Effects of limited proteolysis on functional properties of ovalbumin

We examined the limited proteolysis of ovalbumin by pepsin and its effect on the functional properties of the ovalbumin. Pepsin hydrolyzed only the single peptide bond of ovalbumin between His-22 and Ala-23. This provided a large intermediate (MW 42,500), P-ovalbumin. A P-ovalbumin solution gave a transparent gel when heated. Under the same conditions, an ovalbumin solution gave a turbid gel. We studied the physicochemical properties of P-ovalbumin and the formation of the transparent gel.     

FTIR study on structural transformation of keratin films induced by stretching

Fourier transform infrared spectroscopy (FTIR) was employed to explore the structural transformation by stretching of the film composed of a keratin derivative. The derivative was prepared by S-carboxymethylation of the low-sulfur keratin of wool. The cast film was stretched to different ratios in ethanol/water (7:3 v/v). The amide infrared absorption bands of the derivative were changed by stretching the film. Curve analysis was undertaken to estimate the contribution of each peptide conformation to the amide II band at each stretching. The analysis shows that the stretching mainly causes the structural transformation from random coil to β-structure. Moreover, a transient state arises in the course of the transformation. In such a state, the part of random coil increases while that of β-structure decreases. The infrared dichroism of the film also supports the existence of the transient state. On curve analysis, only the α-structure was found to reverse the dichroism of the amide II band in the transient state. This result suggests that the crystalline phase of α-structure is rearranged. Such rearrangement results in inhibition of the transformation from random coil to β-structure.     

Terrain adaptive detector selection for visual odometry in natural scenes

Pose estimation is one of the important tasks for mobile robots exploring in outdoor environments. Recently, visual odometry has received a lot of attention since its localization is accurate even with low-cost sensors. Furthermore, the technique is not affected by wheel slips, and it can be performed without external infrastructures and preliminary maps. While existing techniques successfully provide good localization of outdoor vehicles, possible failures are not yet fully examined in untextured terrains where feature tracking occasionally fails. This paper proposes an approach to detect interest points from a wide variety of terrains by adaptively selecting algorithms. Experiments show that the approach provides robust and fast interest point detection even in untextured natural scenes.     

Experimental verification of two-norm,infinity-norm continuous switching implemented in resolution of biarticular actuation redundancy

Utilization of redundancy endows systems with dexterity and fault tolerance in achieving its desired output, but its utilization implies added complication which must be resolved. Input optimization using the two-norm and the infinity-norm are two methods popularly utilized to address this problem. However, each resolution criteria finds its greatest benefit in opposite circumstances. This fact has long motivated a resolution system which makes use of both norms, switching back and forth when called for. In a previous publication, we introduced and proved the continuity of the first realization of such a switching resolution system, implemented in the resolution of biarticular actuation redundancy. In this work, we demonstrate the empirical validity and utility of the switching system through implementation in a developed robotic arm equipped with biarticular actuation redundancy. It is found that resolution allows for equivalent maximum torque requirements as the infinity-norm – an improvement over two-norm – but with improved electrical energy requirements over infinity-norm.     

Study on thermal decomposition characteristics of AIBN

It is found that the results such as observed in the differential scanning calorimeter (DSC), which show the major thermal decomposition (TD) of a self-reactive material, lack the detail to reveal what happens at the initial stage of a reaction. The reaction at this stage is corresponding to the handling condition of storage or transportation, often possibly having the potential to be developed to a runaway reaction. This paper examined and compared the thermal behaviors of AIBN at various working conditions in calorimeters and Dewar vessels. The mechanism that affects the initial reaction and self-heating behavior of the given material was clarified. Near its onset decomposition temperature, physical processes, such as sublimation or melting interfered the initial reaction of AIBN. The mutuality of the physical effect and the chemical reaction made AIBN behave differently under different measuring conditions, and as the result, quasi-autocatalysis or TD possibly occurs in the same sample at the handling temperature range. The heat accumulation storage tests in two Dewar vessels presented completely different self-heating behaviors due to this mechanism and heat transfer capability of the vessels.     

