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排序方式: 共有408条查询结果,搜索用时 15 毫秒
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2.
Changmo Kim Izhar Livne‐Bar Karsten Gronert Jeremy M. Sivak 《Molecular nutrition & food research》2020,64(4)
Lipoxins (LXs) are autacoids, specialized proresolving lipid mediators (SPMs) acting locally in a paracrine or autocrine fashion. They belong to a complex superfamily of dietary small polyunsaturated fatty acid (PUFA)–metabolites, which direct potent cellular responses to resolve inflammation and restore tissue homeostasis. Together, these SPM activities have been intensely studied in systemic inflammation and acute injury or infection, but less is known about LX signaling and activities in the central nervous system. LXs are derived from arachidonic acid, an omega‐6 PUFA. In addition to well‐established roles in systemic inflammation resolution, they have increasingly become implicated in regulating neuroinflammatory and neurodegenerative processes. In particular, chronic inflammation plays a central role in Alzheimer's disease (AD) etiology, and dysregulated LX production and activities have been reported in a variety of AD rodent models and clinical tissue samples, yet with complex and sometimes conflicting results. In addition, reduced LX production following retinal injury has been reported recently by the authors, and an intriguing direct neuronal activity promoting survival and homeostasis in retinal and cortical neurons is demonstrated. Here, the authors review and clarify this growing literature and suggest new research directions to further elaborate the role of lipoxins in neurodegeneration. 相似文献
3.
Recent progress in road and lane detection: a survey 总被引:2,自引:0,他引:2
The problem of road or lane perception is a crucial enabler for advanced driver assistance systems. As such, it has been an active field of research for the past two decades with considerable progress made in the past few years. The problem was confronted under various scenarios, with different task definitions, leading to usage of diverse sensing modalities and approaches. In this paper we survey the approaches and the algorithmic techniques devised for the various modalities over the last 5 years. We present a generic break down of the problem into its functional building blocks and elaborate the wide range of proposed methods within this scheme. For each functional block, we describe the possible implementations suggested and analyze their underlying assumptions. While impressive advancements were demonstrated at limited scenarios, inspection into the needs of next generation systems reveals significant gaps. We identify these gaps and suggest research directions that may bridge them. 相似文献
4.
Summary Swelling equilibrium of polyelectrolyte copolymer gels containing of acrylamide (AAm) and 2-acrylamido-2-methyl-1-propanesulfonic
acid sodium salt (AMPS) have been studied as a function of copolymer composition. AAm/AMPS hydrogels were prepared by free
radical solution polymerization in aqueous solution of AAm with AMPS as anionic comonomer and two multifunctional crosslinkers
such as ethylene glycol dimethacrylate (EGDMA) and trimethylolpropane triacrylate (TMPTA). Swelling experiments were performed
in water at 25 °C, gravimetrically. The influence of AMPS content in hydrogels was examined. Swelling of AAm/AMPS hydrogels
was increased up to 1018% (for containing 2% AMPS and crosslinked by EGDMA) 15246% (for containing 8% AMPS and crosslinked
by TMPTA), while AAm hydrogels swelled up to 804% (crosslinked by TMPTA)–770% (crosslinked by EGDMA). The values of equilibrium
water content of the hydrogels are 0.8851–0.9935. Diffusion behavior was investigated. Water diffusion into hydrogels was
found to be non-Fickian in character. 相似文献
5.
In this paper, we propose two dynamic lead-time quotation policies in an M/GI/1 type make-to-stock queueing system serving lead-time sensitive customers with a single type of product. Incorporating non-exponential service times in an exact method for make-to-stock queues is usually deemed difficult. Our analysis of the proposed policies is exact and requires the numerical inversion of the Laplace transform of the sojourn time of an order to be placed. The first policy assures that the long-run probability of delivering the product within the quoted lead-time is the same for all backlogged customers. The second policy is a refinement of the first which improves the profitability if customers are oversensitive to even short delays in delivery. Numerical results show that both policies perform close to the optimal policy that was characterized only for exponential service times. The new insight gained is that the worsening impact of the production time variability, which is felt significantly in systems accepting all customers by quoting zero lead times, decreases when dynamic lead-time quotation policies are employed. 相似文献
6.
