A multi-walled carbon nanotube/polymer actuator that surpasses the performance of a single-walled carbon nanotube/polymer actuator

Actuators were developed using activated and non-activated multi-walled carbon nanotube (MWCNT)–ionic liquid (IL) gel electrodes and compared to a single-walled carbon nanotube (SWCNT)-based actuator with respect to the electrochemical and electromechanical properties. The activated MWCNT–COOH/polymer actuator surpassed the SWCNT/polymer actuator in terms of the generated strain.     

Memory-efficient 3D connected component labeling with parallel computing

Connected component labeling is a frequently used image processing task in many applications. Moreover, in recent years, the use of 3D image data has become widespread, for instance, in 3D X-ray computed tomography and magnetic resonance imaging. However, because ordinary labeling algorithms use a large amount of memory and 3D images are generally large, labeling 3D image data can cause memory shortages. Furthermore, labeling a large image is time-consuming. In this paper, we proposed new memory-efficient connected component labeling algorithm for 3D images with parallel computing. In this method, we accelerate the labeling process using parallel computing. In addition, we use a spans matrix and compressed label matrix to reduce memory usage. We also use an equivalence chain approach to speed up the calculation. Furthermore, the algorithm has two options for further processing performance or further memory savings. In the experiments on real examples, the proposed algorithm with the option for processing speed was faster and used less memory than the conventional label equivalence method. In contrast, with the proposed method using the memory-efficient option, we could further reduce memory from one-eighth to one-thirteenth that used by the label equivalence method while maintaining the same performance.     

Quadruped virtual robot simulation in a virtual environment obeying physical laws

In the development of a robot, the validation of that robot with the use of real machinery takes a considerable amount of time and money. In particular, it is difficult to validate a robot’s behavior in an unsafe place. The developers also have to pay attention to virtual debugging. Using a program validated in VR space makes the verification of a real machine’s behavior more efficient. In this research, we make a virtual robot walk on a road autonomously by using a program where the virtual robot tracks a line in a virtual environment.     

Development of an inheritance assist system for experiencing operation skills by using a haptic function of PHANToM

At present, several commercially available surgical simulators have been used in advanced medical facilities, and most of them provide a self-learning environment for trainees who are young doctors and/or residents. Therefore, we assume that inexperienced doctors have to inherit the veteran skills of experienced doctors because the lack of doctors and nurses is one of the most serious medical issues. This article proposes a training function on a surgical simulator system which enables trainees to sense the feelings of experienced surgeons while operating. The inheritance assistance function we are constructing might be of help in compensating for the lack of experience of young doctors and be more effective than the present system. The inheritance assistance function makes it possible to record the operational data of experienced doctors, and to reproduce this data in a training scene for young trainees. Then young doctors could practice their own skills by intuitively referencing the recorded advisory data in a surgical simulator. In order to accomplish the purpose of this study, we have constructed a fundamental system. A simple virtual object based on a dynamic model reacts in terms of visualization and force against the manipulation of virtual forceps via a haptic device, PHANToM. Several laboratory students of the experimental subject were challenged to obtain training with the system developed. This article describes the system and discusses the results and future work.     

Motility and the expression of the flagellin protein FliC are negatively regulated by quorum sensing in Edwardsiella tarda

Edwardsiella tarda is a gram-negative bacterial pathogen of fish and animals. A number of gram-negative bacteria have quorum-sensing systems and produce N-acylhomoserine lactone (AHL) that they use as a quorum-sensing signaling molecule. We have already reported that E. tarda NUF251 produces AHLs and has the AHL-synthase gene, edwI. Inactivation of NUF251 edwI induces expression of an approximately 45 kDa extracellular protein, identified as a flagellin encoded by FliC. Mutation of edwI also changes the motility pattern of NUF251 from a radial expansion pattern to concentric rings. The addition of exogenous AHL was capable of restoring normal motility to NUF251 edwI mutants. These results demonstrate that quorum sensing negatively regulates motility and expression of the FliC protein.     

Modeling and deforming a virtual dense elastic object with the haptic device PHANToM

In recent years, there have been various problems in medical treatments, of which human error by the surgeon in an operation is one of the most serious. In order to minimize human error in an operation, we need a medical training system by which inexperienced surgeons can try operating again and again to improve their skill. In this research, we construct a system of modeling a virtual dense elastic object, and deforming that object using a haptic device called PHANToM. In the system which we construct, we use two PCs to distribute the process of calculation, and SCRAMNet+ is used to connect each PC. PHANToM is used to operate on the object and to express the force which is generated from the deformation of the object. We represent the dense object by using voxels and tetrahedrons, and the elastic object by using a spring-mass model. A virtual dense elastic object is obtained by computed tomography (CT) or magnetic resonance imaging (MRI) to express the patient’s organs.     

