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排序方式: 共有262条查询结果,搜索用时 0 毫秒
1.
Locke Davenport Huyer Serena Mandla Yufeng Wang Scott B. Campbell Bess Yee Christian Euler Benjamin F. Lai A. Dawn Bannerman Dawn S. Y. Lin Miles Montgomery Kayla Nemr Timothy Bender Slava Epelman Radhakrishnan Mahadevan Milica Radisic 《Advanced functional materials》2021,31(6):2003341
Itaconate (ITA) is an emerging powerhouse of innate immunity with therapeutic potential that is limited in its ability to be administered in a soluble form. A library of polyester materials that incorporate ITA into polymer backbones resulting in materials with inherent immunoregulatory behavior is developed. Harnessing hydrolytic degradation release from polyester backbones, ITA polymers result in the mechanism specific immunoregulatory properties on macrophage polarization in vitro. In a functional assay, the polymer-released ITA inhibits bacterial growth on acetate. Translation to an in vivo model of biomaterial associated inflammation, intraperitoneal injection of ITA polymers demonstrate a rapid resolution of inflammation in comparison to a control polymer silicone, demonstrating the value of sustained biomimetic presentation of ITA. 相似文献
2.
Asymmetric horizontal thermal profiles can change the flow field structure in the physical vapor transport (PVT)of Hg2Cl2. It is found that for the ratios of horizontal to vertical thermal Rayleigh numbers RaH/Ra ≥ 1·5, the convetive flow structure changes from multicellular to unicellular for the base parametric state of Ra = 2·79 × 104, Pr = 0·91, Le=l·01. Pe = 4·60, Ar= 0·2 and Cr = 1·01. The unicellular flow structure obtained by increasing ∇*H(RaH) is not likely to support the conjecture of the presence of unicellular convective mode in the laser Doppler velocimetry (LDV) experiments for PVT process of Hg2Cl2 (Kim el al., 1996). When the six parameters of Ra, Pr, Le, Pe, Ar and Cr are fixed, the dimensional maximum magnitude of the velocity vector |U|max is proportional to √∇T*H. 相似文献
3.
Mickaël Duval Jean-Charles Passieux Michel Salaün Stéphane Guinard 《Archives of Computational Methods in Engineering》2016,23(1):17-38
This paper provides a detailed review of the global/local non-intrusive coupling algorithm. Such method allows to alter a global finite element model, without actually modifying its corresponding numerical operator. We also look into improvements of the initial algorithm (Quasi-Newton and dynamic relaxation), and provide comparisons based on several relevant test cases. Innovative examples and advanced applications of the non-intrusive coupling algorithm are provided, granting a handy framework for both researchers and engineers willing to make use of such process. Finally, a novel nonlinear domain decomposition method is derived from the global/local non-intrusive coupling strategy, without the need to use a parallel code or software. Such method being intended to large scale analysis, we show its scalability. Jointly, an efficient high level Message Passing Interface coupling framework is also proposed, granting an universal and flexible way for easy software coupling. A sample code is also given. 相似文献
4.
5.
D. M. Allen H. J. Almond K. Bedner M. Cabeza B. Courtot A. Duval S. A. Impey M. Saumer 《Microsystem Technologies》2009,15(8):1287-1291
The objective of this research was to study the influence of electroplating parameters on electrodeposit characteristics for
the production of nickel (Ni) and nickel–iron (Ni–Fe) microparts by photoelectroforming. The research focused on the most
relevant parameter for industry, which is the current density, because it determines the process time and the consumed energy.
The results of the Ni and Ni–Fe characterisations can be divided into two aspects closely linked with each other: the morphology
and the hardness. 相似文献
6.
Clémence Demangel Delphine Auzène Muriel Vayssade Jean-Luc Duval Pascale Vigneron Marie-Danièle Nagel Jean-Claude Puippe 《Materials science & engineering. C, Materials for biological applications》2012,32(7):1919-1925
Metal injection molding (MIM) is a near net shape manufacturing method that allows for the production of components of small to moderate size and complex shape. MIM is a cost-effective and flexible manufacturing technique that provides a large innovative potential over existing methods for the industry of implantable devices. Commercially pure titanium (CP-Ti) samples were machined to the same shape as a composite feedstock with titanium and polyoxymethylene, and these metals were injected, debinded and sintered to assess comparative biological properties. Moreover, we treated MIM-Ti parts with BIOCOAT®, BIODIZE® and BIOCER®, three different anodic oxidation techniques that treat titanium using acid, alkaline and anion enriched electrolytes, respectively. Cytocompatibility as well as morphological and chemical features of surfaces was comparatively assessed on each sample, and the results revealed that MIM-Ti compared to CP-Ti demonstrated a specific surface topography with a higher roughness. MIM-Ti and BIOCER® samples significantly enhanced cell proliferation, cell adhesion and cell differentiation compared to CP-Ti. Interestingly, in the anodization post-treatment established in this study, we demonstrated the ability to improve osseointegration through anionic modification treatment. The excellent biological response we observed with MIM parts using the injection molding process represents a promising manufacturing method for the future implantable devices in direct contact with bones. 相似文献
7.
