97 research outputs found

    A Method of Decreasing Time Delay for A Tele-surgery System

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    Abstract -The haptics-based master-slave system for Minimally Invasive Surgery is a promising way to protect surgeons from long time radiation and to train novice doctors to learn basic wire or catheter handling skills. However, the time delay of transmission of visual video and the time difference between image information and force signals restrict the application of this technology in some extent. In this paper, we proposed a new method to reduce time delay effectively. At the slave side, the tip of the active catheter is tracked in real time to provide information on the location of the catheter in the blood vessel model. And then transmitted the coordinate values to the master site. At the master site, the location of the catheter was reappeared in the navigation chart which is the same structure with the blood vessels at master side according to the coordinate values received from the slave side. Therefore the transmission time of image information is decreased. Experimental results are given to illustrate the accuracy of our method

    Involvement of Glutamate Transporter-1 in Neuroprotection against Global Brain Ischemia-Reperfusion Injury Induced by Postconditioning in Rats

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    Ischemic postconditioning refers to several transient reperfusion and ischemia cycles after an ischemic event and before a long duration of reperfusion. The procedure produces neuroprotective effects. The mechanisms underlying these neuroprotective effects are poorly understood. In this study, we found that most neurons in the CA1 region died after 10 minutes of ischemia and is followed by 72 hours of reperfusion. However, brain ischemic postconditioning (six cycles of 10 s/10 s reperfusion/re-occlusion) significantly reduced neuronal death. Significant up-regulation of Glutamate transporter-1 was found after 3, 6, 24, 72 hours of reperfusion. The present study showed that ischemic postconditioning decreases cell death and that upregulation of GLT-1 expression may play an important role on this effect

    Efficacy and safety of triazavirin therapy for coronavirus disease 2019 : A pilot randomized controlled trial

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    Acknowledgements: We are deeply grateful to the front-line clinicians who participated in the study while directly fighting the epidemic. This study was supported by the Chinese Academy of Engineering Projects for COVID-19 (2020-KYGG-01-04) and Heilongjiang Province Urgent Project-6 for COVID-19. Data and safety monitoring board members of this trial included Kang Li, Yong Zhang, Songjiang Liu, and Yaohui Shi.Peer reviewedPublisher PD

    Network Pharmacology Based Research on the Combination Mechanism Between Escin and Low Dose Glucocorticoids in Anti-rheumatoid Arthritis

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    Rheumatoid arthritis (RA) is characterized by chronic progressive symmetrical synovitis and destruction of multiple joints. Glucocorticoids (GCs) are widely used in the treatment of RA. However, their adverse effects can be serious. Escin, which is isolated from Aesculus hippocastanum L., has been reported to have anti-inflammatory effects. We investigated the anti-RA effect of Escin combined with low dose GCs (dexamethasone, Dex) and the underlying mechanism. Adjuvant-induced RA rats and lipopolysaccharides (LPS)-injured RAW264.7 cells were used to investigate the anti-RA effects of Escin combined with low dose Dex in vivo and in vitro. The results showed that Escin combined with low-dose Dex significantly decreased arthritic index, serum IL-6 and TNF-α levels, reduced paw swelling, and ameliorated the joint pathology and immune organ pathology. Gene chip results revealed that Nr3c1 (GR) expression was significantly altered, and that GR was activated by Escin and low dose Dex in vivo and in vitro. Additionally, Escin combined with low dose Dex also significantly increased GR mRNA expression. However, when GR expression was suppressed by its specific inhibitor, the anti-RA effect of Escin combined with low-dose Dex was abolished. The data in this study demonstrated that Escin combined with Dex reduced the dose of Dex, and exerted significant anti-RA effects, which could also reduce the adverse effects of Dex. This combination might result from GR activation. This study might provide a new combination of drugs for the treatment of RA

    Transcriptional and Post-Transcriptional Mechanisms for Oncogenic Overexpression of Ether À Go-Go K+ Channel

