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Highly active Keggin-type silicotungstic acid (SiW12) with oxygen vacancy (Ov) defects was encapsulated into the magnetic floral N-doped carbon microspheres (γ-Fe2O3@NC-300) through the facile one-step air pyrolysis of the precursor comprising core–shell Fe3O4@polydopamine (Fe3O4@PDA) and SiW12 to prepare γ-Fe2O3@NC@SiW12-300. The fabricated catalysts were systematically characterized and subsequently employed for the oxidation desulfurization (ODS) of the model fuel. The magnetic floral γ-Fe2O3@NC@SiW12-300 catalyst exhibited nearly perfect catalytic activity, which under mild conditions could remove 100% amount of 4000 ppm DBT in model fuel within 20 min (0.03 g catalysts and n(H2O2)/n(S) of 2). The catalyst activity is mainly attributed to the high activity SiW12 with the Ov defect and its outstanding dispersibility in γ-Fe2O3@NC, along with the high number of exposed active sites. A selected catalyst, γ-Fe2O3@NC@SiW12-300, showed a noticeable turnover frequency (TOF) (110.07 h−1) and lower activation energy (38.79 kJ mol−1) in oxidative desulfurization (ODS) with good recyclability. HO˙ radical was found to be the active species involved in ODS as confirmed by the EPR and scavenger experiments. Additionally, the fabricated catalyst can be conveniently separated and recycled within an externally applied magnetic field. [ABSTRACT FROM AUTHOR]

Purpose. The stress shielding effect caused due to the mechanical mismatch between the solid titanium and the surrounding bone tissue warrants the utilization of a mechanically and biologically compatible material such as the titanium-hydroxyapatite (Ti-HA) functionally graded material (FGM) for dental implants. This study is aimed at fabricating a Ti-HA FGM with superior mechanical and biological properties for dental implantation. Materials and Methods. We fabricated a Ti-HA FGM with different Ti volume fractions (VFs) using HA and Ti powders. Ti-HA was characterized by studying its mechanical properties. Cytotoxicity was examined using a Cell Counting Kit-8 assay and an LDH cell cytotoxicity assay. Scanning electron microscopy was performed on an XL30 environmental scanning electron microscope (ESEM). Alkaline phosphatase (ALP) and transforming growth factor (TGF-β1) expressions were quantitatively monitored using enzyme-linked immunosorbent assay (ELISA) kits. The expressions of TGF-β receptors and ALP genes were measured using real-time polymerase chain reaction. The Ti-HA FGM dental implants were placed in beagle dogs. Microcomputed tomography (CT) and hard tissue slices were performed to evaluate the bone-implant contact (BIC) and bone volume over total volume (BV/TV). Results. The density and mechanical properties of the Ti-HA exhibited various graded distributions corresponding to VF. Based on the results of the Cell Counting Kit-8 (CCK-8) and lactate dehydrogenase (LDH) assays, the difference in cytotoxicity between the two groups was statistically nonsignificant (P = 0.11). The ALP and TGF-β1 levels were slightly upregulated. The transcript levels of ALP and TGF-βRI were higher in the Ti-HA groups than in the Ti group at 7 days, whereas the transcript levels of TGF-βRII exhibited no obvious increase. The BIC did not exhibit significant differences between the Ti and Ti-HA FGM groups (P = 0.0504). BV/TV showed the Ti-HA FGM group had better osteogenesis (P = 0.04). Conclusion. Ti-HA FGM contributes to the osteogenesis of dental implants in vivo and in vitro. [ABSTRACT FROM AUTHOR]

