Conservative P1 Conforming and Nonconforming Galerkin Fems: Effective Flux Evaluation via a Nonmixed Method Approach

Given a P1 conforming or nonconforming Galerkin finite element method (GFEM) solution ph, which approximates the exact solution p of the diffusion-reaction equation −∇·K∇p + αp = f with full tensor variable coefficient K, we evaluate the approximate flux uh to the exact flux u = −K∇p by a simple but physically intuitive formula over each finite element. The flux is sought in the continuous (in normal component) or the discontinuous Raviart–Thomas space. A systematic way of deriving such a formula is introduced. This direct method retains local conservation property at the element level, typical of mixed methods (finite element or finite volume type), but avoids solving an indefinite linear system. In short, the present method retains the best of the GFEM and the mixed method but without their shortcomings. Thus we view our method as a conservative GFEM and demonstrate its equivalence to a certain mixed finite volume box method. The equivalence theorems explain how the pressure can decouple basically cost free from the mixed formulation. The accuracy in the flux is of first order in the H(div;Ω) norm. Numerical results are provided to support the theory

Die Bewertung von EDV-gestuetzten Produktionsplanungs- und Steuerungssystemen (PPS) aus betriebswirtschaftlicher Sicht

SIGLEBibliothek Weltwirtschaft Kiel A 170177 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Folic acid prevents cardiac dysfunction and reduces myocardial fibrosis in a mouse model of high-fat diet-induced obesity

Abstract Background Folic acid (FA) is an antioxidant that can reduce reactive oxygen species generation and can blunt cardiac dysfunction during ischemia. We hypothesized that FA supplementation prevents cardiac fibrosis and cardiac dysfunction induced by obesity. Methods Six-week-old C57BL6/J mice were fed a high-fat diet (HFD), normal diet (ND), or an HFD supplemented with folic acid (FAD) for 14 weeks. Cardiac function was measured using a transthoracic echocardiographic exam. Phenotypic analysis included measurements of body and heart weight, blood glucose and tissue homocysteine (Hcy) content, and heart oxidative stress status. Results HFD consumption elevated fasting blood glucose levels and caused obesity and heart enlargement. FA supplementation in HFD-fed mice resulted in reduced fasting blood glucose, heart weight, and heart tissue Hcy content. We also observed a significant cardiac systolic dysfunction when mice were subjected to HFD feeding as indicated by a reduction in the left ventricular ejection fraction and fractional shortening. However, FAD treatment improved cardiac function. FA supplementation protected against cardiac fibrosis induced by HFD. In addition, HFD increased malondialdehyde concentration of the heart tissue and reduced the levels of antioxidant enzyme, glutathione, and catalase. HFD consumption induced myocardial oxidant stress with amelioration by FA treatment. Conclusion FA supplementation significantly lowers blood glucose levels and heart tissue Hcy content and reverses cardiac dysfunction induced by HFD in mice. These functional improvements of the heart may be mediated by the alleviation of oxidative stress and myocardial fibrosis

miR-206-3p Inhibits 3T3-L1 Cell Adipogenesis via the c-Met/PI3K/Akt Pathway

MicroRNAs (miRNAs) are important post-transcriptional regulators during adipocyte adipogenesis. MiR-206-3p, a tissue-specific miRNA, is absent in white adipocytes. In this study, we examined the roles of mmu-miR-206-3p in the adipogenic differentiation of 3T3-L1 preadipocytes. The miR-206-3p expression has shown an apparent decreasing trend after induction, and sustained low expression throughout the differentiation of 3T3-L1 cells. miR-206-3p blocked the adipogenic differentiation of 3T3-L1 cells by attenuating c-Met expression; the inhibition effect of miR-206 to the adipogenic differentiation can be counteracted by restoring c-Met expression. In addition, miR-206-3p decreased the phosphorylation of Akt, which is the downstream effector of c-Met in the PI3K/Akt signaling pathway. These data indicate that miR-206-3p inhibits adipocyte adipogenesis through silencing c-Met and subsequently inactivating the PI3K/Akt signaling pathway

Residue of Paclobutrazol and Its Regulatory Effects on the Secondary Metabolites of Ophiopogon japonicas

