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101.
Friederike Freiin von Hvel Ekaterini Kefalakes Claudia Grothe 《International journal of molecular sciences》2021,22(1)
Fibroblast growth factor 2 (FGF-2), ubiquitously expressed in humans and mice, is functionally involved in cell growth, migration and maturation in vitro and in vivo. Based on the same mRNA, an 18-kilo Dalton (kDa) FGF-2 isoform named FGF-2 low molecular weight (FGF-2LMW) isoform is translated in humans and rodents. Additionally, two larger isoforms weighing 21 and 22 kDa also exist, summarized as the FGF-2 high molecular weight (FGF-2HMW) isoform. Meanwhile, the human FGF-2HMW comprises a 22, 23, 24 and 34 kDa protein. Independent studies verified a specific intracellular localization, mode of action and tissue-specific spatiotemporal expression of the FGF-2 isoforms, increasing the complexity of their physiological and pathophysiological roles. In order to analyze their spectrum of effects, FGF-2LMW knock out (ko) and FGF-2HMWko mice have been generated, as well as mice specifically overexpressing either FGF-2LMW or FGF-2HMW. So far, the development and functionality of the cardiovascular system, bone formation and regeneration as well as their impact on the central nervous system including disease models of neurodegeneration, have been examined. This review provides a summary of the studies characterizing the in vivo effects modulated by the FGF-2 isoforms and, thus, offers a comprehensive overview of its actions in the aforementioned organ systems. 相似文献
102.
This article proposes an active balancer, which features bidirectional charge shuttling and adaptive equalization current control, to fast counterbalance the state of charge (SOC) of cells in a lithium-ion battery (LIB) string. The power circuit consists of certain bidirectional buck-boost converters to transfer energy among the different cells back and forth. Owing to the characterization of the open-circuit voltage (OCV) vs SOC in LIB being relatively smooth near the SOC middle range, the SOC-inspected balance strategy can achieve more precise and efficient equilibrium than the voltage-based control. Accordingly, a compensated OCV-based SOC estimation is put forward to take into account the discrepancy of SOC estimation. Besides, the varied-duty-cycle (VDC) and curve-fitting modulation (CFM) methods are devised herein to tackle the problems of slow equalization rate and low balance efficacy, which arise from the diminution in balancing current as the SOC difference between the cells decreases in the later duration of equalization especially. The proposed strategies have taken the battery nonlinear characteristic and circuit parameter nonideality into account and can adaptively modulate the duty cycle with the SOC difference to keep balancing current constant throughout the balancing cycle. Simulated and experimental results are given to demonstrate the feasibility and effectiveness of the same prototype constructed. Compared with the fixed duty cycle and the VDC methods, the proposed CFM has the best balancing efficiency of 81.4%, and the balance time is shortened by 27.1% and 18.6%, respectively. 相似文献
103.
104.
海胆酮是一种酮式类胡萝卜素,主要从海胆及藻类等海洋生物中提取。本文研究海胆酮对乙酰胆碱酯酶(acetylcholinesterase,AChE)的抑制作用,应用酶动力学、荧光光谱、圆二色光谱和分子对接技术研究海胆酮对AChE的抑制机理,并用淀粉样β蛋白片段25~35(amyloid beta-peptide 25-35,Aβ25-35)诱导大鼠肾上腺嗜铬细胞瘤细胞(PC12细胞)建立阿尔茨海默症(Alzheimer’s disease,AD)模型,研究海胆酮对AD细胞模型氧化应激损伤的作用。结果表明,海胆酮有很强的AChE抑制活性,其半抑制质量浓度为(16.29±0.97)μg/mL,抑制常数Ki为3.82 μg/mL,表现为竞争性抑制;海胆酮可诱导AChE二级结构改变,更容易与AChE活性中心氨基酸Ser200、His440、Trp84和Tyr121结合,阻碍底物碘代硫代乙酰胆碱(acetylthiocholine iodide,ATCI)与酶结合,从而引起酶活力降低。海胆酮能有效抑制Aβ25-35诱导PC12细胞的AChE活力,降低丙二醛含量,增加超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活力,减轻Aβ25-35诱导的PC12细胞氧化应激损伤。本研究基于AChE和氧化应激阐明了海胆酮对AD的潜在作用机制,为海胆酮在功能食品、生物医药等领域的应用提供了数据支持和理论根据。 相似文献
105.