Dependence of the tribological behaviors of polyimide- and polyetheretherketone-based composites on pv (pressure × speed) factors is investigated in air ambience. It is demonstrated that the hybrid composites filled with nanosilica/carbon fibers/graphite exhibit ultralow friction and wear under extreme conditions. In particular, the friction coefficients of the hybrid nanocomposites at 40 MPa m s−1 are in the range of 0.03-0.04, which are even lower than those obtained with poly alpha olefin lubrication. Moreover, the friction coefficients are lower than those of carbon fibers reinforced polymer composites ever reported in literatures. In order to reveal the underlying mechanisms of ultralow friction and wear, tribochemistry and tribofilms' nanostructures are comprehensively analyzed. It is identified that chelation of polymeric molecular radicals with steel counterface occurs enhancing tribofilm's bonding strength. Striking orientation of the molecules of remnant polymer in tribofilm is indicative that the film exhibits an easy-to-shear characteristic under extreme pv conditions. Nanosilica released onto sliding interface and iron oxide particles abraded from the counterface are thereafter tribosintered into a compact layer, which accounts for the high load-carrying capability of the tribofilm. [ABSTRACT FROM AUTHOR]

Background: No effective treatments have been found for flap necrosis. Animal models that focus on the initial flap viability are inappropriate for necrotic wound studies. Keratinocyte growth factor (KGF) promotes keratinocyte proliferation with stronger activity and fewer complications and thus may be useful for necrotic flap wound healing. Methods: Rats with modified flap necrosis were randomly divided into four groups. An adenoviral vector expressing KGF was injected subdermally in the back of the animals after necrosis began. The expression and effect of KGF was assessed by real-time polymerase chain reaction, enzyme-linked immunoassay, and transwell, and wound healing was monitored. Results: The plasmid and adenovirus were able to express KGF and stimulate epithelial cell growth ( p = 0.029). Histology showed that the necrosis healed fastest in the KGF administration group than in the control groups ( p < 0.01). The adenovirus-mediated KGF (Ad-KGF) group had the thickest epithelium on days 15 ( p = 0.044) and 25 ( p = 0.014). The KGF level in the blood serum soared 10 and 15 days postoperatively ( p < 0.01) but returned to baseline by day 25 ( p = 0.561). The KGF mRNA levels in vivo increased dramatically in the Ad-KGF group ( p = 0.037). Conclusions: The extended flap model is applicable in necrotic wound study. Keratinocyte growth factor can promote secondary necrotic flap wound healing, and administration of KGF can be achieved by an adenoviral vector. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors . [ABSTRACT FROM AUTHOR]

In order to avoid occurrence of severe seizure of motion components exposed to mixed and boundary lubrication, e.g., in engine and transmission systems, to replace metal-metal friction pairs by polymer-metal pairs provides a potential solution. In the present work, the tribological behaviors of short carbon fiber (SCF)-reinforced epoxy (EP) composites when lubricated with polyalphaolefin base oil were investigated. It was identified that the running-in tendency and friction coefficient of the composites show a close dependence on the lubrication regimes. SCF improves greatly the wear resistance of EP although they increase slightly the friction coefficient. It was demonstrated that further addition of monodispersed SiO nanoparticles into the EP composite filled with SCF and graphite leads to higher wear resistance. The reinforcement of SCF and the formation of a high-performance tribofilm on the surface of steel counterpart play an important role on the tribological properties of EP-based materials. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Chemistry is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The chemical and tribological properties of serpentine particles suspended in lubricating oil were investigated using a pin-on-disk high frequency friction machine at 100 °C. The wear scar width of the upper steel pins was measured by an optical microscope. The tribofilm was characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) elemental mapping, and X-ray absorption near-edge structure (XANES) spectroscopy. It was found that the addition of serpentine to commercial engine oil improves its tribological properties. The SEM and EDX elemental mapping shows that a tribofilm formed by the commercial oil with serpentine contains silicon, magnesium, oxygen, phosphorus, sulfur, zinc, calcium, and carbon on the worn surface, which is different from the tribofilm formed by the commercial oil without serpentine. The results of the XANES analysis show that the addition of serpentine to the commercial oil changes the chemical compositions of the tribofilms. This change may account for the better tribological properties of the lubricating oil containing serpentine. The formation mechanism of the tribofilm is discussed. [ABSTRACT FROM AUTHOR]

Antigorite is a Mg-rich 1:1 trioctahedral-structured layered silicate mineral. In recent decades, many studies have been devoted to investigating the tribological performance and application of antigorite as lubrication materials. This article provides an overview of the mineralogy, thermal decomposition and surface modifications of antigorite powders, as well as the recent advancement that has been achieved in using antigorite to reduce friction and wear of friction pairs. The tribological performance of antigorite powders and its calcined product in different lubricating media, such as oil, grease and solid composites have been comprehensively reviewed. The physico-chemical characteristics of surface layers of the friction pairs are discussed. Applications and mechanisms of lubricity and anti-wear of antigorite are highlighted. [ABSTRACT FROM AUTHOR]