Currently, paclobutrazol is excessively used in the planting process of Ophiopogon japonicus (O. japonicus) due to its important role in regulating the growth of tuber roots, ultimately increasing the yield and shortening the growth cycle of Ophiopogonis Radix. For insight into this process and the potential risks of paclobutrazol and its mediated consequences on the secondary metabolites in Ophiopogonis Radix, corresponding high performance liquid chromatography-tandem mass spectrometric methods (HPLC-MS/MS) were developed in this study and then applied to Ophiopogonis Radix, soil, and water samples. The results demonstrated the detection of different levels of paclobutrazol residue were in Ophiopogonis Radix, soil, and water samples. In addition, the quantitative results of the secondary metabolites showed that paclobutrazol significantly decreased four steroidal saponins in Ophiopogonis Radix, especially ophiopogonin D, where the content was decreased from 824.87 to 172.50 mg/kg. Concurrently, ophiopogonanone C, a flavonoid in Ophiopogonis Radix, also significantly decreased from 2.66 to 1.33 mg/kg. In conclusion, the residual paclobutrazol and its negative regulation on the secondary metabolism of Ophiopogonis Radix brings potential hazards to the environment and human health. These results provide more comprehensive data that can be used for the reassessment of the use of paclobutrazol in O. japonicus and the formulation of related standards

Source Profiles of Volatile Organic Compounds from Biomass Burning in Yangtze River Delta, China

The volatile organic compounds (VOCs) associated with biomass burning were characterized in the Yangtze River Delta of China, including two types of burning conditions (stove burning and field burning) and five typical kinds of biomass (straws of rice, wheat, bean and rape, and wood). According to the results, the VOC emission factors of straw burning ranged from 2.08 g/kg to 6.99 g/kg with an average of (4.89 +/- 1.70) g/kg, compared to 0.98 g/kg for wood burning. Some differences in VOC composition were observed with the burning of different biomasses. Oxygenated VOC (o-VOC) were the largest contributors to the mass concentration of measured VOCs from straw burning, with a proportion of 49.4%, followed by alkenes 21.4%, aromatics 13.5%, alkanes 10.6% and halogenated VOC (x-VOC) 5.0%. More aromatics and x-VOC were emitted from wood burning compared with straw burning. Field burning emitted more o-VOC due to more air being supplied during the burning test compared with stove burning. Further examination of the detailed VOC species showed the most abundant VOC species from biomass burning were o-VOC, C2-C3 alkenes and C6-C7 aromatics. The ozone formation potential (OFP) of VOCs from straw burning was in the range of 13.92-33.24 g/kg, which was much higher than that of wood burning (4.30 g/kg). Alkenes and o-VOC were the largest contributors to OFP of VOCs from biomass burning. The top five contributors of OFP were ethene, n-hexanal, propylene, acetaldehyde and methyl vinyl ketone, the sum of which accounted for 77% of total OFP. The ratio of ethylbenzene to m,p-xylenes from biomass burning was significantly higher than those from other VOC sources, and thus this could be seen as the fingerprint of biomass burning.Environmental SciencesSCI(E)[email protected]

Dual-Mode Gold Nanocluster-Based Nanoprobe Platform for Two-Photon Fluorescence Imaging and Fluorescence Lifetime Imaging of Intracellular Endogenous miRNA

Bioimaging is widely used in various fields of modern medicine. Fluorescence imaging has the advantages of high sensitivity, high selectivity, noninvasiveness, in situ imaging, and so on. However, one-photon (OP) fluorescence imaging has problems, such as low tissue penetration depth and low spatiotemporal resolution. These disadvantages can be solved by two-photon (TP) fluorescence imaging. However, TP imaging still uses fluorescence intensity as a signal. The complexity of organisms will inevitably affect the change of fluorescence intensity, cause false-positive signals, and affect the accuracy of the results obtained. Fluorescence lifetime imaging (FLIM) is different from other kinds of fluorescence imaging, which is an intrinsic property of the material and independent of the material concentration and fluorescence intensity. FLIM can effectively avoid the fluctuation of TP imaging based on fluorescence intensity and the interference of autofluorescence. Therefore, based on silica-coated gold nanoclusters (AuNCs@SiO2) combined with nucleic acid probes, the dual-mode nanoprobe platform was constructed for TP and FLIM imaging of intracellular endogenous miRNA-21 for the first time. First, the dual-mode nanoprobe used a dual fluorescence quencher of BHQ2 and graphene oxide (GO), which has a high signal-to-noise ratio and anti-interference. Second, the dual-mode nanoprobe can detect miR-21 with high sensitivity and selectivity in vitro, with a detection limit of 0.91 nM. Finally, the dual-mode nanoprobes performed satisfactory TP fluorescence imaging (330.0 μm penetration depth) and FLIM (τave = 50.0 ns) of endogenous miR-21 in living cells and tissues. The dual-mode platforms have promising applications in miRNA-based early detection and therapy and hold much promise for improving clinical efficacy