11 research outputs found

    Electrochemical Study of DPPH Radical Scavenging for Evaluating the Antioxidant Capacity of Carbon Nanodots

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    Carbon nanodots (CNDs) have become one of the potential candidates for antioxidants due to their excellent luminescence, biocompatibility, and lower cytotoxicity. While CNDs have experienced some research on radical scavenging activity via UV–vis spectroscopy, the relationship between reserved 2,2-diphenyl-1-picrylhydrazyl radical (DPPH<sup>•</sup>) concentration and CNDs’ incubation concentration remains unclear. This work describes an electrochemical study on the changes of redox peaks of the oxidation of DPPH<sup>•</sup> at gold electrodes with addition of different concentrations of a type of microwave-synthesized CND (U-dots). The result is consistent with a UV–vis absorption dose-dependent study used to quantify the antioxidation activities. Combined with standard heterogeneous electron-transfer rate constant analysis, electrochemical study gives a coupled hydrogen atom transfer (HAT) mechanism for DPPH<sup>•</sup> scavenging by the U-dots. This work provides a new perspective on the antioxidative study of the U-dots, which may aid their development for practical use in biomedicine

    Magnetoreception of Photoactivated Cryptochrome 1 in Electrochemistry and Electron Transfer

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    Cryptochromes are flavoproteins whose photochemistry is important for crucial functions associated with phototropism and circadian clocks. In this report, we, for the first time, observed a magnetic response of the cryptochrome 1 (CRY1) immobilized at a gold electrode with illumination of blue light. These results present the magnetic field-enhanced photoinduced electron transfer of CRY1 to the electrode by voltammetry, exhibiting magnetic responsive rate constant and electrical current changes. A mechanism of the electron transfer, which involves photoinduced radicals in the CRY, is sensitive to the weak magnetic field; and the long-lived free radical FAD<sup>•–</sup> is responsible for the detected electrochemical Faradaic current. As a photoreceptor, the finding of a 5.7% rate constant change in electron transfer corresponding to a 50 μT magnetic field may be meaningful in regulation of magnetic field signaling and circadian clock function under an electromagnetic field

    Alternative SiO<sub>2</sub> Surface Direct MDCK Epithelial Behavior

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    The mechanical interactions of cells are mediated through adhesive interactions. In this study, we examined the growth, cellular behavior, and adhesion of MDCK epithelial cells on three different SiO<sub>2</sub> substrates: amorphous glass coverslips and the silicon oxide layers that grow on ⟨111⟩ and ⟨100⟩ wafers. While compositionally all three substrates are almost similar, differences in surface energy result in dramatic differences in epithelial cell morphology, cell–cell adhesion, cell–substrate adhesion, actin organization, and extracellular matrix (ECM) protein expression. We also observe striking differences in ECM protein binding to the various substrates due to the hydrogen bond interactions. Our results demonstrate that MDCK cells have a robust response to differences in substrates that is not obviated by nanotopography or surface composition and that a cell’s response may manifest through subtle differences in surface energies of the materials. This work strongly suggests that other properties of a material other than composition and topology should be considered when interpreting and controlling interactions of cells with a substrate, whether it is synthetic or natural

    Development an arm robot to simulate the lead-pipe rigidity for medical education

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    Neurologic examination takes an important role in the physical examination. It requires abundant knowledge with prominent skills. Normally, the medical staffs, especially novices are trained to master the skills and accumulate experiences with several methods such as watching video, training with the simulated patient (SP), and so on. However, the drawbacks of the above methods, such as lack of multi-symptoms, lack of active interactions, etc, limit the training effects. To make up them, several kinds of medical training simulators have been developed to improve training effectiveness. However, most of these simulators just focus on mimicking the symptoms. The could not simulate the pathology of diseases. In this paper, we will propose an elbow robot named WKE-2(Waseda Kyotokagaku Elbow Robot No.2) to simulate the symptoms of motor nerve system for neurologic examination training on elbow force examination. In this paper, the mechanism of the elbow robot and physiological neurological model is described. As a sample, the performance of lead-pipe symptoms is introduced. Taking advantage of the robot, the trainee can get a full training on the examination skills and knowledge as well as the understanding of disease effection. Finally, several experiments are performed to verify the proposed robot. The results lead to the consideration that the approach is worth following in further research.