Cu(In,Ga)(S,Se)2 (CIGSSe) solar cells are one of the most promising thin film photovoltaics with a record efficiency of 23.6%. However, the biggest drawback to CIGSSe solar cells is their high material cost, partially resulting from relatively rare and expensive indium and gallium. Therefore, improving the utilization of indium and gallium and reducing their wastage can greatly lower the cost of CIGSSe thin film solar cells. Inkjet printing is a facile, cost‐effective, and low‐waste deposition technology, which is particularly suitable for low‐cost and large‐area fabrication of CIGSSe solar cells. Herein, a novel and green ionic liquid‐assisted ink to fabricate highly efficient CIGSSe solar cells is developed. The material utilization of inkjet printing can be remarkably improved compared to the conventional vacuum‐based deposition approach and spin‐coating solution approach. The CIGS printable ink is prepared by dissolving copper acetate, indium acetate, gallium nitrate, and thiourea into ethanol with the assistance of n‐butylammonium butyrate ionic liquid. Ionic liquid‐assisted CIGS ink has a nearly zero wetting angle and a tunable viscosity, which enable to deposit a flat and continuous CIGS thin film by an inkjet printing method. An encouraging power conversion efficiency of 15.22% has been achieved for inkjet‐printed CIGSSe solar cells. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Natural Disasters is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ultra-high speed machining technology enables high efficiency, high precision and high integrity of machined surface. Previous researches of hybrid bearing rarely consider influences of solid particles in lubricant and ultra-high speed of hybrid bearing, which cannot be ignored under the high speed and micro-space conditions of ultra-high speed water-lubricated hybrid bearing. Considering the impact of solid particles in lubricant, turbulence and temperature viscosity effects of lubricant, the influences of particles on pressure distribution, loading capacity and the temperature rise of the lubricant film with four-step-cavity ultra-high speed water-lubricated hybrid bearing are presented in the paper. The results show that loading capacity of the hybrid bearing can be affected by changing the viscosity of the lubricant, and large particles can improve the bearing loading capacity higher. The impact of water film temperature rise produced by solid particles in lubricant is related with particle diameter and minimum film thickness. Compared with the soft particles, hard particles cause the more increasing of water film temperature rise and loading capacity. When the speed of hybrid bearing increases, the impact of solid particles on hybrid bearing becomes increasingly apparent, especially for ultra-high speed water-lubricated hybrid bearing. This research presents influences of solid particles on the loading capacity and the temperature rise of water film in ultra-high speed hybrid bearings, the research conclusions provide a new method to evaluate the influence of solid particles in lubricant of ultra-high speed water-lubricated hybrid bearing, which is important to performance calculation of ultra-high speed hybrid bearings, design of filtration system, and safe operation of ultra-high speed hybrid bearings. [ABSTRACT FROM AUTHOR]

Copyright of Frontiers of Education in China is the property of Higher Education Press Limited Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Corneal decellularization represents a promising alternative source of human donor with global shortage. Multiple methods have been developed for the preparation of decellularized porcine corneal stroma. However, most strategies relied on long-time treatment to facilitate the entry of detergents or nucleases, which may cause irreversible ultrastructural damage. Here, we developed a rapid decellularization method for porcine corneal stroma through the combined mild detergent sodium N-lauroyl glutamate (SLG) and supernuclease. Compared with traditional methods, the novel decellularization method allowed the efficient removal of xenoantigen DNA within 3 h, while retaining the ultrastructure, transparency, and mechanical properties of porcine corneas. When transplanted in rabbit model for 1 month, the decellularized porcine corneal grafts presented favorable transparency and biocompatibility without immune rejection. Therefore, the combined use of detergent SLG and supernuclease may serve as a promising method for the clinical use of decellularized porcine cornea. [ABSTRACT FROM AUTHOR]