49 research outputs found
Research on parallel nonlinear control system of PD and RBF neural network based on U model
The modelling problem of nonlinear control system is studied, and a higher generality nonlinear U model is established. Based on the nonlinear U model, RBF neural network and PD parallel control algorithm are proposed. The difference between the control input value and the output value of the neural network is taken as the learning target by using the online learning ability of the neural network. The gradient descent method is used to adjust the PD output value, and ultimately track the ideal output. The Newton iterative algorithm is used to complete the transformation of the nonlinear model, and the nonlinear characteristic of the plant is reduced without loss of modelling precision, consequently, the control performance of the system is improved. The simulation results show that RBF neural network and PD parallel control system can control the nonlinear system. Moreover, the control system with Newton iteration can improve the control effect and anti-interference performance of the system
An Evaluation Study on the Level of China's Low-Carbon Manufacturing Based on Factor Analysis
AbstractBased on the absorption of some relevant research results, this paper establishes an evaluation model of the level of China's low-carbon manufacturing and uses the factor analysis method for empirical research. Then it analyses the exist problems of China's low-carbon manufacturing and puts forward some relevant countermeasures and suggestions
Electroacupuncture at PC6 (Neiguan) Improves Extracellular Signal-Regulated Kinase Signaling Pathways Through the Regulation of Neuroendocrine Cytokines in Myocardial Hypertrophic Rats
Electroacupuncture (EA) therapy has been widely accepted as a useful therapeutic technique with low or no risk in the clinical prevention of cardiac hypertrophy. However, the signaling transduction mechanism underlying this effect remains unclear. The current study investigates the effects of EA on the signaling pathways of myocardial hypertrophy (MH) in rats. Up to 40 3-month-old Sprague-Dawley (SD) rats were randomly divided into normal, model, PC6 (Neiguan), and LI4 (Hegu) groups, with ten rats in each group. All the rats except for the normal group received 3 mg/kg·d of isoprinosine hydrochloride (ISO) injection into the back skin. The rats in the PC6 and LI4 groups received EA for 14 days. On the 15th day, electrocardiograms were recorded, and the ultrastructure of the myocardial cells was observed. The myocardial hypertrophy indices (MHIs), electrocardiograph (ECG), ultrastructure observation, levels of plasma angiotensin II (Ang II) and endothelin (ET), as well as protein expression of extracellular signal-regulated kinase (ERK), and phosphorylation extracellular signal regulating kinase (p-ERK) in the left ventricular myocardial tissue were measured. The results indicated that EA can improve cardiac function in MH rats by modulating upstream neuroendocrine cytokines that regulate the ERK signaling pathways
Anti-inflammatory and antioxidant activity of ursolic acid: a systematic review and meta-analysis
Introduction: There is currently evidence suggesting that ursolic acid may exert a favorable influence on both anti-inflammatory and antioxidant impact. Nevertheless, the anti-inflammatory and antioxidant activities of ursolic acid have not been systematically evaluated. Consequently, this study aims to conduct a systematic review and meta-analysis regarding the impact of ursolic acid on markers of inflammatory and antioxidant activity in both animal models and in vitro systems.Methods: The search encompassed databases such as PubMed, Web of Science, Google Scholar, and ScienceDirect, up until May 2023. All eligible articles in English were included in the analysis. Standard mean difference (SMD) was pooled using a random-effects model, and the included studies underwent a thorough assessment for potential bias.Results: The final review comprised 31 articles. In disease-model related studies, animal experiments have consistently shown that ursolic acid significantly reduced the levels of inflammatory parameters IL-1β, IL-6 and TNF-α in mouse tissues. In vitro studies have similarly showed that ursolic acid significantly reduced the levels of inflammatory parameters IL-1β, IL-6, IL-8 and TNF-α. Our results showed that ursolic acid could significantly elevate SOD and GSH levels, while significantly reducing MDA levels in animal tissues. The results of in vitro studies shown that ursolic acid significantly increased the level of GSH and decreased the level of MDA.Discussion: Findings from both animal and in vitro studies suggest that ursolic acid decreases inflammatory cytokine levels, elevates antioxidant enzyme levels, and reduces oxidative stress levels (graphical abstract). This meta-analysis furnishes compelling evidence for the anti-inflammatory and antioxidant properties of ursolic acid
Tubeless video-assisted thoracic surgery for pulmonary ground-glass nodules: expert consensus and protocol (Guangzhou)
Comparative Analysis of Roots from <i>Vicatia thibetica</i> de Boiss and <i>Angelica sinensis</i> Based on Chemical Composition, Antioxidant, Nitrite-Scavenging and Enzyme Inhibition Activities
Radix Vicatia thibetica de Boiss (RVT) is locally known as “Xigui” or “Dujiao-danggui” in Tibetan medicine and is often used as a substitute for Radix Angelica sinensis (RAS) in daily nourishing diets and clinical applications. In this study, we determined and compared the contents of polysaccharides, total coumarins, ferulic acid, total phenols, total flavonoids, chlorogenic acid, protein, and amino acids, and the composition of volatile oil in RVT and RAS. Biological activities, including antioxidants, scavenging of nitrite, inhibition of tyrosinase, thrombin, and coagulation FXa, were comparatively evaluated. Results showed that RVT contains more polysaccharides, phenols, flavonoids, proteins, glutamic acid, and lysine as compared to RAS. Among volatile compounds, 14 species are similar, and 20 species are different in RVT and RAS. Overall, among volatile compounds, the content of 3-N-Butylphthalide was higher, whereas the content of ligustilide was lower in RVT volatile oil. A significant difference was reported in the bioactivity of RVT and RAS. The biological activity of RVT had higher antioxidant, nitrite scavenging, and tyrosinase inhibitory activities, whereas it showed much lower thrombin and FXa inhibitory activities. Correlation analysis showed that the antioxidant, nitrite scavenging, and tyrosinase inhibitory activities were related to the phenol and flavonoid content, whereas the thrombin and FXa inhibitory activities were related to ferulic acid and volatile oil content. This study presents a comparative analysis of RAS and RVT’s chemical compositions of antioxidant, nitrite-scavenging, inhibition of tyrosinase, thrombin, and coagulation FXa activities. It was found that both RVT and RAS have their unique advantages, and RVT has the potential to be utilized as functional foods, cosmetics, and medical products
