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31.
Myoung Su Choi Hyungtaek Jeon Seung-Min Yoo Myung-Shin Lee 《International journal of molecular sciences》2021,22(7)
Exposure to particulate matter (PM) is becoming a major global health issue. The amount and time of exposure to PM are known to be closely associated with cardiovascular diseases. However, the mechanism through which PM affects the vascular system is still not clear. Endothelial cells line the interior surface of blood vessels and actively interact with plasma proteins, including the complement system. Unregulated complement activation caused by invaders, such as pollutants, may promote endothelial inflammation. In the present study, we sought to investigate whether urban PM (UPM) acts on the endothelial environment via the complement system. UPM-treated human endothelial cells with normal human serum showed the deposition of membrane attack complexes (MACs) on the cell surface via the alternative pathway of the complement system. Despite the formation of MACs, cell death was not observed, and cell proliferation was increased in UPM-mediated complement activation. Furthermore, complement activation on endothelial cells stimulated the production of inflammation-related proteins. Our results revealed that UPM could activate the complement system in human endothelial cells and that complement activation regulated inflammatory reaction in microenvironment. These findings provide clues with regard to the role of the complement system in pathophysiologic events of vascular disease elicited by air pollution. 相似文献
32.
Amyloid precursor protein (APP) is a type 1 transmembrane glycoprotein, and its homologs amyloid precursor-like protein 1 (APLP1) and amyloid precursor-like protein 2 (APLP2) are highly conserved in mammals. APP and APLP are known to be intimately involved in the pathogenesis and progression of Alzheimer’s disease and to play important roles in neuronal homeostasis and development and neural transmission. APP and APLP are also expressed in non-neuronal tissues and are overexpressed in cancer cells. Furthermore, research indicates they are involved in several cancers. In this review, we examine the biological characteristics of APP-related family members and their roles in cancer. 相似文献
33.
The role of starch aerogel (St-AG) and carboxymethyl cellulose (CMC) as biolgical active compounds, when they subjected for complexation with metal ions, is assessed in this work. The complexation is carried out with palladium(II) and copper(II) ions, in solid state. Different tools of analysis are carried out to characterize and elucidate the structures of these complexes, namely: elemental analysis, IR, thermal analysis, magnetic measurement and molar conductance techniques. All synthesized complexes are formed with 1:2 (metal:ligand) stoichiometry except the case of aerogel starch 1:1 (Pd:starch). All isolated complexes show a satisfactory cytotoxic effect results against colon cancer cell lines HCT11. Additionally, these complexes are screened for their antibacterial activities against two types of Gram positive and negative bacteria. Molecular docking investigation confirmed the cytotoxicity and antibacterial results. Proton–ligands association constants and their complex formation constants with some bivalent metal ions, using potentiometric method show that the complexes formed in solution have a stoichiometry of 1:1 [metal:ligand]. The effects of metal ion, ionic radius, electronegativity and nature of ligand on the formation constants are discussed. The formation constants of the complexes with 3D transition metals followed the order Mn2+ < Co2+ < Ni2+ < Cu2+ > Zn2+. 相似文献
34.
Present assembly systems are often based on rigid, line-based approaches and are hindered in their reconfiguration capability. Line-less Mobile Assembly Systems (LMAS) are a novel approach for assembly organization. They improve flexibility through mobile resources, permitting spatiotemporal freedom in scheduling and resource assignment. This paper presents a method for a priori assessment of LMAS during the early stages of the assembly system design process. The method applies a modified, extended mean value analysis to a closed queuing network representation of LMAS to estimate performance. The method is validated model analysis and comparison on two use cases indicating plausible model behavior. 相似文献
35.
H. Alrobei M.K. Prashanth C.R. Manjunatha C.B. Pradeep Kumar C.P. Chitrabanu Prasanna D. Shivaramu K. Yogesh Kumar M.S. Raghu 《Ceramics International》2021,47(7):10322-10331
In the present study we made an effort to deploy eco-friendly synthesized reduced graphene oxide/Lanthanum Alluminate nanocomposites (RGO-LaAlO3) and Lanthanum Alluminate (LaAlO3) as adsorbents to remove dye from the synthetic media. XRD, SEM, BET surface area and EDX have been used to characterize the above-mentioned adsorbents. The impacts of different factors like adsorbent dosage, the concentration of adsorbate and PH on adsorption were studied. The best fit linear and nonlinear equations for the adsorption isotherms and kinetic models had been examined. The sum of the normalized errors and the coefficient of determination were used to determine the best fit model. The experimental data were more aptly fitted for nonlinear forms of isotherms and kinetic equations. Pseudo-second-order and Freundlich isotherm model fits the equilibrium data satisfactorily. Methyl orange (MO) has been used as model dye pollutant and maximum adsorption capacity was found to be 469.7 and 702.2 mg g?1 for LaAlO3 and RGO-LaAlO3, respectively. 相似文献
36.
To investigate the evolution of the structural and enhanced magnetic properties of GdMnO3 systems induced by the substitution of Mn with Cr, polycrystalline GdMn1-xCrxO3 samples were synthesized via solid-state reactions. XRD characterization shows that all GdMn1-xCrxO3 compounds with single-phase structures crystallize well and that Cr3+ ions entering the lattice sites of GdMnO3 induce structural distortion. SEM results indicate that the grain size of the synthesized samples (a few microns) decreases as the Cr substitution concentration increases. Positron annihilation lifetime spectroscopy reveals that vacancy-type defects occur in GdMn1-xCrxO3 ceramics and that the vacancy size and concentration clearly change with the Cr content. The temperature and field dependence of the magnetization curves show that Cr substitution significantly influences the magnetic ordering of the gadolinium sublattice, improving the weak ferromagnetic transition temperature and magnetization of GdMn1-xCrxO3. The enhanced magnetization of GdMn1-xCrxO3 is closely related to the vacancy defect concentration. 相似文献
37.