Effects of ethyl-3-nitrooxy propionate and 3-nitrooxypropanol on ruminal fermentation,microbial abundance,and methane emissions in sheep 总被引:1,自引:0,他引:1
G. Martínez-Fernández L. Abecia A. Arco G. Cantalapiedra-Hijar A.I. Martín-García E. Molina-Alcaide M. Kindermann S. Duval D.R. Yáñez-Ruiz 《Journal of dairy science》2014
The aim of this work was to investigate the effect of feeding ethyl-3-nitrooxy propionate (E3NP) and 3-nitrooxypropanol (3NP), 2 recently developed compounds with potential antimethanogenic activity, in vitro and in vivo in nonlactating sheep on ruminal methane production, fermentation pattern, the abundance of major microbial groups, and feed degradability. Three experiments were conducted, 1 in vitro and 2 in vivo. The in vitro batch culture trial (experiment 1) tested 2 doses of E3NP and 3NP (40 and 80 μL/L), which showed a substantial reduction of methane production (up to 95%) without affecting concentration of volatile fatty acids (VFA). The 2 in vivo trials were conducted over 16 d (experiment 2) and 30 d (experiment 3) to study their effects in sheep. In experiment 2, 6 adult nonpregnant sheep, with permanent rumen cannula and fed alfalfa hay and oats (60:40), were treated with E3NP at 2 doses (50 and 500 mg/animal per day). After 7, 14, and 15 d of treatment, methane emissions were recorded in respiration chambers and rumen fluid samples were collected for VFA analysis and quantification of bacterial, protozoal, and archaeal numbers by real-time PCR. Methane production decreased by 29% compared with the control with the higher dose of E3NP on d 14 to 15. A decrease in the acetate:propionate ratio was observed without detrimental effects on dry matter intake. In experiment 3, 9 adult nonpregnant sheep, with permanent rumen cannula and fed with alfalfa hay and oats (60:40), were treated with E3NP or 3NP at one dose (100 mg/animal per day) over 30 d. On d 14 and d 29 to 30, methane emissions were recorded in respiration chambers. Rumen fluid samples were collected on d 29 and 30 for VFA analysis and quantification of bacterial, protozoal, and archaeal numbers by real-time PCR. In addition, on d 22 and 23, samples of oats and alfalfa hay were incubated in the rumen of sheep to determine dry matter ruminal degradation over 24 and 48 h, respectively; no effect was observed (78.6, 78.3, and 78.8% of alfalfa and 74.2, 74.0, and 70.6% of oats in control, E3NP, and 3NP groups, respectively). A reduction in methane production was observed for both additives at d 14 and d 29 to 30. In both treatments, the acetate:propionate ratio was significantly decreased. Likewise, total concentrations of the analyzed microbial groups in the rumen showed no difference among treatments and doses for both experiments. Both tested compounds showed promise as methane inhibitors in the rumen, with no detrimental effects on fermentation or intake, which would need to be confirmed in lactating animals. 相似文献
8.
Ni-based superalloy Inconel 617 (IN617) is one of the main candidate structural materials for high temperature components (heat exchanger) of the gas-cooled fast reactor (GFR), a possible candidate for generation IV nuclear reactor. The material in operating conditions will be exposed to impure He at a temperature of around 850 °C. The impurities are expected to be oxidizing (such as O2, H2O) but since no feedback experience is available for this type of reactor, the level of impurities is completely unknown. Hence, an attempt has been made to understand the influence of oxygen partial pressure on oxide composition and on the oxidation mechanisms of IN617 at 850 °C. To achieve this, oxidation tests were performed at 3 different range of partial pressure: 10?5, 0.2 and 200 mbar. Tests were performed from 1 h to 28 days and the obtained oxide layers were characterized using MEB, EDX, XPS, XRD and GD-OES. The oxide layers were mainly composed of chromia containing TiO2 and thickening with time. Aluminium oxide formed internally. Other oxides were detected in the scale, such as NiO, CoO, MoO3 and MnO2, except for the lowest oxygen partial pressure experiments, where a selective oxidation took place. The scale-growth mechanism was cationic for low and medium oxygen partial pressure conditions. A growth following a transient oxidation mechanism was observed for high oxygen partial pressure. 相似文献
9.
Dynamic mechanical analysis of the multiple glass transitions of plasticized wheat gluten biopolymer 下载免费PDF全文
Glass transition of thermo‐molded biomaterials made from wheat gluten and its main protein classes is studied by dynamic mechanical analysis (DMA). The materials are plasticized with variable contents of glycerol (30–40 wt %) and water (0–20 wt %). For all materials, three successive relaxation phases are systematically detected. Their positions shift to lower temperature as the plasticizer content of materials increases. Composition in gluten, glycerol and water of each relaxation phase is estimated using the Couchman‐Karasz model. Irrespective of the plasticizer content or composition, the relaxation phases shows rather constant plasticizer volume fractions. The low‐, middle‐, and high relaxation phases include respectively around 30, 60 and 80 vol % of gluten protein. These relaxations are assigned to the segmental motion of the surface amino‐acid side groups, to the collective motion of packed gluten proteins, and to the gain in protein conformational mobility as a 2D network of interacting plasticizer molecules forms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43254. 相似文献
10.
The chromatographic analysis of resol solutions in tetrahydrofuran solvent, by means of a set of columns packed with crosslinked polystyrene gels, has been carried out with adequate resolving power for a clear-cut qualitative or semiquantitative differentiation between various types of resols to be practicable. The resulting chromatograms, which show the distribution of different constituents by molecular size, could be interpreted by the use of reference substance and by calibrating the system with a number of compounds of known structures. The method has been used to investigate the way in which various reaction parameters (nature of catalysts, proportion of starting material, treatments undergone by the resols) affect the composition of resols. Different commercial products have been thus characterized. It has also afforded an insight into the progress of the polycondensation reaction as a function of time and helped to state the reactivity of different groups and unblocked ring positions. Thus, an hydroxymethyl group appears to be more reactive in the para than in the ortho position. Otherwise the reactivity of unblocked ring positions would be enhanced by an hydroxymethyl group in the ortho rather than para position. 相似文献