    Development of a rehabilitation robot for hand and wrist rehabilitation training

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    Up to now, the number of hemiplegia rehabilitation devices is increasing quickly along with hemiplegic patients'. But most of hand rehabilitation training just limit to the fingers flexible training of patients' affected hand. They not only ignore the importance of functional training of hand, but also wrist cooperative training during rehabilitation process. In our new research, we proposed a novel hand and wrist rehabilitation robot to achieve grasp functional training of hand except thumb and intorsion/extorsion and dorsiflexion/plantar flexion of wrist, which provides a creative hand rehabilitation way for hemiplegic patients. In this paper, we will introduce the detail design of the robot. It mainly includes two rehabilitation units - wrist rehabilitation unit and hand rehabilitation unit, which can realize separate motion or cooperate motion of hand and wrist based on patients' willingness. What's more, the torque sensor unit is purposely designed to detect feedback torque of related motion instead of available ones in the market, which makes the whole mechanical structure more compact. In a word, this novel hand and wrist rehabilitation robot will have a promising prospect

    Antioxidant Capacity of Nitrogen and Sulfur Codoped Carbon Nanodots

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    Carbon nanodots (CNDs) have shown potential for antioxidative activity at the cellular level. Here we applied a facile hydrothermal method to prepare fluorescent nitrogen and sulfur (N,S-)­codoped CNDs using α-lipoic acid, citric acid, and urea as precursor molecules. This work describes a comprehensive study for exploring their antioxidation activity using UV–vis absorption and electrochemistry measurements of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH<sup>•</sup>), as well as a lucigenin chemiluminescence (lucigenin-CL) assay. The lucigenin-CL assay detects superoxide anion radicals, i.e., reactive oxygen species (ROS) produced through the xanthine/xanthine oxidase (XO) reaction. The electrochemically derived relationship between the unreacted nitrogen-centered DPPH<sup>•</sup> and CND concentrations agrees with that obtained from UV–vis measurements. A reaction pathway for the ROS antioxidative reaction of N,S-codoped CNDs is proposed. These findings should aid in the development of N,S-codoped CNDs for practical use in biomedical applications

    Gait motion analysis based on WB-4 sensor with quaternion algorithm

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    Up to now, with the increasing of the elderly population, more and more patients are suffering from hemiplegia. The needs for hemiplegic rehabilitation is increasing quickly. As traditional rehabilitation, each patient must be treated by therapist, one by one. However, because of the different levels of therapists, the rehabilitation cannot be performed as the as the same. Normally, the rehabilitation status diagnosing is still be performed by therapists with the subjective experience. It caused the inhomogeneity on rehabilitation evaluation. It also sometimes causes negative influence on the rehabilitation effect. To solve these problems, many researches focusing on assessing the status of the hemiplegic patients quantitatively are proposed rehabilitation evaluation systems. Rehabilitation motion detection is the basis of the evaluation system, and it requires the participation of therapist. In this paper, a method is presented to detect lower limb motion of hemiplegic patients based on inertial sensor technology. The gesture quaternion of lower limb can be obtained through LPMS. With the matrix and Euler angle changing algorithm, combining with the simplified lower limb motion model, the rotation angle of joint can be computed. Finally, the curve of rotation angle of knee is established

    Data_Sheet_1_Molecular detection of Rickettsiales and a potential novel Ehrlichia species closely related to Ehrlichia chaffeensis in ticks (Acari: Ixodidae) from Shaanxi Province, China, in 2022 to 2023.docx

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    Important tick-borne diseases include spotted fever group Rickettsia (SFGR), Anaplasma, and Ehrlichia, which cause harm to animal and human health. Ixodidae are the primary vectors of these pathogens. We aimed to analyze the prevalence and genetic diversity of SFGR, Anaplasma, and Ehrlichia species in the Ixodidae in Shaanxi Province, China. Herein, 1,113 adult Ixodidae ticks were collected from domestic cattle and goats, and detected using nested PCR. A total of four Ixodidae species were collected and Ca. R. jingxinensis (20.58%, 229/1113), A. bovis (3.05%, 34/1113), A. capra (3.32%, 37/1113), A. marginale (0.18%, 2/1113), E. sp. Yonaguni138 (0.18%, 2/1113), and a potent novel Ehrlichia species named E. sp. Baoji96 (0.09%, 1/1113) were detected. A. marginale was detected for the first time in Rhipicephalus microplus. E. sp. Baoji96 was closely related to E. chaffeensis and was first identified in Haemaphysalis longicornis. In addition, co-infection with two Rickettsiales pathogens within an individual tick was detected in 10 (1.54%) ticks. This study provides a reference for the formulation of biological control strategies for ticks and tick-borne diseases in Shaanxi Province, and could lead to an improved control effect.</p
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