Surface photocrosslinking of ethylene–vinyl acetate copolymer films

Surface photocrosslinking of ethylene–vinyl acetate (EVAc) copolymer films containing benzophenone (BP) was investigated for the purpose of replacing a poly(vinyl chloride) floor. The photogelatin in the EVAc films was effectively observed after UV radiation in the presence of oxygen. The crosslinking reaction was initiated from the surface of the irradiated film, which was mainly due to the dehydrogenation and generation of macroradicals of polymer by the light absorption of BP. The experiments of polyethylene–VAc with BP showed that the VAc‐rich amorphous part in the EVAc copolymer works as a crosslinking site. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1741–1745, 2000     

Acid-treated high-amylose corn starch suppresses high-fat diet-induced steatosis

Resistant starch (RS) has been reported to improve steatosis as well as obesity. Type 4 resistant starch (RS4), a chemically modified starch, is particularly hard to digest and suggesting higher efficacy. However, because the effects of RS4 on steatosis are not yet fully understood, the effects of RS4 on steatosis were examined using a murine high-fat diet model. Seven-week-old male mice were divided into three groups and fed a normal diet, a high-fat diet (HFD), or a high-fat diet with added RS (HFD + RS). Amylofiber SH^® produced from acid-treated corn starch was used as the dietary RS. At 22 weeks old, hepatic steatosis and short chain fatty acid (SCFA) content and gut microbiota in cecum stool samples were analyzed. The ratio of body weight to 7 weeks was significantly suppressed in the HFD + RS group compared to the HFD group (132.2 ± 1.4% vs. 167.2 ± 3.9%, p = 0.0076). Macroscopic and microscopic steatosis was also suppressed in the HFD + RS group. Analysis of cecum stool samples revealed elevated SCFA levels in the HFD + RS group compared with the HFD group. Metagenome analysis revealed that Bifidobacterium (17.9 ± 1.9% vs. 3.6 ± 0.7%, p = 0.0019) and Lactobacillus (14.8 ± 3.4% vs. 0.72 ± 0.23%, p = 0.0045), which degrade RS to SCFA, were more prevalent in the HFD + RS group than the HFD group. In conclusion, RS4 suppressed steatosis, and increased Bifidobacterium and Lactobacillus, and SCFAs. RS4 may prevent steatosis by modulating the intestinal environment.     

Toward in vivo imaging of heart disease using a radiolabeled single-chain Fv fragment targeting tenascin-C

Antibodies specific to a particular target molecule can be used as analytical reagents, not only for in vitro immunoassays but also for noninvasive in vivo imaging, e.g., immunoscintigraphies. In the latter case, it is important to reduce the size of antibody molecules in order to achieve suitable in vivo "diagnostic kinetics" and generate higher-resolution images. For these purposes, single-chain Fv fragments (scFvs; M(r) < 30 kDa) have greater potential than intact immunoglobulins (~150 kDa) or Fab (or Fab') fragments (~50 kDa). Our recent observation of enhanced tenascin-C (Tnc) expression at sites of cardiac repair after myocardial infarction prompted us to develop a radiolabeled scFv against Tnc for in vivo imaging of heart disease. We cloned the genes encoding the heavy and light chain variable domains of the mouse anti-Tnc monoclonal antibody 4F10, and combined them to create a single gene. The resulting scFv-4F10 gene was expressed in E. coli cells to produce soluble scFv proteins. scFv-4F10 has an affinity for Tnc (K(a) = 3.5 × 10(7) M(-1)), similar to the Fab fragment of antibody 4F10 (K(a) = 1.3 × 10(7) M(-1)) and high enough to be of practical use. A cysteine residue was then added to the C-terminus to achieve site-specific (111)In labeling via a chelating group. The resulting (111)In-labeled scFv was administered to a rat model of acute myocardial infarction. Biodistribution and quantitative autoradiographic studies indicated higher uptake of the radioactivity at the infarcted myocardium than the noninfarcted one. Single photon emission computed tomography (SPECT) provided in vivo cardiac images that coincided with the ex vivo observations. Our results will promote advances in diagnostic strategies for heart disease.