behavior of electrolyte species such as phosphorous and nitrogen.