This paper proposes an adaptive neural impedance control (ANIC) strategy for electrically driven robotic systems, considering system uncertainties and external disturbances. For the considered ...robotic system, the joint velocities and armature currents are assumed to be unknown and unmeasured, and an adaptive observer is then designed to estimate its unknown states using a neural network. Based on the observed joint velocities and armature currents, an ANIC scheme is proposed and the performances of the joint positions and force tracking can be improved. We also prove that the control system is stable and all the signals in closed-loop system are bounded. Simulation examples on a two-link electrically driven robotic manipulator are presented to show the effectiveness of the proposed observer-based intelligent impedance control method.
A layer-by-layer self-assembled nitrogen-doped graphene/PDDA/gold nanoparticle (NDG/PDDA/GNP) composite was described. Citrate-stabilizing gold nanoparticle colloids (GNPs) were electrostatically ...adsorbed onto NDG nanosheets using a cationic polyelectrolyte, polydiallyldimethylammonium (PDDA), as the linker, thereby creating a high-performance electrochemical interface. The morphology and chemical composition were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, infrared spectroscopy, and Raman spectroscopy. Analytical application was manifested by electrochemical sensing of uric acid (UA), a biomarker involved with a variety of clinical diseases. The prepared nanocomposite exhibited noticeable electroactivity to uric acid oxidation and can give effective peak separation with ascorbic acid and dopamine. Additionally, the nanocomposite practically averted from other potentially interferents including glucose, urea, and serotonin, thus allowing selective voltammetric detection of UA in the biological matrix. Under the optimal condition, peak currents measured by differential pulse voltammetry were proportional to UA concentrations in the range of 0.5~100 μM (
R
2
= 0.998), with the detection limit of 53 nM. The NDG/PDDA/GNP nanocomposite as presented herein holds potential for aiding the diagnosis of UA-associated diseases and should be a new opportunity for biochemical analysis and biosensing applications.
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In this paper, an adaptive Jacobian and neural network based position/force tracking impedance control scheme is proposed for controlling robotic systems with uncertainties and external disturbances. ...To achieve precise force control performance indirectly by using the position tracking, the control scheme is divided into two parts: the outer-loop force impedance control and the inner-loop position tracking control. In the outer-loop, an improved impedance controller, which combines the traditional impedance relationship with the PID-like scheme, is designed to eliminate the force tracking error quickly and to reduce the force overshoot effectively. In this way, the satisfied force tracking performance can be achieved when the manipulator contacts with environment. In the inner-loop, an adaptive Jacobian method is proposed to estimate the velocities and interaction torques of the end-effector due to the system kinematical uncertainties, and the system dynamical uncertainties and the uncertain term of adaptive Jacobian are compensated by an adaptive radial basis function neural network (RBFNN). Then, a robust term is designed to compensate the external disturbances and the approximation errors of RBFNN. In this way, the command position trajectories generated from the outer-loop force impedance controller can be then tracked so that the contact force tracking performance can be achieved indirectly in the forced direction. Based on the Lyapunov stability theorem, it is proved that all the signals in closed-loop system are bounded and the position and velocity errors are asymptotic convergence to zero. Finally, the validity of the control scheme is shown by computer simulation on a two-link robotic manipulator.
Microwave ablation (MWA) is a potent cancer treatment tool, but its effectiveness can be hindered by the lack of visual feedback. This paper validates the feasibility of using microwave-induced ...thermoacoustic imaging (TAI) technique to monitor the MWA process. A feasibility analysis was conducted at the principle level and a high-performance real-time TAI system was introduced. To address the interference caused by MWA, a robust principal component analysis (RPCA)-based method for TAI was proposed. This method leverages the correlation between multiple signal frames to eliminate interference. RPCA’s effectiveness in TAI was demonstrated through three sets of different experiments. Experiments demonstrated that TAI can effectively monitors the MWA process. This work represents the first application of RPCA-related matrix decomposition methods in TAI, paving the way for the application of TAI in more complex clinical scenarios. By providing rapid and accurate visual feedback, this research advances MWA technology.