Phuong-Anh Ngoc Doan Tzyi-Horng Tan Lee Fong Siow Beng Ti Tey Eng Seng Chan Teck-Kim Tang Nur Azwani Abdul Karim Eng-Tong Phuah Yee-Ying Lee 《Journal of the American Oil Chemists' Society》2021,98(6):609-620
Palm fatty acid distillate (PFAD) is a rich source of vitamin E. As compared to other vegetable oil, PFAD has higher tocotrienol (70–80%) over tocopherol content, which makes it a valuable source for vitamin E extraction. Current vitamin E extraction methods are not sustainable due to the intensive usage of chemical and high operational cost. Hence, the present study investigated for the first time using dry fractionation process as a green and economical pretreatment method for separating solid fraction (stearin) and liquid fraction (olein) in order to concentrate vitamin E from PFAD in olein fraction. We examined the dry fractionation conditions: crystallization ending temperature (36–44 °C), cooling rate (0.3 and 1.5°C min−1), stirring speed (20–125 rpm), and holding time (0–60 min) on the composition of unsaturated and saturated fatty acids as well as vitamin E content in liquid fraction (olein) and solid fraction (stearin) using gas chromatography and high performance liquid chromatography, respectively. In most of these conditions, vitamin E was ultimately higher in olein fraction as compared to stearin fraction, which is correlated with the high degree of unsaturation. Under a cooling rate of 0.3°C min−1, 90 rpm stirring speed, and ending crystallization of 38 °C, the highest vitamin E rich olein fraction was attained with 1479 ± 10.51 ppm in 50 g olein fraction as compared to 1366 ± 7.94 ppm in 500 g of unfractionated PFAD. 相似文献
38.
Rebecca L. Walton Michael J. Brova Beecher H. Watson Elizabeth R. Kupp Mark A. Fanton Richard J. Meyer Gary L. Messing 《Journal of the European Ceramic Society》2021,41(3):1945-1953
Direct writing is a unique means to align anisotropic particles for the fabrication of textured ceramics by templated grain growth (TGG). We show that alignment of tabular barium titanate (BT) template particles (20–40 μm width and 0.5–2 μm thickness) in a PIN-PMN-PT matrix powder (d50 = 280 nm) is significantly improved during direct writing using anisotropic nozzles at high printing rates. The particle orientation distribution in as-printed filaments, and the texture orientation distribution in sintered ceramic filaments are shown to directly correlate with COMSOL Multiphysics-predicted torque distributions for direct writing with aspect ratio 2, 3 and 5 oval nozzles. Electromechanical strain properties of the textured piezoelectric ceramics significantly improved relative to random ceramics when printed with anisotropic nozzles. Simulations of aspect ratio 20 nozzles and nozzles with interior baffles demonstrate significantly increased torque and near elimination of constant shear stress cores (i.e. plug flow). 相似文献
39.
Sangmin Lee Biao Che Meiling Tai Wanzhao Li Shin-Hyun Kim 《Advanced functional materials》2021,31(42):2105477
Hydrogel shells that compartmentalize the water core from the aqueous surrounding provide molecular selectivity on size and charge in transmembrane transport. It is highly demanding to produce thin hydrogel shells to minimize diffusion length and maximize core volume. Here, internal osmosis in water-in-oil-in-water-in-oil (W/O/W/O) triple-emulsion droplets is used to produce thin hydrogel shells enclosing a large water core. The triple-emulsion droplets are prepared to have an ultrathin middle oil layer using a capillary microfluidic device. The innermost water droplet has a higher osmolarity than the outer water layer containing photopolymerizable hydrogel precursors, which pumps water from the outer layer to the core through the ultrathin oil layer by the osmosis. Therefore, the outer layer gets thinner and hydrogel precursors are enriched while the size of the triple-emulsion droplets remains unchanged. Through photopolymerization of precursors and phase transfer from oil to water, hydrogel shells enclosing water core are produced in the water environment; the oil layer is ruptured for molecular exchange through the shells. The thickness and composition of the hydrogel shells are precisely controllable by the osmotic conditions. The shells show a high permeation rate due to the thinness as well as controlled cut-off threshold of permeation for neutral and charged molecules. 相似文献
40.
Manal A. Mahdy Sayed H. Kenawy Esmat M.A. Hamzawy Gehan T. El-Bassyouni I.K. El Zawawi 《Ceramics International》2021,47(9):12047-12055
The influence of adding 10, 20 and 30% molar ratio of silicon carbide (SiC) separately to a composite of wollastonite (W) with a fixed content of 10%Fe2O3 prepared by wet precipitation method was studied. The crystal structure of the annealed composite powders was inspected by X-ray diffraction (XRD); revealing multi-phase structure. The highest estimated crystallite size investigated by Scherrer equation of W, SiC, WFe:SiC10, WFe:SiC20 and WFe:SiC30 were 53.89, 54.6, 56.3, 48.5 and 54.6 nm respectively; demonstrating the formation of nanocomposites. Particles shape, size and crystallinity of the samples were studied using high resolution transmission electron microscope (HR-TEM). The band gap Eg values of the nanocomposites increased with SiC content having an intermediate value that lies between that of γ-Fe2O3 (maghemite) and SiC. Ferromagnetic and paramagnetic contributions were observed in the magnetic hysteresis loops for the composites. This study highlighted that the coercive field (Hci) of the composites improved with increasing the SiC content. The innovative wollastonite/Fe2O3/SiC with amended magnetic properties elicited attention due to their promising application in bone filler and industrial purposes. 相似文献