116 research outputs found

    A Class of Second Order Difference Approximation for Solving Space Fractional Diffusion Equations

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    A class of second order approximations, called the weighted and shifted Gr\"{u}nwald difference operators, are proposed for Riemann-Liouville fractional derivatives, with their effective applications to numerically solving space fractional diffusion equations in one and two dimensions. The stability and convergence of our difference schemes for space fractional diffusion equations with constant coefficients in one and two dimensions are theoretically established. Several numerical examples are implemented to testify the efficiency of the numerical schemes and confirm the convergence order, and the numerical results for variable coefficients problem are also presented.Comment: 24 Page

    NO Reduction By Propane Over Monolithic Cordierite-based Fe/Al2O3 Catalyst: Reaction Mechanism And Effect Of H2O/SO2

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    The selective reduction of NO by C3H8and the sensitivity to H2O and SO2have been studied over monolithic cordierite-based Fe/Al2O3catalysts, which were prepared by the sol–gel and impregnation method. The catalysts were investigated by N2 adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. Results showed that NO reduction was more than 90% in the absence of oxygen at 500 °C and in the presence of oxygen at 600 °C respectively. In a continues test of 12 h at 600 °C, 0.02% of SO2caused an irrecoverable decrease of NO conversion from 94% to 85% and 2.5% of H2O caused a drop of NO conversion from 86% to 56%, while NO conversion totally recovered when H2O was removed. The catalysts lost 15% of the initial activity after a hydrothermal treatment due to the agglomeration of iron oxide nanorods. Sulphidation treatment caused about a loss of 30% of the initial activity because of the deposited SO42−species. In situ study by DRIFTS indicated that coexisting H2O influenced the formation NO2 ad species and unidentate nitrate, while SO2 slightly inhibited the formation of NO2/NO3−species but promoted the formation of acetate/formate species during NO reduction by C3H8. Based on the results, a preliminary mechanism was proposed and discussed. The results may help understand the fundamental performance of monolithic cordierite-based Fe/Al2O3catalysts and provide some reference for SCR-HC catalyst design

    Upconversion NIR-II fluorophores for mitochondria-targeted cancer imaging and photothermal therapy

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    Acknowledgements: The work was supported by the National Key R&D Program of China (2020YFA0908800), NSFC (81773674, 81573383), Shenzhen Science and Technology Research Grant (JCYJ20190808152019182), Hubei Province Scientific and Technical Innovation Key Project, National Natural Science Foundation of Hubei Province (2017CFA024, 2017CFB711), the Applied Basic Research Program of Wuhan Municipal Bureau of Science and Technology (2019020701011429), Tibet Autonomous Region Science and Technology Plan Project Key Project (XZ201901-GB-11), the Local Development Funds of Science and Technology Department of Tibet (XZ202001YD0028C), Project First-Class Disciplines Development Supported by Chengdu University of Traditional Chinese Medicine (CZYJC1903), Health Commission of Hubei Province Scientific Research Project (WJ2019M177, WJ2019M178), the China Scholarship Council, and the Fundamental Research Funds for the Central Universities.Peer reviewedPublisher PD

    Novel NIR-II organic fluorophores for bioimaging beyond 1550 nm

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    This work was partially supported by grants from NSFC (81773674, 81573383, and 21473041), NSFHP (2017CFA024, 2017CFB711, and 2016ACA126), the Applied Basic Research Program of WMBST (2019020701011429), Tibet Autonomous Region Science and Technology Plan Project Key Project (XZ201901-GB-11), Project First-Class Disciplines Development Supported by Chengdu University of Traditional Chinese Medicine (CZYJC1903), and Health Commission of Hubei Province Scientific Research Project (WJ2019M177 and WJ2019M178).Peer reviewedPublisher PD

