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Background: Hemorrhagic shock was a leading cause of death worldwide, with myocardial injury being a primary affected organ. As commonly used solutions in fluid resuscitation, acetated Ringer's (AR) and Lactate Ringer's solution (LR) were far from perfect for their adverse reactions such as lactic acidosis and electrolyte imbalances. In previous studies, TPP@PAMAM-MR (TPP-MR), a novel nanocrystal resuscitation fluid has been found to protect against myocardial injury in septic rats. However, its role in myocardial injury in rats with hemorrhagic shock and underlying mechanism is unclear. Methods: The hemorrhagic shock rats and hypoxia-treated cardiomyocytes (H9C2) were utilized to investigate the impact of TPP-MR on cardiac function, mitochondrial function, and lipid peroxidation. The expressions of ferritin-related proteins glutathione peroxidase 4 (GPX4), Acyl CoA Synthase Long Chain Family Member 4 (ACSL4), and Cyclooxygenase-2(COX2) were analyzed through Western blotting to explore the mechanism of TPP-MR on hemorrhagic myocardial injury. Results: TPP-MR, a novel nanocrystalline resuscitation fluid, was synthesized using TPP@PAMAM@MA as a substitute for L-malic acid. We found that TPP-MR resuscitation significantly reduced myocardial injury reflected by enhancing cardiac output, elevating mean arterial pressure (MAP), and improving perfusion. Moreover, TPP-MR substantially prolonged hemorrhagic shock rats' survival time and survival rate. Further investigations indicated that TPP-MR improved the mitochondrial function of myocardial cells, mitigated the production of oxidative stress agents (ROS) and increased the glutathione (GSH) content. Additionally, TPP-MR inhibited the expression of the ferroptosis-associated GPX4 protein, ACSL4 and COX2, thereby enhancing the antioxidant capacity. Conclusion: The results showed that TPP-MR had a protective effect on myocardial injury in rats with hemorrhagic shock, and its mechanism might be related to improving the mitochondrial function of myocardial cells and inhibiting the process of ferroptosis.
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Ferroptose , Miócitos Cardíacos , Nanopartículas , Choque Hemorrágico , Animais , Choque Hemorrágico/tratamento farmacológico , Choque Hemorrágico/terapia , Ratos , Ferroptose/efeitos dos fármacos , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Nanopartículas/química , Ressuscitação/métodos , Ratos Sprague-Dawley , Linhagem Celular , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Ciclo-Oxigenase 2/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacosRESUMO
The thermal properties of bipolar plates, being key elements of polymer electrolyte membrane fuel cells, significantly affect their heat conduction and management. This study employed an innovative approach known as a heat flow loop integral method to experimentally assess the in-plane thermal conductivity of graphite bipolar plates, addressing the constraints of traditional methods that have strict demands for thermal stimulation, boundary or initial conditions, and sample size. This method employs infrared thermal imaging to gather information from the surface temperature field of the sample, which is induced by laser stimulation. An enclosed test loop on the infrared image of the sample's surface, situated between the heat source and the sample's boundary, is utilized to calculate the in-plane heat flow density by integrating the temperature at the sampling locations on the loop and the in-plane thermal conductivity can be determined based on Fourier's law of heat conduction. The numerical simulation analysis of the graphite models and the experimental tests with aluminum have confirmed the precision and practicality of this method. The results of 1060 aluminum and 6061 aluminum samples, each 1 and 2 mm in thickness, show a deviation between the reference and actual measurements of the in-plane thermal conductivity within 4.3% and repeatability within 2.7%. Using the loop integral method, the in-plane thermal conductivities of three graphite bipolar plates with thicknesses of 0.5 mm, 1 mm, and 1.5 mm were tested, resulting in 311.98 W(m·K)-1, 314.41 W(m·K)-1, and 323.48 W(m·K)-1, with repeatabilities of 0.9%, 3.0%, and 2.0%, respectively. A comparison with the reference value from the simulation model for graphite bipolar plates with the same thickness showed a deviation of 4.7%. The test results for three different thicknesses of graphite bipolar plates show a repeatability of 2.6%, indicating the high consistency and reliability of this measurement method. Consequently, as a supplement to existing technology, this method can achieve a rapid and nondestructive measurement of materials such as graphite bipolar plates' in-plane thermal conductivity.
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The essential factors of information-aware systems are heterogeneous multi-sensory devices. Because of the ambiguity and contradicting nature of multi-sensor data, a data-fusion method based on the cloud model and improved evidence theory is proposed. To complete the conversion from quantitative to qualitative data, the cloud model is employed to construct the basic probability assignment (BPA) function of the evidence corresponding to each data source. To address the issue that traditional evidence theory produces results that do not correspond to the facts when fusing conflicting evidence, the three measures of the Jousselme distance, cosine similarity, and the Jaccard coefficient are combined to measure the similarity of the evidence. The Hellinger distance of the interval is used to calculate the credibility of the evidence. The similarity and credibility are combined to improve the evidence, and the fusion is performed according to Dempster's rule to finally obtain the results. The numerical example results show that the proposed improved evidence theory method has better convergence and focus, and the confidence in the correct proposition is up to 100%. Applying the proposed multi-sensor data-fusion method to early indoor fire detection, the method improves the accuracy by 0.9-6.4% and reduces the false alarm rate by 0.7-10.2% compared with traditional and other improved evidence theories, proving its validity and feasibility, which provides a certain reference value for multi-sensor information fusion.