According to traditional Chinese medicine theory, tongue coatings reflect changes in the body. The goal of this study was to identify a metabolite or a set of metabolites capable of classifying ...characteristics of traditional Chinese medicine syndromes in erosive gastritis. In this study, we collected tongue coatings of patients with erosive gastritis with damp-heat syndrome (DHS), liver depression and qi stagnation syndrome (LDQSS), and healthy volunteers. Then, we analyzed the differences in metabolic characteristics between the two groups based on metabolomics. We identified 14 potential biomarkers related to the DHS group, and six metabolic pathways were enriched. The differential pathways included pyrimidine metabolism, pantothenate and CoA biosynthesis, citrate cycle (TCA cycle), pyruvate metabolism, glycolysis/gluconeogenesis, and purine metabolism. Similarly, in the LDQSS group, we identified 25 potential biomarkers and 18 metabolic pathways were enriched. The top five pathways were the TCA cycle, sphingolipid metabolism, fatty acid biosynthesis, pantothenate and CoA biosynthesis, and the pentose phosphate pathway. In conclusion, the DHS group and the LDQSS group have different characteristics.
Hua-Zhuo-Jie-Du (HZJD), a Chinese herbal prescription consisting of 11 herbs, is commonly used in China to treat chronic atrophic gastritis (CAG). We aimed to determine the effect of HZJD on the ...microbiome-associated metabolic changes in CAG rats.
The CAG rat models were induced by 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) combined with irregular fasting and 2% sodium salicylate, which was intragastrically administrated in fasted animals for 24 weeks. The CAG rats in the Chinese medicine (CM) group were administered a daily dose of 14.81 g/kg/day HZJD, and the vitacoenzyme (V) group were administered a daily dose of 0.08 g/kg/day vitacoenzyme. All animals were treated for 10 consecutive weeks, consecutively. Hematoxylin and eosin (H&E) staining was used to assess the histopathological changes in the gastric tissues. An integrated approach based on liquid chromatograph mass spectrometer (LC-MS) metabolic profiling combined with 16S rRNA gene sequencing was carried out to assess the effects of HZJD on CAG rats. Spearman analysis was used to calculate the correlation coefficient between the different intestinal microbiota and the metabolites.
The H&E results indicated that HZJD could improve the pathological condition of CAG rats. The LC-MS results indicated that HZJD could significantly improve 21 gastric mucosal tissue perturbed metabolites in CAG rats; the affected metabolites were found to be involved in multiple metabolic pathways, such as the central carbon metabolism in cancer. The results of 16S rRNA gene sequencing indicated that HZJD could regulate the diversity, microbial composition, and abundance of the intestinal microbiota of CAG rats. Following HZJD treatment, the relative abundance of Turicibacter was increased, and the relative abundance of Desulfococcus and Escherichia were decreased in the CM group when compared with the M group. Spearman analysis revealed that perturbed intestinal microbes had a strong correlation with differential metabolites, Escherichia exhibited a negative correlation with l-Leucine, Turicibacter was negatively correlated with urea, and Desulfococcus exhibited a positive correlation with trimethylamine, and a negative correlation with choline.
HZJD could protect CAG by regulating intestinal microbiota and its metabolites.
•A nonlinear observer is designed to estimate the joint velocities of the manipulator.•An ANNFTIC based on nonlinear observer is proposed to control the uncertain robotic system.•The proposed control ...method demonstrated the effective control performance on positions and force tracking for the robotic manipulator.
In this paper, an adaptive neural network force tracking impedance control scheme based on a nonlinear observer is proposed to control robotic system with uncertainties and external disturbances. It is supposed that the joint positions and interaction force of the robotic system can be measured, while the joint velocities are unknown and unmeasured. Then, a nonlinear velocity observer is designed to estimate the joint velocities of the manipulator, and the stability of the observer is analyzed using the Lyapunov stability theory. Based on the estimated joint velocities, an adaptive radial basis function neural network (RBFNN) impedance controller is developed to track the desired contact force of the end-effector and the desired trajectories of the manipulator, where the adaptive RBFNN is used to compensate the system uncertainties so that the accuracy of the joint positions and force tracking can be then improved. Based on the Lyapunov stability theorem, it is proved that the proposed adaptive RBFNN impedance control system is stable and the signals in closed-loop system are all bounded. Finally, simulation examples on a two-link robotic manipulator are presented to show the efficiency of the proposed method.
