A model study of a folded plate structure

Call number: LD2668 .T4 1969 C42Master of Scienc

Biological Detoxification of Mercury Contaminated Soil

This study examined biological mercury removal from soil using mercury-resistant bacteria in soil microcosms. Mercuric chloride was used to artificially contaminate Kidman soil to mercury concentrations of 5 ppm and 10 ppm. Soil moisture content was maintained at three levels, 20%, 30% and 50%. Mercury resistant-bacteria were added to soil samples and the mercury removal rate was compared to control samples without added bacteria. Mercury removal rate was initially enhanced by the addition of bacteria. After 30 days, no difference was observed between samples and controls with initial mercury concentration of 5 ppm when soil moisture content was 20%. At an initial mercury concentration of 10 ppm, soil samples had less mercury remaining than controls after 30 days. Autoclaved soil had a decreased mercury removal rate compared to soil not autoclaved. Addition of nutrient (sucrose) did not increase the mercury removal rate. A slurry-type bioreactor was found to be more efficient than a non-stir type. After 30 days of continuous stirring, 85-90% of the added mercury (10 ppm) was removed, while under the same conditions except no stirring, only around 60% of the mercury was removed. Overall, biological detoxification of mercury from contaminated soil can be achieved by using a slurry-type bioreactor with addition of mercury-resistant bacteria

#12 - Electronic Cigarettes Induce Chronic Obstructive Pulmonary Disease in a Pre-Clinical Model

Background: Chronic obstructive pulmonary disease (COPD) is currently listed as the 4th leading cause of death and is projected to be the 3rd leading cause of death by 2020. Cigarette smoking is considered to be the leading cause of COPD in the developed world; however, with the emerging popularity of electronic cigarettes (e-cigarettes), the impact of e-cigarette vapor on the development of COPD requires further attention. COPD is characterized by limitations in expiratory airflow, emphysematous destruction of the lungs, bronchitis, and chronic inflammation of the lung tissue. Most of the e-cigarettes are introduced as a healthier tool to help people to quit the traditional cigarette. This is a device that effectively transports evaporated liquid nicotine to the lungs. Users can choose the nicotine concentration of the e-cigarette liquid (e-liquid) that loaded into the device\u27s cartridge. When inhaled, the e-liquids (nicotine) is heated to produce vapor that enters the lungs. Hypothesis: We hypothesized that nicotine-containing e-cigarettes induce the exacerbation of COPD in a pre-clinical model. Methods: Twenty Scnn1b-Tg+ mice were exposed to nicotine-containing e-cigarette vapor for ten days, each mice was exposed two hours per day. This transgenic animal model exhibits mucus hypersecretion and defective mucus clearance in the lung closely mimicking human COPD onset and progression. After treatment, bronchoalveolar lavage (BAL) fluid, lung tissues, and serum were collected to assess for inflammation, fibrosis, and mucus accumulation. Results: Inflammatory cytokines such as CXCL1, MMP-2, and CX3CL1 concentrations were significantly higher in animals exposed to e-cigarette vapor. Moreover, e-cigarette exposure increased mucus accumulation and fibrosis production in the bronchioles of the Scnn1b-Tg+ mice. Conclusion: These results suggest that nicotine-containing e-cigarette vapor induce the exacerbation of COPD in our animal model. Future studies will focus on chronic exposure of e-cigarette vapor to evaluate the mechanism of nicotine-containing e-cigarettes on the pathogenesis of COPD

Effect of the Steam Activation Thermal Treatment on the Microstructure of Continuous TiO 2

The continuous TiO2 fibers have been synthesized by the sol-gel method using the polymer of titanate as the precursor solution. The as-synthesized samples were characterized using XRD, SEM, and HR-TEM analysis methods. The grain growth kinetics was primarily investigated. The results demonstrated that the average diameters of the fibers were in the range of 20–30 μm, the crystal phase of the synthesized TiO2 fiber was transformed from anasate to rutile, and the crystal size became bigger with increasing the temperature using steam activation. The growth exponent and the constant of growth rate of the rutile crystal phase at 500°C were 4 and 2.55×106 nm/h, respectively. The activation energies of crystalline growth during 500°C~700°C and 700°C~800°C were 38.62 kJ/mol and 143.91 kJ/mol, respectively

Rspo1/Rspo3‐LGR4 signaling inhibits hepatic cholesterol synthesis through the AMPKα‐SREBP2 pathway

R‐spondins (Rspos) are endogenous ligands of leucine‐rich repeat‐containing G‐protein‐coupled receptor 4 (LGR4). Rspos‐LGR4 signaling plays important roles in embryogenesis, gastrointestinal homeostasis, and food intake. Here, we investigated the impacts of Rspos‐LGR4 on hepatic cholesterol synthesis. Rspo1/3 and Lgr4 knockdown mice were used to investigate the impacts of Rspo1/3‐LGR4 on hepatic cholesterol synthesis. AMPKα agonist, antagonist, and shRNA were used to explore the downstream targets of Rspos‐LGR4 signaling. In our study, we reported that LGR4, Rspo1, and Rspo3 were highly expressed in hepatocytes and their expressions were sensitive to energy states. Rspo1 and Rspo3 reversed OA‐induced cholesterol synthesis, accompanying with increased the phosphorylation of AMPKα Thr172, reduced SREBP2 nuclear translocation, and Srebf2 mRNA expression. Conversely, hepatic LGR4 knockdown increased hepatic cholesterol synthesis and decreased the phosphorylation of AMPKα both in vitro and in vivo. Activation or inhibition of AMPKα significantly abolished the effects of LGR4 deficiency or Rspos, respectively, on cholesterol synthesis. Knockdown of AMPKα1 or/and AMPKα2 repressed Rspos‐induced inhibition on cholesterol synthesis. Our study indicates that Rspo1/Rspo3‐LGR4 signaling in hepatocytes suppresses cholesterol synthesis via the AMPKα‐SREBP2 pathway.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163398/2/fsb221026.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163398/1/fsb221026_am.pd

