This paper focuses on the teleoperation of a robot hand on the basis of finger position recognition and grasp type estimation. For the finger position recognition, we propose a new method that fuses ...machine learning and high-speed image-processing techniques. Furthermore, we propose a grasp type estimation method according to the results of the finger position recognition by using decision tree. We developed a teleoperation system with high speed and high responsiveness according to the results of the finger position recognition and grasp type estimation. By using the proposed method and system, we achieved teleoperation of a high-speed robot hand. In particular, we achieved teleoperated robot hand control beyond the speed of human hand motion.
The present study deals with the basins of the equilibrium points embedded within the normal forms of Bogdanov–Takens bifurcation with delayed feedback control. It is numerically shown that the ...unstable periodic orbit that coexists with the equilibrium point stabilized by delayed feedback control is associated with the basin of the stabilized point. The relation between the periodic orbit and the basin indicates that for enlarging the basin, a homoclinic bifurcation for the orbit and a saddle point can provide useful information for the design of delayed feedback controllers. These results are experimentally confirmed in a real direct-current bus circuit that has dynamics similar to that of the normal form .
This paper describes repeatable detection of Ag
ions using a DNA aptamer-linked hydrogel biochemical sensor integrated with a microfluidic heating system. Biochemical sensors that respond to chemical ...compounds and produce detectable signals have a critical role in many aspects of modern society. In particular, the repeatable measurement of environmental information such as toxic substances including Ag
ions could be expected to improve the environment. The DNA aptamer is an attractive candidate because of the stability and the selectivity of binding to chemicals. However, previous DNA aptamer biochemical sensors could not measure repeatedly because those sensors did not have initializing functions. To overcome this challenge, we proposed a DNA aptamer-linked hydrogel biochemical sensor integrated with the microfluidic heating system enabling repeatable detection of Ag
ions. The binding Ag
ions are dissociated by heating and flushing through the integrated microfluidic heating device. The DNA aptamer-linked hydrogel had the capability to detect a wide range of Ag
ion concentrations (10
-10 mM) including a toxic range for various aquatic organisms. Finally, we demonstrated the repeatable detection of the Ag
ions. These results indicated that our proposed biochemical sensor is expected to use for long-term monitoring with high stability in ambient temperature and low power consumption.
In nature, most microorganisms have motility, which is essential for their survival or reproduction. To move, some microorganisms have evolved soft spiral‐shaped flagella, which rotate through ...specialized motors. Many of these microorganisms can change the morphology of their spiral‐shaped flagella to control their motility. Herein, by mimicking these flagella, spiral‐shaped microswimmers are developed for various applications, such as target drug delivery, micro‐object transport, and micro‐fluid manipulation. In previous studies, numerous fabrication methods of spiral‐shaped microswimmers are developed. However, the swimming direction and velocity are controlled only by external systems, such as magnetic fields, because the spiral body is not able to deform. Therefore, this soft spiral‐shaped microswimmer for autonomous swimming control by detecting surrounding stimuli is proposed. The velocity of microswimmer largely depends on the geometry of the microswimmer's body. Through usage of a stimuli‐responsive hydrogel in the microswimmer, the geometry autonomously changes in response to the surrounding stimuli. Using finite‐element simulation, it is revealed that the pattern angle is an important parameter for acceleration/deceleration of the microswimmer. The dimensionless velocity of the fabricated bilayered spiral swimmer changes by deforming the geometry in response to the surrounding thermal stimuli.
A soft spiral‐shaped microswimmer for autonomous swimming control by detecting surrounding environments is proposed. By applying the stimuli‐responsive hydrogel to the microswimmer, the geometry of the microswimmer's body autonomously changes in response to the surrounding stimuli. By deforming the geometry, the dimensionless velocity of the spiral swimmer successfully changes.
