67 research outputs found

    An efficient route for electrooxidation of methanol to dimethoxymethane using ionic liquid as electrolyte

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    An ionic liquid 1-ethyl-3-methyl imidazolium tetrafloroborate (EmimBF4) was found to be highly active for one-pot synthesis of dimethoxymethane (DMM) by electrooxidation of methanol on platinum electrode, exhibiting 34.7% conversion, 96.9% selectivity to DMM, high current efficiency (99.2%) as well. The electrode reaction mechanism was proposed according to the experimental results and reported literature

    Quantitative Determination of Fibrinogen of Patients with Coronary Heart Diseases through Piezoelectric Agglutination Sensor

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    Fibrinogen can transform fibrin through an agglutination reaction, finally forming fibrin polymer with grid structure. The density and viscosity of the reaction system changes drastically during the course of agglutination. In this research, we apply an independently-developed piezoelectric agglutination sensor to detect the fibrinogen agglutination reaction in patients with coronary heart diseases. The terminal judgment method of determining plasma agglutination reaction through piezoelectric agglutination sensor was established. In addition, the standard curve between plasma agglutination time and fibrinogen concentration was established to determinate fibrinogen content quantitatively. The results indicate the close correlation between the STAGO paramagnetic particle method and the method of piezoelectric agglutination sensor for the detection of Fibrinogen. The correlation coefficient was 0.91 (γ = 0.91). The determination can be completed within 10 minutes. The fibrinogen concentration in the coronary heart disease group was significantly higher than that of the healthy control group (P < 0.05). The results reveal that high fibrinogen concentration is closely correlated to the incurrence, development and prognosis of coronary heart diseases. Compared with other traditional methods, the method of piezoelectric agglutination sensor has some merits such as operation convenience, small size, low cost, quick detecting, good precision and the common reacting agents with paramagnetic particle method

    Radiogenomic Analysis of Papillary Thyroid Carcinoma for Prediction of Cervical Lymph Node Metastasis: A Preliminary Study

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    Background Papillary thyroid carcinoma (PTC) is characterized by frequent metastases to cervical lymph nodes (CLNs), and the presence of lymph node metastasis at diagnosis has a significant impact on the surgical approach. Therefore, we established a radiomic signature to predict the CLN status of PTC patients using preoperative thyroid ultrasound, and investigated the association between the radiomic features and underlying molecular characteristics of PTC tumors. Methods In total, 270 patients were enrolled in this prospective study, and radiomic features were extracted according to multiple guidelines. A radiomic signature was built with selected features in the training cohort and validated in the validation cohort. The total protein extracted from tumor samples was analyzed with LC/MS and iTRAQ technology. Gene modules acquired by clustering were chosen for their diagnostic significance. A radiogenomic map linking radiomic features to gene modules was constructed with the Spearman correlation matrix. Genes in modules related to metastasis were extracted for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, and a protein-protein interaction (PPI) network was built to identify the hub genes in the modules. Finally, the screened hub genes were validated by immunohistochemistry analysis. Results The radiomic signature showed good performance for predicting CLN status in training and validation cohorts, with area under curve of 0.873 and 0.831 respectively. A radiogenomic map was created with nine significant correlations between radiomic features and gene modules, and two of them had higher correlation coefficient. Among these, MEmeganta representing the upregulation of telomere maintenance via telomerase and cell-cell adhesion was correlated with 'Rectlike' and 'deviation ratio of tumor tissue and normal thyroid gland' which reflect the margin and the internal echogenicity of the tumor, respectively. MEblue capturing cell-cell adhesion and glycolysis was associated with feature 'minimum calcification area' which measures the punctate calcification. The hub genes of the two modules were identified by protein-protein interaction network. Immunohistochemistry validated that LAMC1 and THBS1 were differently expressed in metastatic and non-metastatic tissues (p=0.003; p=0.002). And LAMC1 was associated with feature 'Rectlike' and 'deviation ratio of tumor and normal thyroid gland' (p<0.001; p<0.001); THBS1 was correlated with 'minimum calcification area' (p<0.001). Conclusions The radiomic signature proposed here has the potential to noninvasively predict the CLN status in PTC patients. Merging imaging phenotypes with genomic data could allow noninvasive identification of the molecular properties of PTC tumors, which might support clinical decision making and personalized management

    Nonlinear Dynamic Characteristic Analysis Method Based on Load Angle of Two-Stage Magnetic Gearbox for Wind Turbine

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    The magnetic gearbox for wind turbine has the potential virtue of less maintenance, improved reliability, and overload protection. Dynamic performance analysis plays a key role in its optimal design and ensuring its stable operation. But so far, there are few unified and effective methods for dynamic performance analysis of magnetic gearbox especially for multistage magnetic gearbox. Thus, a nonlinear dynamic analysis method based on load angle is proposed for two-stage magnetic gearbox in this paper. First, the nonlinear dynamic model of two-stage magnetic gearbox is established based on load angle. Second, the analytical expressions of load angle and magnetic torque of magnetic gearbox facing instantaneous shock are obtained by Taylor expansion based on load angle. Third, the dynamic performance of magnetic gearbox under different operating conditions is analyzed. Finally, the simulation results are discussed, and the results show that the accuracy of the proposed analytical method is comparable to that of Runge-Kutta method, which verifies the effectiveness of the proposed method and facilitates its application to the fast dynamic evaluation and optimal design of multistage magnetic gearbox

    Computational Study on the Catalytic Performance of Single-Atom Catalysts Anchored on g-CN for Electrochemical Oxidation of Formic Acid

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    The electrochemical formic acid oxidation reaction (FAOR) has attracted great attention due to its high volumetric energy density and high theoretical efficiency for future portable electronic applications, for which the development of highly efficient and low-cost electrocatalysts is of great significance. In this work, taking single-atom catalysts (SACs) supported on graphitic carbon nitrides (g-CN) as potential catalysts, their catalytic performance for the FAOR was systemically explored by means of density functional theory computations. Our results revealed that the strong hybridization with the unpaired lone electrons of N atoms in the g-CN substrate ensured the high stability of these anchored SACs and endowed them with excellent electrical conductivity. Based on the computed free energy changes of all possible elementary steps, we predicted that a highly efficient FAOR could be achieved on Ru/g-CN with a low limiting potential of −0.15 V along a direct pathway of HCOOH(aq) → HCOOH* → HCOO* → CO2* → CO2(g), in which the formation of HCOO* was identified as the potential-determining step, while the rate-determining step was located at the CO2* formation, with a moderate kinetic barrier of 0.89 eV. Remarkably, the moderate d-band center and polarized charge of the Ru active site caused the Ru/g-CN catalyst to exhibit an optimal binding strength with various reaction intermediates, explaining well its superior FAOR catalytic performance. Hence, the single Ru atom anchored on g-CN could be utilized as a promising SAC for the FAOR, which opens a new avenue to further develop novel catalysts for a sustainable FAOR in formic-acid-based fuel cells
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