Rarefication effects on jet impingement loads

Rarefication effects on jet impingement loads are studied by comparing recent new formulas at the collisionless flow limit and numerical simulations. The jet exit size is finite, and can be either planar or round. In the simulations, the jets have different degrees of rarefication, with a Knudsen (Kn) number ranging from 0 to infinity; i.e., the jet flows can be continuum, collisional, or collisionless. The comparison results indicate that (1) the new surface load formulas are accurate at the collisionless flow limit; (2) in general, the formulas offer upper limits for the peak loads; (3) however, it is improper to assert that local loads always decrease. The new formulas can offer fast estimations of impingement loads. This may be quite helpful for applications in space engineering by significantly reducing the amount of simulations and experiment costs. Those expressions explicitly include non-dimensional parameters, and their contribution and influence on the loads can be studied in a systematic manner (e.g., with a swift parameter study)

Indium-Containing Visible-Light-Driven (VLD) Photocatalysts for Solar Energy Conversion and Environment Remediation

Indium-containing visible-light-driven (VLD) photocatalysts including indium-containing oxides, indium-containing sulfides, indium-containing hydroxides, and other categories have attracted more attention due to their high catalytic activities for oxidation and reduction ability under visible light irradiation. This chapter will therefore concentrate on indium-containing nano-structured materials that demonstrate useful activity under solar excitation in fields concerned with the elimination of pollutants, partial oxidation and the vaporization of chemical compounds, water splitting, and CO2 reduction processes. The indium-containing photocatalysts can extend the light absorption range and improve the photocatalytic activity by doping, heterogeneous structures, load promoter, and morphology regulation. A number of synthetic and modification techniques for adjusting the band structure to harvest visible light and improve the charge separation in photocatalysis are discussed. In this chapter, preparation, properties, and potential applications of indium-containing nano-structured materials used as photocatalysis will be systematically summarized, which is beneficial for understanding the mechanism and developing the potential applications

Arctigenin-induced reversal of drug resistance in cisplastin-resistant cell line A549/DDP, and the mechanism involved

Purpose: To investigate the drug resistance reversal effect of arctigenin (ARG) on cisplatin-insensitive A549/DDP cancer cells, and to elucidate the underlying mechanism(s). Methods: Four groups of cells: control, DDP, ARG and ADP were used. The degrees of inhibition of proliferation, drug resistance and apoptotic changes were measured using MTT assay, CCK-8 assay and flow cytometry, respectively. Expressions of PTEN and STAT3 proteins were determined by Western blotting. Results: At ARG concentration of 5 μmol/L, A549/DDP cells were significantly inhibited (p < 0.05). The combination therapy was more effective in reversing A549/DDP cells resistance than the single therapy. The expression level of PTEN protein increased with increase in ARG concentration, while STAT3 protein expression decreased with increase in ARG concentration. ADP group up-regulated PTEN but decreased STAT3 expression levels. Conclusion: ARG regulates drug resistance in A549/DDP cells, possibly via a mechanism involving reduction of A549/DDP cell sensitivity to DDP, thereby regulating the stress pathways associated with PTEN and STAT3. The combination of ARG and DDP effectively reduces A549/DDP cells resistance

Analysis of a stochastic delay competition system driven by Lévy noise under regime switching

This paper is concerned with a stochastic delay competition system driven by Lévy noise under regime switching. Both the existence and uniqueness of the global positive solution are examined. By comparison theorem, sufficient conditions for extinction and non-persistence in the mean are obtained. Some discussions are made to demonstrate that the different environment factors have significant impacts on extinction. Furthermore, we show that the global positive solution is stochastically ultimate boundedness under some conditions, and an important asymptotic property of system is given. In the end, numerical simulations are carried out to illustrate our main results

High glucose-induced Matrilin-2 expression in mouse mesangial cells was mediated by transforming growth factor beta 1 (TGF-β1)

This study aimed at evaluating the effect of high glucose on the expression of extracellular matrix (ECM) protein Matrilin-2 and the mechanism underlying this effect by using a mouse mesangial cell line. Mouse mesangial cells (MMCs) were cultured in media containing normal (5 mM d-glucose) or high concentrations of glucose (30 mM d-glucose). The expression of Matrilin-2 was assessed by either RT-PCR or western blot. Additionally, transforming growth factor beta 1 (TGF-β1) inhibitors and TGF-β1 were used to determine whether glucose-regulated Matrilin-2 expression was mediated by the TGF-β1/Smad3 signaling pathway. Our data demonstrated that Matrilin-2 expression was markedly induced by high glucose and TGF-β1. High glucose-induced Matrilin-2 expression was inhibited by TGF-β1/Smad3 inhibitors, indicating that Matrilin-2 was markedly induced by high glucose and this induction was mediated by the TGF-β1/Smad3 pathway. Taken together, our results showed that high-glucose-induced Matrilin-2 expression that was mediated by the TGF-β1/Smad3 signaling pathway might play a role in Diabetic nephropathy (DN) pathogenesis and our finding provided a potential diagnostic and/or therapeutic target for DN