Studies on the subsite structure of amylases. III. Inhibition by gluconolactone of the hydrolysis of maltodextrin catalyzed by glucoamylase from Rhizopus niveus

Inhibition by gluconic acid-1 : 5-lactone (gluconolactone) and phenyl alpha-glucoside of the hydrolysis of maltodextrin catalyzed by glucoamylase [EC 3.2.1.3] from Rhizopus niveus was investigated in relation to the subsite structure of the enzyme. Inhibition by gluconolactone was of the mixed type, whereas that by phenyl alpha-glucoside was purely competitive. These inhibition types were consistent with a theoretical prediction based on the assumption that gluconolactone and phenyl alpha-glucoside bind mainly to Subsites 1 and 2, respectively. The inhibitor constant of gluconolatone was determined to be 1.5 mM, which is in good agreement with the dissociation constant estimated by difference spectrophotometry (1.5 mM) (Ohnishi, M, et al. (1975) J. Biochem, 77, 695-703).     

Evaluation of TEM samples of an Mg-Al alloy prepared using FIB milling at the operating voltages of 10 kV and 40 kV

Transmission electron microscopy (TEM) samples of an Mg-Al alloy has been prepared using a Ga-focused ion beam (FIB) milling at two different operating voltages of 10 kV and 40 kV to investigate the influence of the FIB energy on the sample quality. The fine structures of the samples have been studied using a high resolution TEM, and the concentration of the implanted Ga was analysed using an energy dispersive X-ray (EDX) analysis. The result of the TEM observation revealed that point defects were introduced to the sample finally milled at 40 kV but not at 10 kV. However, crystal lattice images and electron diffraction patterns were clearly observed on both the samples. The typical influence of the FIB energy was indicated in the elemental analysis. The relative Ga concentration in the thin sample finally milled at 10 kV was 1.0-2.0 at% that is less than half of 4.0-6.0 at% of the Ga concentration in the sample finally milled at 40 kV. A comparison between the experimental results of the Ga concentration measurement with simulation was also discussed.     

Heart instantaneous frequency (HIF): an alternative approach to extract heart rate variability

Our study focuses on a new method of estimating the heart rate variability (HRV) which does not require the use of electrocardiogram (ECG) R-wave detection. Contrary to the R-wave detection method which requires a sampling frequency higher than 100 Hz, the one proposed here can be used to calculate the HRV from an ECG signal sampled at a frequency of approximately 5 Hz with a relative mean error of 0.03. This new method is based on extracting the instantaneous fundamental frequency from the ECG. The method could be efficiently used to extract the HRV from an ECG measured for healthy subjects performing an exercise in which the HRV increases linearly with time, and for subjects with respiratory and cardiac problems. The overall error decreased as we low-pass filtered the HRV with lower cut-off frequencies. Moreover, it was shown that the method could be efficiently used to calculate the HRV from blood pressure measurements and to be robust to noise.     

Multirate Sampling Method for Acceleration Control System

This paper focuses on the realization of high-performance motion control based on acceleration control. A disturbance observer is used to construct an acceleration control system. A high sampling frequency is known to be effective for improving the performance. Characteristics of acceleration control are investigated to discuss the relationship between the performance and a sampling frequency of the system. The needs for a high sampling frequency for an output are then described. Based on these considerations, a novel multirate sampling method for the acceleration control system is proposed. An output sampling period is set shorter than an input sampling period, and control calculation is executed at each output sampling period in the method. The disturbance observer is redesigned for application to the multirate system. Stability analysis is performed to verify the validity of the proposal. Feasibility of the proposed method and its influence on the performance are also verified by experimental results     

Transmission of Force Sensation by Environment Quarrier Based on Multilateral Control

In recent years, realization of a haptic system has been strongly desired in the fields of medical treatment and expert's skill acquisition. The bandwidth of force sensing and friction compensation are very important problems for reproduction of vivid force sensation. In this paper, an environment quarrier is proposed for bilateral teleoperation instead of force sensors. The environment quarrier is a novel force-sensing method that consists of a twin robot system. Two of the same type of robot are required and they are controlled in the same position, velocity, and acceleration by bilateral acceleration control based on a disturbance observer. One robot is in contact motion and the other is unconstrained. The purity of external force is obtained by subtracting the disturbance torque in the unconstrained robot from the constrained one. The environment quarrier can observe the external force with high bandwidth and friction compensation. In this paper, the idea of multilateral control is introduced for attainment of simultaneity. Furthermore, this paper shows the controller design of the multilateral control in the modal space. The experimental results show the viability of the proposed method     

Informative patches sampling for image classification by utilizing bottom-up and top-down information

In image classification based on bag of visual words framework, image patches used for creating image representations affect the classification performance significantly. However, currently, patches are sampled mainly based on processing low-level image information or just extracted regularly or randomly. These methods are not effective, because patches extracted through these approaches are not necessarily discriminative for image categorization. In this paper, we propose to utilize both bottom-up information through processing low-level image information and top-down information through exploring statistical properties of training image grids to extract image patches. In the proposed work, an input image is divided into regular grids, each of which is evaluated based on its bottom-up information and/or top-down information. Subsequently, every grid is assigned a saliency value based on its evaluation result, so that a saliency map can be created for the image. Finally, patch sampling from the input image is performed on the basis of the obtained saliency map. Furthermore, we propose a method to fuse these two kinds of information. The proposed methods are evaluated on both object categories and scene categories. Experiment results demonstrate their effectiveness.     

Fabrication of vertically aligned single-walled carbon nanotubes in atmospheric pressure non-thermal plasma CVD

A fabrication technique of high-purity vertically aligned single-walled carbon nanotubes (VA-SWCNTs) using atmospheric pressure plasma enhanced chemical vapor deposition is presented. Although densely mono-dispersed Fe-Co catalysts of a few nanometers is primarily responsible for VA-SWCNT growth, carbon precipitation was virtually absent in the thermal CVD regime at 700 °C. On the other hand, high-purity VA-SWCNTs without measurable defects were grown at 4 μm min⁻¹ by applying atmospheric pressure radio-frequency discharge (APRFD) which has been previously developed for this purpose. The results proved that cathodic ion sheath adjacent to the substrates, where a large potential drop exists, also plays an essential role for the controlled growth of SWCNTs, while ion damage to the VA-SWCNTs is inherently avoided due to high collision frequency among molecules in atmospheric pressure. Operation regime of APRFD and tentative reaction mechanisms for VA-SWCNT growth are discussed along with optical emission spectroscopy of near substrate region.