The authors presented the complications which occurred in patients after extracorporeal shock wave lithotripsy (ESWL), and discussed the methods of management of such patients. It was found that the most common complications were: renal colic, fever, "calculus route", and, less frequently, subcapsular and perirenal haematomas. In most patients conservative treatment was adequate. Some of these patients required admission to hospital and proper specialized management. 相似文献
7.
Sibel Duman Bülent Kaya Fatma Caf Barış Enez Sema Aguloğlu Fincan 《International Journal of Hydrogen Energy》2021,46(29):15410-15430
For the first time in this innovative study, microorganisms such as Bacillus simplex bacteria, mostly used in biological activity studies, are used as a bio-supporter agent of iron to release hydrogen from sodium borohydride hydrolysis at 25.0 ± 0.1 °C. The goal is to investigate thoroughly sodium borohydride hydrolysis catalyzed by Fe2O3 nanoparticles impregnated on microorganism such as Bacillus simplex (BS) bacteria (Fe2O3@BS NPs) known with strong antibacterial properties, which makes innovative them a candidate for hydrolysis reaction. This study was focused on the preparation, identification, and catalytic use of biocatalyst-like Fe2O3@BS NPs for hydrogen release from the sodium borohydride hydrolysis at 25.0 ± 0.1 °C. The characterization results made after and before hydrolysis reaction using by SEM/SEM-EDX, FT-IR, XRD, UV–vis, XPS, DLS, ELS Zeta potential, ESR, and TEM techniques reveal the formation of highly active, stable, durable, and long-lived biocatalysts-like Fe2O3@BS NPs. 相似文献
8.
Several current implementations of quantum circuits rely on the linear nearest neighbor restriction, which only allows interaction between adjacent qubits. Most methods that address the process of converting a generic circuit to an equivalent circuit which satisfies this restriction, minimize the number of additional SWAP gates required by this process. Moreover, most methods which address this problem are designed for 1D circuits. Considering the new and promising proposals for 2D quantum circuits, what we propose is a new perspective on this problem, namely that it can be seen as a multiobjective optimization problem. To test our hypothesis, we developed a multiobjective evolutionary algorithm that solves this problem by considering two objectives: minimizing the size of the 2D grid where the circuit is placed, and minimizing the number of additional SWAP gates. Of the methods designed for 2D circuits, only one considers different grid sizes which are much larger than strictly necessary. Consequently, our algorithm makes considerations which other methods do not make, since it naturally finds the grid which requires fewer SWAP gates for the circuit conversion, whether it is one-dimensional or two-dimensional. Our experimental results indicate that allowing a larger grid size results in fewer additional SWAP gates in about 73% of the tested circuits. Additionally, the average improvement we found when using larger grid sizes is about 30%, while the best improvement over using the smallest possible grid is 63.8%. 相似文献
9.
10.
Wirley Gonçalves Assunção Juliana Aparecida Delben Lucas Fernando Tabata Valentim Adelino Ricardo Barão Érica Alves Gomes 《Journal of Materials Engineering and Performance》2011,20(6):947-951
The passive fit between prosthesis and implant is a relevant factor for screw joint stability and treatment success. The aim
of this study was to evaluate the influence of vertical misfit in abutment-implant interface on preload maintenance of retention
screw of implant-supported crowns. The crowns were fabricated with different abutments and veneering materials and divided
into 5 groups (n = 12): Gold UCLA abutments cast in gold alloy veneered with ceramic (Group I) and resin (Group II), UCLA abutments cast in
titanium veneered with ceramic (Group III) and resin (Group IV), and zirconia abutments with ceramic veneering (Group V).
The crowns were attached to implants by gold retention screws with 35-N cm insertion torque. Specimens were submitted to mechanical
cycling up to 106 cycles. Measurements of detorque and vertical misfit in abutment-implant interface were performed before and after mechanical
cycling. ANOVA revealed statistically significant difference (P < 0.05) among groups for vertical misfit measured before and after mechanical cycling. The abutments cast in titanium exhibited
the highest misfit values. Pearson correlation test did not demonstrate significant correlation (P > 0.05) between vertical misfit and detorque value. It was concluded that vertical misfit did not influence torque maintenance
and the abutments cast in titanium exhibited the highest misfit values. 相似文献