Abstract The aim of this study was to determine whether histone deacetylase inhibitors (HDACi), including entinostat (MS-275), valproic acid (VPA), trichostatin A (TSA), and sodium butyrate (NaB), ...promoted the odontogenic differentiation of the odontoblast-like cell line, MDPC-23 in the absence of an osteoblast mineralization medium. The cells were cultured in basal medium (Dulbecco's modified Eagle medium) with and without (controls) the inhibitors. The cell viability and migration were assessed using the cell proliferation reagent WST-1 and a scratch wound healing assay, respectively. The mRNA expression levels of bone morphogenetic protein (Bmp)-2 and -4, collagen 1 alpha 1 (Col1α1), osteocalcin (Oc), dentin matrix protein 1 (Dmp1), dentin sialophosphoprotein (Dspp), runt-related transcription factor 2 (Runx2), Krueppel-like factor 5 (Klf5), and Msh homeobox 1 (Msx1) were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Alizarin red and alkaline phosphatase assays were performed to determine the extent of mineralization in the culture systems. No significant differences in cell numbers were observed between the controls and the MS-275-, VPA-, and NaB-treated cells; however, a significant difference was observed with TSA (concentration, 1000 nM). The scratch wound healing assay showed no effect of cell migration in the MS-275 (1.0 μM)-treated cells when compared with the controls at 24 h. Furthermore, MS-275, VPA, and NaB increased the mRNA expression levels of Bmp-2 and -4, Oc, and Runx2 followed by the mineralization of the cells. Only MS-275 significantly increased the expression levels of Dmp1, Dspp, Klf5, and Msx1 in the cells. These findings indicated that MS-275 may be considered as a reliable candidate for the odontogenic differentiation of dental pulp cells.
In nature, some insects can rapidly propel by using the Marangoni effect without employing the oscillatory movements of legs. Inspired by nature's Marangoni‐propulsion principles, various ...Marangoni‐propulsion untethered micro‐robots are achieved to propel with small energy storage. For practical use of Marangoni‐propulsion micro‐robots, it is required to have the intelligence to detect the external environment. However, previous Marangoni‐propulsion micro‐robots integrated with wireless micro‐scale sensors that can sense the external environment and transmit the obtained information are not achieved. Herein, Marangoni propulsion micro‐robots integrated with a wireless photonic gel sensor for exploring the aquatic environment and transmitting the environmental information are proposed. The proposed micro‐robots can propel at the water–air interface by the Marangoni effect. The integrated photonic gel sensor can sense the external stimuli and transmit the information by the color change. In this research, the responsivity of the micro‐robots is evaluated by the propulsion velocity and the response time of the photonic gel. It is shown that the propulsion velocity is changed by the outlet area. The response time decreased as the diameter of the photonic gel decreased. Finally, it is demonstrated that the photonic gel sensor can dynamically sense the external stimuli while the micro‐robots propel.
One of the grand challenges of untethered micro‐robots is the integration of wireless sensors. Herein, Marangoni‐propulsion micro‐robots integrated with a wireless photonic gel sensor for exploring the aquatic environment are proposed. The proposed photonic gel sensor can dynamically sense the environmental stimuli and transmit the obtained information by the color change while the micro‐robots propel by the Marangoni effect.
The epithelial cell rests of Malassez (ERM) are essential in preventing ankylosis between the alveolar bone and the tooth (dentoalveolar ankylosis). Despite extensive research, the mechanism by which ...ERM cells suppress ankylosis remains uncertain; perhaps its varied population is to reason. Therefore, in this study, eighteen unique clones of ERM (CRUDE) were isolated using the single-cell limiting dilution and designated as ERM 1-18. qRT-PCR, ELISA, and western blot analyses revealed that ERM-2 and -3 had the highest and lowest amelogenin expression, respectively. Mineralization of human periodontal ligament fibroblasts (HPDLF) was reduced in vitro co-culture with CRUDE ERM, ERM-2, and -3 cells, but recovered when an anti-amelogenin antibody was introduced. Transplanted rat molars grown in ERM-2 cell supernatants produced substantially less bone than those cultured in other cell supernatants; inhibition was rescued when an anti-amelogenin antibody was added to the supernatants. Anti-Osterix antibody staining was used to confirm the development of new bones. In addition, next-generation sequencing (NGS) data were analysed to discover genes related to the distinct roles of CRUDE ERM, ERM-2, and ERM-3. According to this study, amelogenin produced by ERM cells helps to prevent dentoalveolar ankylosis and maintain periodontal ligament (PDL) space, depending on their clonal diversity.