Risk evaluation on the basis of pressure rate measured by automatic pressure tracking adiabatic calorimeter

An automatic pressure tracking adiabatic calorimeter (APTAC) had been employed to obtain the thermokinetic and the vapor pressure data during runaway reactions. The APTAC is an adiabatic calorimeter with a large-scale sample mass and low thermal inertia, and is an extremely useful tool for assessing thermal hazards of reactive chemicals. The data obtained by the APTAC are important information for the design of the safe industrial process. The thermodynamics parameters and the gas production were discussed on the basis of the experimental data of various concentrations and weights of di-tert-butyl peroxide (DTBP)/toluene solution for the purpose of investigating the properties of the APTAC data. The thermal decomposition of DTBP was studied on the basis of the temperature data and the pressure data obtained by the APTAC. The activation energy and the frequency factor of DTBP are nearly constant and the same as the literature values in the concentrations between 20 and 60 wt.%. The pressure rise due to gas production is important data for designing the relief vent of a reactor. The time history of the gas production was investigated with various weights and concentrations. The total gas production index, which had the vapor pressure correction, was 1.0 in the decomposition of DTBP.     

Risk assessment on processing facility of raw organic garbage

To investigate the cause of an explosion during disposal processing of raw garbage, the property of the raw garbage was primarily examined by a thermo gravimetry-differential thermal analyzer. With mutable oil concentration, the results showed variable onset temperatures of the exothermal reaction for the samples, for example, decreasing from 150 degrees C in the samples typically containing 10.9-14.1% oil to 114 degrees C when the oil content was raised to 40%. The disposal process was then simulated in a laboratory-scale facility being heated by hot air of 150 degrees C, which was blown into the bottom through nozzles. In the case of the dried garbage containing 14.1% oil, white smoke emitted after several hours, accompanying with an abrupt rise of the temperatures in particular at the bottom of the facility. The maximum temperature reached to 1070 degrees C. Meanwhile, gases, including flammable ones, whose amounts were CO2 approximately CO>H2>methane>ethane in order, were yielded. It indicated that smoldering developed from the zones near the hot air supply nozzle and propagated along the pathway of the imposed air. The continuously released gases possibly induced the transition of smoldering to flame or explosion after accumulating for hours.     

Presence of activated B-1 cells in chronic inflamed gingival tissue

The oncology nurse's role in breast cancer management is enhanced by knowledge of the patient's perceptions of risks. This case study elucidates the process by which perceived risks of breast cancer are embedded in sequences of biographic experiences including childhood sexual abuse, childhood injuries, and an abusive marriage. The case study shows that risk perceptions and subsequent delayed breast cancer detection is related to (a) a belief that breast cancer results from "bad luck, or fate"; (b) lack of cancer-related symptoms; (c) belief that a higher power determines ill health; (d) reluctance to turn to others for help while in an abusive marriage; (e) family history of cancer invulnerability since generations of family members died of diabetes, heart disease, and pregnancy-related illnesses; and (f) fear of gynecologic exams resulting from childhood sexual abuse. Furthermore, nonapplicability of traditional breast cancer risk factors such as heredity, age older than 30 years at first full-term pregnancy, early menarche, and late menopause prohibit an accurate assessment of self-risk. This case study suggests that breast cancer risk perception often differs from that of biomedical factors, and that an understanding of risk judgments is essential for appropriate therapeutic responses.     

Mechano-Optical Sensors Fabricated with Multilayered Liquid Crystal Elastomers Exhibiting Tunable Deformation Recovery

Advances in tuning the mechanoresponsive behavior of liquid crystal elastomers have facilitated the development of next-generation applications such as reconfigurable photonic/electronic materials, energy-harvesting devices, and flexible sensors. However, the molecular-level control of mechanical responses remains difficult, with limited tunability achieved for recovery processes after stimulus removal. Herein, a design concept is proposed for facilely tuning the recovery of both the macroscopic deformation and molecular orientation change of liquid crystal elastomers using layered materials that exhibit the desired mechanoresponsive behavior. Changing the layering materials (a polydimethylsiloxane film with elastic response to a polymethylpenten film with plastic response) alters the relaxation time from <1 s to >6 months. To demonstrate this concept, highly sensitive, stretchable mechano-optical sensors with fast and ultraslow recovery times are developed that enable an applied strain to be quantitatively detected in real time or memorized with high spatial resolution, even with a conventional camera. This material design concept for arbitrarily controlling the recovery response can provide a platform for stimuli-responsive applications.