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In a low-temperature environment, the actuation performance of the piezoelectric stack results from the synergic action of the thermo-electro-mechanical field; the actuation performance is influenced by the change in temperature, compressive preload, and excitation voltage. A special and novel instrumentation system is proposed and developed in this study to measure the relationship between the actuation performance of the piezoelectric stack and the change in temperature, preload, and voltage. The bending strain of the cantilever beam driven by the piezoelectric stack reflects its actuation performance, and the corresponding theoretical model is established to optimize the experimental conditions and maximize the strain and signal-to-noise ratio. Based on the experimental results, it can be seen that the actuation performance of the piezoelectric stack increases linearly with the excitation voltage under different temperatures and preload conditions. The static actuation performance increased by 79%-90% when the prestress increased from 0 to 6 MPa, corresponding to a decrease of 15%-30% when the temperature decreased from 20 to -70 °C, and the dynamic actuation performance decreased with an increase in the frequency of the excitation voltage. Consequently, the design methods and ideas are informative to develop an instrumentation system that can measure the influence of thermo-electro-mechanical synergistic effects on the actuation performance of piezoelectric stacks under different temperatures, preloads, and voltages.
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BACKGROUND: Compared with the lung isolation using double-lumen endobronchial tube intubation, the artificial capnothorax using single-lumen endotracheal tube intubation has shown to be a safe, more convenient, and cost-effective procedure for thoracoscopic esophagectomy. However, the impact of capnothorax on coagulation is not well defined. Herein, we evaluate the impact of a capnothorax on coagulation and fibrinolysis in patients who undergoing thoracoscopic esophagectomy. METHODS: Between March 2014 and August 2014, 24 patients underwent thoracoscopic esophagectomies for esophageal cancer with the procedure of artificial capnothorax (group P); we also performed 24 thoracoscopic esophagectomy cases without using capnothorax (group N). The demographics and arterial blood gas, as well as the parameters of coagulation and fibrinolysis, of the two groups were analyzed. RESULTS: The pH value of group P after CO2 insufflation was significantly lower than in group N (P < 0.05), and the partial pressure of carbon dioxide (PaCO2) was significantly increased compared with group N (P < 0.05). The R and K values after CO2 insufflation were significantly longer than before anesthesia (P < 0.05), and both α angle and MA value after CO2 insufflation were significantly lower than those before anesthesia (P < 0.05). No significant differences in R value, K value, α angle, or MA value were observed between pre-anesthesia and termination of capnothorax. No significant difference in LY30 data was found between different groups (P > 0.05). CONCLUSION: Artificial capnothorax in patients receiving endoscopic resection of esophageal carcinoma had a significant impact on coagulation. These patients showed significant impairments in coagulation not observed in patients without artificial capnothorax.
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Transtornos da Coagulação Sanguínea/epidemiologia , Dióxido de Carbono/efeitos adversos , Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Hipercapnia/epidemiologia , Insuflação/efeitos adversos , Complicações Intraoperatórias/epidemiologia , Pneumotórax Artificial/efeitos adversos , Toracoscopia/métodos , Idoso , Coagulação Sanguínea , Transtornos da Coagulação Sanguínea/etiologia , Gasometria , Carcinoma de Células Escamosas do Esôfago , Feminino , Humanos , Concentração de Íons de Hidrogênio , Hipercapnia/etiologia , Complicações Intraoperatórias/etiologia , Masculino , Pessoa de Meia-Idade , Pneumotórax Artificial/métodos , TromboelastografiaRESUMO
We aim to assess efficacy and safety of remifentanil or sulfentanyl combined with propofol during painless gastroscopic examination in patients. In this study, 270 patients were randomly divided into 3 groups: propofol was given only in group P; propofol and remifentanil in group PR; propofol and sulfentanyl in group PS during the gastroscopic examination. Efficiency of group P was significantly higher than that of group PR and PS (P<0.01) [corrected]. Efficiency of group PR was lower than that of group PS (P<0.05). Incidence of chest wall rigidity and oxygen desaturation in group PR were higher than group P and PS (P<0.05), whereas there was no difference between groups P and PS (P>0.05). Propofol combined with remifentanil could provide satisfying anesthesia and more respiratory depression, whereas sulfentanyl at equivalent dose combined with propofol could also provide with satisfying anesthesia and less respiratory depression. Combined sufentanyl with propofol would be an effective anesthesia technique in the daytime procedure.
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Anestesia Intravenosa/métodos , Gastroscopia/métodos , Medição da Dor/métodos , Piperidinas/administração & dosagem , Sufentanil/administração & dosagem , Adolescente , Adulto , Anestésicos Intravenosos/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/efeitos dos fármacos , Estudos Prospectivos , Remifentanil , Adulto JovemRESUMO
Based on the studies of electrochemiluminescence(ECL) of luminol in neutral medium, the iodide would greatly sensitize the ECL of luminol. The ECL luminous intensity responded linearly to the concentration of iodide within the range of 3.8 x 10(-7) mol x L(-1) to 2.2 x 10(-6) mol x L(-1), and the detection limit is 4.0 x 10(-8) mol x L(-1). The mechanism of enhancement effect of iodide on luminol's ECL is also discussed. The experimental results showed that it was a free radical procedure.