Huazhuojiedu decoction, a Chinese herbal preparation, has been proven to be clinically effective in treating precancerous lesions in gastric cancer (PLGC). This formula is optimized from a classic ...formula called “Ganluxiaodu Dan.” Although some experiments have shown that Huazhuojiedu decoction is effective against PLGC, the mechanism remains unclear.
To investigate the treatment of PLGC with Huazhuojiedu decoction from the perspective of lncRNA in vitro and in vivo.
A PLGC rat model was prepared and randomly divided into a Huazhuojiedu decoction group (HG), a vitacoenzyme group (VG), a model group (MG), and a normal group (CG). Each group was given a corresponding concentration of medicine and distilled water for 10 weeks. The pathological changes in the gastric mucosa were observed by hematoxylin-eosin staining (HE). High-throughput sequencing was performed to detect the differentially expressed lncRNAs in the HG, MG, and CG. Quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR) was used to verify differentially expressed lncRNAs, and rat–human homology information was obtained from the University of California, Santa Cruz (UCSC) Genome Database. Human gastric mucosal epithelial cells (GES-1) were used to prepare precancerous lesions of gastric cancer cells (MC). A Huazhuojiedu decoction drug-containing serum was prepared to treat the MC cells. The effects of the Huazhuojiedu decoction and the lncRNA ENST00000517368 (lnc 517368) knockdown or overexpression on PLGC cell proliferation and apoptosis were evaluated in vitro using CCK-8, flow cytometry, and RT-qPCR.
The HE results showed that gastric mucosal pathology was significantly improved in the HG. High-throughput sequencing results showed that compared with the CG, 91 lncRNAs upregulated in the MG were restored and downregulated in the HG (P < 0.05), and 115 lncRNAs downregulated in the MG were restored and upregulated in the HG (P < 0.05). The results of RT-qPCR were consistent with the sequencing results. The differentially expressed genomic rat lncRNA ENSRNOT00000079699 is homologous to human lnc 517368. In cell experiments, high expression of lnc 517368 promoted proliferation and reduced apoptosis in PLGC cells, while the Huazhuojiedu decoction reduced the expression of lnc 517368 and improved cell morphology.
Huazhuojiedu decoction inhibited cell proliferation and promoted apoptosis in PLGC cells, and its effect may be partially dependent on the downregulation of lnc 517368.
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Abstract Background When applied to thermoacoustic imaging (TAI), the delay‐and‐sum (DAS) algorithm produces strong sidelobes due to its disadvantages of uniform aperture weighting. As a result, the ...quality of TAI images recovered by DAS is often severely degraded by strong non‐coherent clutter, which restricts the development and application of TAI. Purpose To address this issue, we propose an adaptive complementary neighboring sub‐aperture (NSA) beamforming algorithm for TAI. Methods In NSA, we introduce a coordinate system transformation when calculating the normalized cross‐correlation (NCC) matrix. This approach enables the computation of the NCC coefficient within the specified kernel without complex coordinate calculations. We first conducted the numerical simulation experiment to validate NSA using a tree branch phantom. In addition, we also conducted phantom (five sauce tubes), ex vivo (ablation needle in ex vivo porcine liver), and in vivo (human arm) TAI experiments using our TAI system with a center frequency of 3 GHz. Results In the numerical simulation experiment, the structural similarity index (SSIM) value for NSA is increased from 0.37828 for DAS to 0.75492. In the point target phantom TAI experiment, the generalized contrast‐to‐noise ratio (gCNR) value for NSA is increased from 0.936 for DAS to 0.962. The experimental results show that NSA can recover clearer thermoacoustic images compared to DAS. In the ex vivo TAI experiment, the full width at half maxima (FWHM) of an ablation needle (diameter = 1.5 mm) for coherence factor (CF) weighted DAS and NSA are 0.9 and 1.3 mm, respectively. Furthermore, in the in vivo TAI experiment, CF reduces the signals within the arm compared to NSA. Therefore, compared with CF, NSA can maintain the integrity of target information in TAI while effectively suppressing non‐coherent background clutter. Conclusions NSA can effectively reduce non‐coherent background noise while ensuring the completeness of the target information. So, NSA offers the potential to provide high‐quality thermoacoustic images and further advance their clinical application.
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