The DNA demethylating agent, 5-Azacytidine (5Aza), and histone deacetylase inhibitor, valproic acid (Vpa), can improve the reprogramming efficiencies of pluripotent cells. This study aimed to examine ...the roles of 5Aza and Vpa in the dedifferentiation of epithelial cell rests of Malassez (ERM) into stem-like cells. Additionally, the ability of stem-like cells to differentiate into mesenchymal cells was evaluated. ERM was cultured in embryonic stem cell medium (ESCM) with 1 µM of 5Aza, or 2 mM of Vpa, or a combination of 5Aza and Vpa. The cells stimulated with both 5Aza and Vpa were named as progenitor-dedifferentiated into stem-like cells (Pro-DSLCs). The Pro-DSLCs cultured in ESCM alone for another week were named as DSLCs. The stem cell markers were significantly higher in the DSLCs than the controls (no additions). The mRNA and protein levels of the endothelial, mesenchymal stem, and osteogenic cell markers were significantly higher in the Pro-DSLCs and DSLCs than the controls. The combination of a demethylating agent and a deacetylated inhibitor induced the dedifferentiation of ERM into DSLCs. The Pro-DSLCs derived from ERM can be directly reprogrammed into mesenchymal-like cells without dedifferentiation into stem-like cells. Isolated ERM treated with epigenetic agents may be used for periodontal regeneration.
Abstract Gut dysbiosis induces 'leaky gut,' a condition associated with diabetes, NASH, and various auto-immune diseases. Porphyromonas gingivalis is a periodontopathic bacterium which causes ...periodontal tissue breakdown, and often enters the systemic blood flow. Oral administration of P.gingivalis induced gut dysbiosis in mice model, but no systemic administration of P.gingivalis has been reported thus far. In the present study, we investigated the effect of P.gingivalis-derived lipopolysaccharide (Pg-LPS) on the intestinal flora of our established mouse model. Eight-week-old C57BL/6J mice were intraperitoneally administered Pg-LPS. Three months later, DNA was extracted from stool, and RNA from the small and large intestines. After euthanizing the mice, pathological sections of the intestinal tract were prepared and stained with hematoxylin and eosin (H&E). Tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 expression levels were evaluated using quantitative PCR. 16S rRNA gene PCR amplicon analysis data were acquired using NGS. Microbial diversity and composition were analyzed using Quantitative Insights into Microbial Ecology 2. Furthermore, alterations in microbial function were performed by PICRUSt2. No significant inflammatory changes were observed in the H&E. No significant differences in the mRNA levels of IL-1β, IL-6, and TNF-α were observed between the groups. Pg-LPS administration decreased the abundance of Allobacterium in the gut. A predictive metagenomic analysis by PICRUSt2 and STAMP showed that 47 pathways increased and 17 pathways decreased after Pg-LPS administration. Systemic application of periodontal pathogens may cause changes in the intestinal flora which may affect the physiological functions of the intestinal tract.
We propose a method of supercontinuum light generation enhanced by multimode excitation in a precisely dispersion-engineered deuterated SiN (SiN:D) waveguide. Although a regularly designed SiN-based ...nonlinear optical waveguide exhibits anomalous dispersion with the fundamental and first-order multimode operation, the center-symmetric light pumping at the input edge has so far inhibited the full potential of the nonlinearity of SiN-based materials. On the basis of numerical analysis and simulation for the SiN:D waveguide, we intentionally applied spatial position offsets to excite the fundamental and higher-order modes to realize bandwidth broadening with flatness. Using this method, we achieved an SNR improvement of up to 18 dB at a wavelength of 0.6 µm with an offset of about 1 µm in the Y-axis direction and found that the contribution was related to the presence of dispersive waves due to the excitation of TE
, and TE
modes.
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