Effects of Carbon Emission Trading on Companies’ Market Value: Evidence from Listed Companies in China
Emissions trading schemes (ETSs) are effective measures that facilitate economic growth and carbon mitigation, especially for developing countries such as China. These schemes can further affect the cash flow, production, and investment decisions of regulated companies. However, few empirical studies have explored how ETSs promote companies’ market value. We systematically evaluate the influence of the carbon emission trading (CET) policy on companies’ market value and explore the influential mechanism. We use the data of listed companies from the Chinese stock “A” markets and employ the difference-in-difference method to account for the unobserved cause of the CET policy regarding companies’ market value. Robust benchmark regression results reveal that the CET policy promotes companies’ market value significantly. The mechanism analysis reveals that the CET policy can improve the market value of listed companies by influencing the carbon price, innovative activities, and carbon disclosure. The results of the heterogeneity analysis show that the CET policy’s impact on companies’ market value is heterogeneous in terms of marketization degree, industry, firm ownership, and different regions. We suggest that the carbon pricing mechanism, degree of market perfection, carbon disclosure policy, and carbon finance should be optimized to improve the efficiency of ETSs
Detection of Cu2+ in Water Based on Histidine-Gold Labeled Multiwalled Carbon Nanotube Electrochemical Sensor
Based on the strong interaction between histidine and copper ions and the signal enhancement effect of gold-labeling carbon nanotubes, an electrochemical sensor is established and used to measure copper ions in river water. In this study the results show that the concentrations of copper ion have well linear relationship with the peak current in the range of 10−11–10−7 mol/L, and the limit of detection is 10−12 mol/L. When using this method to detect copper ions in the Xiangjiang River, the test results are consistent with the atomic absorption method. This study shows that the sensor is convenient to be used in daily monitoring of copper ions in river water
Effect of Variety and Maturity Index on the Physicochemical Parameters Related to Virgin Olive Oil from Wudu (China)
Physical parameters (i.e., extraction yield, oil content), chemicals (i.e., fatty acids, phenolics) and oxidative stability associated with virgin olive oil (VOO) from ten varieties in Wudu, China, were analyzed as a function of maturity index and variety by multivariate analysis models. Most of the analytical parameters were significantly affected by the variety and maturity index, and the former was more influential than the latter. Phenolics were the principal factor dividing the ten varieties into four groups. High phenolic levels were observed in the ‘Koroneiki’ group and ‘Manzanilla’ group, but the oil extractability index differentiated between them, being the highest and lowest, respectively. The ‘Koroneiki’ group demonstrated high oil productivity and oil quality, which was worthy of promotion in large-scale cultivation. High amounts of linoleic enhanced the VOO health benefits of ‘Ascolana tenera, Arbequina and Zhongshan24’ group, but brought the risk of shortening the shelf-life. The ‘Ulliri Bardhe, Empeltre, Ezhi8, Yuntai14 and Picual’ group clustered for the higher relative value of oleic acid. The maturity index had significant negative effects on the content of total phenolics, oleacein, oleocanthal, and oleic acid, but had a positive effect on the extractability index, which suggested that varieties with low phenolics and oleic acid levels should be harvested early
Comparison of intrathecal low-dose bupivacaine and morphine with intravenous patient control analgesia for postoperative analgesia for video-assisted thoracoscopic surgery
Abstract Background Thoracoscopic surgical techniques continue to advance, yet the intensity of postoperative pain remains significant, impeding swift patient recovery. This study aimed to evaluate the differences in postoperative pain and recuperation between patients receiving intrathecal morphine paired with low-dose bupivacaine and those administered general anesthesia exclusively. Methods This randomized controlled trial enrolled 100 patients, who were allocated into three groups: Group M (5 μg/kg morphine intrathecal injection), Group B (5 μg/kg morphine combined with bupivacaine 3 mg intrathecal injection) and Group C (intrathecal sham injection). The primary outcome was the assessment of pain relief using the Numeric Rating Scale (NRS). Additionally, intraoperative remifentanil consumption was quantified at the end of the surgery, and postoperative opioid use was determined by the number of patient-controlled analgesia (PCIA) compressions at 48 h post-surgery. Both the efficacy of the treatments and any complications were meticulously recorded. Results Postoperative NRS scores for both rest and exercise at 6, 12, 24, and 48 h were significantly lower in groups M and B than in group C (P0.05). There was no significant difference in intraoperative propofol dosage across all three groups (P>0.05). Postoperative dosages of both sufentanil and Nonsteroidal anti‐inflammatory drugs (NSAIDs) were significantly less in groups M and B compared to group C (P<0.05). The time of first analgesic request was later in both groups M and B than in group C (P<0.05). Specific and total scores were elevated at 2 days postoperative when compared to scores at 1 day for all groups (P<0.05). Furthermore, at 1 day and 2 days postoperatively, both specific scores and total scores were higher in groups M and B compared to group C (P<0.05). Conclusion Intrathecal administration of morphine combined with bupivacaine has been shown to effectively ameliorate acute pain in patients undergoing thoracoscopic surgery. Trial registration The trial was registered on ClinicalTrials.gov: ChiCTR2200058544, registered 10/04/2022