82 research outputs found

    An electro-pneumatic force tracking system using fuzzy logic based volume flow control

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    In this paper, a fuzzy logic based volume flow control method is proposed to precisely control the force of a pneumatic actuator in an electro-pneumatic system including four on-off valves. The volume flow feature, which is the relationship between the duty cycle of the pulse width modulation (PWM) period, pressure difference, and volume flow of an on-off valve, is based on the experimental data measured by a high-precision volume flow meter. Through experimental data analysis, the maximum and minimum duty cycles are acquired. A new volume flow control method is introduced for the pneumatic system. In this method, the raw measured data are innovatively processed by a segmented, polynomial fitting method, and a newly designed procedure for calculating the duty cycle is adopted. This procedure makes it possible to combine the original data with fuzzy logic control (FLC). Additionally, the method allows us to accurately control the minimum and maximum opening pulse width of the valve. Several experiments are performed based on the experimental data, instead of the traditional theoretical models. Only 0.141 N (1.41%) overshoot and 0.03 N (0.03%) steady-state error are observed in the step response experiment, and 0.123 N average error is found while tracking the sine wave reference

    Characterization of the complete mitochondrial genome and phylogenetic analysis of Pelodiscus sinensis, a mutant Chinese soft-shell turtle

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    The Chinese soft-shell turtle (Pelodiscus sinensis, Testudines: Pelodiscus) shows geographical variation, and one strain is the inked turtle. Wild population numbers have dropped substantially during the past decades, and the species is now classed as vulnerable. However, little genetic data exists so this study aimed to sequence and analyze the complete mitochondrial genome. The circular double-stranded genome is 17,145 bp in length and contains 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes, an L-strand replication origin and a control region. The base composition is 35.5% A, 27.3% T, 11.8% G and 25.4% C, with an AT content of 62.8%. Trionychidae species were divided into two clades based on phylogenetic analysis, and the closest genetic distance was between Trionyx axenaria and P. sinensis. This study provides basic genetic data for future studies on conservation biology, phylogenetic and evolutionary analysis of this inked strain of the Chinese soft-shell turtle.</p

    Coding the negative emotions of family members and patients among the high-risk preoperative conversations with the Chinese version of VR-CoDES

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    Abstract Background Little is known about family members' and patients' expression of negative emotions among high‐risk preoperative conversations. Objectives This study aimed to identify the occurrence and patterns of the negative emotions of family members and patients in preoperative conversations, to investigate the conversation themes and to explore the correlation between the negative emotions and the conversation themes. Methods A retrospective study was conducted using the Chinese version of Verona Coding Definitions of Emotional Sequences (VR‐CoDES‐C) to code 297 conversations on high‐risk procedures. Inductive content analysis was used to analyse the topics in which negative emotions nested. The χ2 Test was used to test the association between the cues and the conversation themes. Results The occurrence rate of family members' and patients' negative emotions was very high (85.9%), much higher when compared to most conversations under other medical settings. The negative emotions were mainly expressed by cues (96.4%), and cue‐b (67.4%) was the most frequent category. Cues and concerns were mostly elicited by family members and patients (71.6%). Negative emotions were observed among seven themes, in which ‘Psychological stress relating to illness severity, family's care and financial burden’ (30.3%) ranked the top. Cue‐b, cue‐c and cue‐d had a significant correlation (p < .001) with certain themes. Conclusions Family members and patients conveyed significantly more negative emotions in the high‐risk preoperative conversations than in other medical communications. Certain categories of cues were induced by specific emotional conversation contents. Patient Contribution Family members and patients contributed to data

    Fibroblast growth factor (FGF21) protects mouse liver against D-galactose-induced oxidative stress and apoptosis via activating Nrf2 and PI3K/Akt pathways

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    FGF21 is recently discovered with pleiotropic effects on glucose and lipid metabolism. However, the potential protective effect of FGF21 against D-gal-induced injury in the liver has not been demonstrated. The aim of this study is to investigate the pathophysiological role of FGF21 on hepatic oxidative injury and apoptosis in mice induced by D-gal. The 3-month-old Kunming mice were subcutaneously injected with D-gal (180 mg kg(-1) d(1)) for 8 weeks and administered simultaneously with FGF21 (5 or 1 mg kg(-1) d(1)). Our results showed that the administration of FGF21 significantly alleviated histological lesion including structure damage, degeneration, and necrosis of hepatocytes induced by D-gal, and attenuated the elevation of liver injury markers, serum AST, and ALP in a dosedependent manner. FGF21 treatment also suppressed D-galinduced profound elevation of ROS production and oxidative stress, as evidenced by an increase of the MDA level and depletion of the intracellular GSH level in the liver, and restored the activities of antioxidant enzymes SOD, CAT, GSH-Px, and T-AOC. Moreover, FGF21 treatment increased the nuclear abundance of Nrf2 and subsequent up regulation of several antioxidant genes. Furthermore, a TUNEL assay showed that D-gal-induced apoptosis in the mouse liver was significantly inhibited by FGF21. The expression of caspase-3 was markedly inhibited by the treatment of FGF21 in the liver of D-gal-treated mice. The levels of PI3K and PBK/Akt were also largely enhanced, which in turn inactivated pro-apoptotic signaling events, restoring the balance between pro-and anti-apoptotic Bcl-2 and Bax proteins in the liver of D-gal-treated mice. In conclusion, these results suggest that FGF21 protects the mouse liver against D-gal-induced hepatocyte oxidative stress via enhancing Nrf2-mediated antioxidant capacity and apoptosis via activating PI3K/Akt pathway
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