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    The human ether-à-go-go-1 (h-eag1) K+ channel is expressed in a variety of cell lines derived from human malignant tumors and in clinical samples of several different cancers, but is otherwise absent in normal tissues. It was found to be necessary for cell cycle progression and tumorigenesis. Specific inhibition of h-eag1 expression leads to inhibition of tumor cell proliferation. We report here that h-eag1 expression is controlled by the p53−miR-34−E2F1 pathway through a negative feed-forward mechanism. We first established E2F1 as a transactivator of h-eag1 gene through characterizing its promoter region. We then revealed that miR-34, a known transcriptional target of p53, is an important negative regulator of h-eag1 through dual mechanisms by directly repressing h-eag1 at the post-transcriptional level and indirectly silencing h-eag1 at the transcriptional level via repressing E2F1. There is a strong inverse relationship between the expression levels of miR-34 and h-eag1 protein. H-eag1antisense antagonized the growth-stimulating effects and the upregulation of h-eag1 expression in SHSY5Y cells, induced by knockdown of miR-34, E2F1 overexpression, or inhibition of p53 activity. Therefore, p53 negatively regulates h-eag1 expression by a negative feed-forward mechanism through the p53−miR-34−E2F1 pathway. Inactivation of p53 activity, as is the case in many cancers, can thus cause oncogenic overexpression of h-eag1 by relieving the negative feed-forward regulation. These findings not only help us understand the molecular mechanisms for oncogenic overexpression of h-eag1 in tumorigenesis but also uncover the cell-cycle regulation through the p53−miR-34−E2F1−h-eag1 pathway. Moreover, these findings place h-eag1 in the p53−miR-34−E2F1−h-eag1 pathway with h-eag as a terminal effecter component and with miR-34 (and E2F1) as a linker between p53 and h-eag1. Our study therefore fills the gap between p53 pathway and its cellular function mediated by h-eag1

    Variance-Constrained Robust Estimation for Discrete-Time Systems with Communication Constraints

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    This paper is concerned with a new filtering problem in networked control systems (NCSs) subject to limited communication capacity, which includes measurement quantization, random transmission delay, and packets loss. The measurements are first quantized via a logarithmic quantizer and then transmitted through a digital communication network with random delay and packet loss. The three communication constraints phenomena which can be seen as a class of uncertainties are formulated by a stochastic parameter uncertainty system. The purpose of the paper is to design a linear filter such that, for all the communication constraints, the error state of the filtering process is mean square bounded and the steady-state variance of the estimation error for each state is not more than the individual prescribed upper bound. It is shown that the desired filtering can effectively be solved if there are positive definite solutions to a couple of algebraic Riccati-like inequalities or linear matrix inequalities. Finally, an illustrative numerical example is presented to demonstrate the effectiveness and flexibility of the proposed design approach

    Agricultural Environmental Information Collection Device Based on Raspberry Pi

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    International audienceIntegrated agricultural environmental information real-time collection, transmission and management is extremely critical for precision agriculture (PA). This paper describes the basic knowledge and primary principles used in an agricultural environmental information collection device. The device is based on Raspberry Pi, combining with GPS module, some digital sensors and analog sensors to measure environmental temperature and humidity, barometric pressure, light intensity, soil moisture and other environmental information accurate collection. All collected data was real-time transmitted to a remote server specified database for management. In the experiment process, the device has been proved to have the ability to catch the distributed information and also can get different centralized data management. The results show the integration of operational information collection, transmission and management, as well as the use of open source software to make it easy to collect multiple types of data parallelism, which provides an important solution for the rapid transformation of agricultural production

    Analysis of the Correlation between Middle-season Rice Yield and Meteorological Factors in Jingdong County from 2009 to 2016

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    Middle-season rice is an important food crop in southern rice areas of China, especially in Yunnan, the main rice-producing region. However, due to the impact of low temperature at the seedling stage and high or low temperature at the booting and heading stage of middle-season rice, the yield is not stable.Based on the data of yield factors of different middle-season rice varieties planted in the same ecological site in Jingdong County from 2009 to 2016, average development period was calculated using the data of development period measured in field during 2009-2016, and the average of meteorological factors (daily average temperature, daily maximum temperature, daily minimum temperature, and sunshine hours) and total precipitation were calculated. The correlation between meteorological factors in different development periods of each year and corresponding per unit area yield was analyzed. Temperature is the most important factor affecting rice yield. Sufficient light is beneficial to the increase in the number of grains per spike and thousand seed weight in the sowing-seedling emergence stage and milk maturity-maturity stage. Excessive precipitation will reduce the number of grains per spike in the booting-heading stage. Excessive precipitation decreases the number of filled grains per spike in the jointing-booting stage, and proper drainage helps increase the formation rate of ears. In this study, the main meteorological factors affecting rice yield were analyzed to provide scientific reference for rice production and management in this county in future
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