    Brachial-ankle pulse wave velocity trajectories in a middle-aged population

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    ObjectiveThe “trajectory” phenotype was observed in several cardiovascular risk factors with aging. We aim to identify multiple brachial-ankle Pulse Wave Velocity (baPWV) trajectory phenotypes and assess their determinants.MethodsAmong 5,182 participants with baPWV measurements (2010–2016) at no less than three time points in Kailuan Study, we derived baPWV trajectory pattern using SAS Proc Traj program. We applied the lowest Bayesian information criterion to identify the best typing model, related the identified trajectory pattern to baseline and changes in characteristics.ResultsAmong 5.3 ± 1.7 years follow-up, four distinct baPWV trajectories were identified as low (1,961,37.8%), medium-low (1,846,35.6%), medium-high (1,024,19.8%), and high (351,6.8%) groups. In the stepwise models, mean arterial pressure and age were the main determinators of the trajectory patterns, with a Δpseudo-R2 of 0.335 and 0.164, respectively. With the low trajectory group as reference and multivariable adjustment, odd ratios of medium low, medium high and high associated with 1 mmHg increment of mean arterial pressure were 1.08(95%CI: 1.07–1.09), 1.13(1.12–1.14), and 1.16(1.15–1.18). The estimates for age were 1.08(1.07–1.10), 1.20(1.18–1.21) and 1.28(1.26–1.31). Additionally, baseline resting heart rate, low-density lipoprotein cholesterol, fasting blood glucose, hypersensitive C-reaction protein and uric acid, and changes in mean arterial pressure, resting heart rate, fasting blood glucose, and uric acid were positively associated with the trajectory, while BMI was negatively associated.ConclusionsThe changes in baPWV overtime followed a “trajectory” pattern, mainly determined by mean arterial pressure and age

    Radiosensitizing effects of Sestrin2 in PC3 prostate cancer cells

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    Objective(s): The stress-responsive genes of Sestrin family are recognized as new tumor suppressor genes in breast carcinoma, however, the function of Sestrin family in human prostate cancer is not clear. Ionizing radiation (IR) is known to induce Sestrin gene expression in breast cancer cells. However, the response of Sestrin to IR has not been reported in PC3 prostate cancer cells. Materials and Methods: Sestrin2 expression in prostate cancer cell lines (PC3, LNCaP clone FGC, and DU145) was detected by Western blot and real-time PCR. Cell counting kit (CCK-8) was used to detect cellular proliferation. The radiosensitivity of PC3 cells was detected by clonogenic assay. Results: Sestrin2 expression in prostate cancer cell lines (PC3, LNCaP clone FGC, and DU145) is low. In vitro assays indicated that over-expressing Sestrin2 in human prostate cancer PC3 inhibited tumor proliferation. In addition, elevated Sestrin2 expression sensitized PC3 cells to IR. Conclusion: We determined Sestrin2 may function as a tumor suppressor through repressing proliferation, mediating sensitization to IR in PC3 cells

    Associations of Pulmonary Fibrosis with Peripheral Blood Th1/Th2 Cell Imbalance and EBF3 Gene Methylation in Uygur Pigeon Breeder’s Lung Patients

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    Background/Aims Pigeon breeder’s lung (PBL) results from Th1/Th2 cell imbalance. B cells inhibit the immune activity of Th1, and EBF3 is a key B cell factor. This study explored the relationship between EBF3 and Th1/Th2 imbalance in chronic PBL cases complicated with pulmonary fibrosis (PF). Methods Twenty Uygur PBL+PF patients, 20 pigeon breeders without PBL or PF, and 20 healthy individuals without pigeon breeding history constituted the patient I, negative control, and normal control groups, respectively. Peripheral blood specimens and case backgrounds were collected between June 2016 and March 2017. EBF3 gene methylation was analyzed by matrix assisted laser desorption ionization-time of flight mass spectrometry. To compare different mechanisms of PF progression in PBL, samples from 20 Uygur PBL patients without PF (at acute and sub-acute stages) were collected between October 2017 and February 2018, constituting the patient II group. EBF3 mRNA expression was evaluated by real-time polymerase chain reaction. IFN-γ, IL-4 and IL-10 expression and Th1/Th2 imbalance in PBL were evaluated by enzyme-linked immunosorbent assay and flow cytometry. Results CpG-2 and general methylation rates in the patient I group were lower than those in the control groups (P˂0.017). The level of EBF3 mRNA expression in the patient I group was significantly higher than that in any other group. Compared with the control groups, the patient I group showed a significantly higher level of IL-4, whereas the patient II group showed a significantly lower level. IL-10 was also expressed more highly in the patient I group than in any other group (P< 0.01). Flow cytometry showed INF-γ dominance (Th1 cytokine) in PBL at the acute/sub-acute stage and IL-4 dominance (Th2 cytokine) at the chronic stage after PF occurred. The general methylation rate was negatively correlated with the mRNA level, with the latter being positively correlated with the IL-10 level and number of pigeons bred in the past 3 months. IL-4 expression was negatively correlated with INF-γ but positively correlated with PF area and duration of pigeon breeding history. Conclusions After PF occurs in chronic PBL, the inflammation type changes from Th1 dominance to Th2 dominance. During PBL development, IL-10 increases before IL-4 does, which may be associated with EBF3 hypomethylation and the involvement of B lymphocytes
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