With the increase of industrialization and urbanization, humankind faces massive oil-based pollution due to tanker accidents, human error, and natural disasters. For this, hydrophobic sorbents are fabricated and their applications for the removal of oil from polluted water sources are investigated. These hydrophobic sorbents are prepared by the condensation reaction of poly(dimethylsiloxane) and tris[3-(trimethoxysilyl)propyl]isocyanurate cross-linker via bulk polymerization. The obtained sorbents exhibit high oil sorption capacity, fast absorption–desorption kinetics, and great reusability. Moreover, they can selectively absorb oil from the water surface, thus making them practical for water clean-up applications. 相似文献
106.
The Fe/C/SiCN composite ceramics were synthesized by polymer-derived method to obtain the integration of structure and functions. The electromagnetic waves (EMW) absorption properties at X and Ku bands were investigated. The addition of nano-sized Fe particles improved the magnetic loss and impedance matching, and the carbon nanotubes generated by the iron in-situ catalysis increased the internal relaxation polarization and interfacial polarization, which together improved the EMW absorption properties significantly. In particular, the Fe/C/SiCN-9 showed the optimum reflection loss (RL) of ?31.06 dB at 10.03 GHz with an effective absorption bandwidth (EAB, RL < ?10 dB) of 3.03 GHz at 2.51 mm, indicating the excellent EMW absorption properties of Fe/C/SiCN composite ceramics. 相似文献
107.
The bacterial formulations, spinosad and spinetoram, were evaluated for their efficacy in suppressing development and mating success in Cadra cautella (Walk.) (Lepidoptera: Pyralidae), the almond moth. A dilution series of spinosad and spinetoram was sprayed on rice flour. Rice flour samples sprayed with water served as the control. Late instar C. cautella larvae were introduced onto spinosad-, spinetoram-, or water-treated rice flour. The first experiment tested the effects of spinosad and spinetoram on larval mortality, as well as emergence of adults and progeny at different insecticide concentrations. In the second experiment, the mating success of C. cautella adults that had emerged from larvae exposed to spinosad was tested inside a cubicle. Both spinosad and spinetoram increased larval mortality, whereas both compounds reduced adult emergence and progeny production. Natural mating was reduced in the presence of the synthetic sex pheromone (Z,E)-9,12-tetradecadienyl acetate. However, exposure of C. cautella larvae to spinosad did not alter mating in adult progeny. Spinosad was more effective than spinetoram at suppressing C. cautella development. The study concludes that both spinosad and spinetoram suppress the development of immatures of C. cautella to the adult stage as well as mating. Thus, the both compounds can be used to protect stored grains from infestation by C. cautella. 相似文献
108.
109.
Material encapsulation is a relatively new technique for coating a micro/nanosize particle or droplet with polymeric or inorganic shell. Encapsulation technology has many applications in various fields including drug delivery, cosmetic, agriculture, thermal energy storage, textile, and self-healing polymers. Poly(methyl methacrylate) (PMMA) is widely used as shell material in encapsulation due to its high chemical stability, biocompatibility, nontoxicity, and good mechanical properties. The main approach for micro/nanoencapsulation of materials using PMMA as shell comprises emulsion-based techniques such as emulsion polymerization and solvent evaporation from oil-in-water emulsion. In the present review, we first focus on the encapsulation techniques of liquid materials with PMMA shell by analyzing the effective processing parameters influencing the preparation of PMMA micro/nanocapsules. We then describe the morphology of PMMA capsules in emulsion systems according to thermodynamic relations. The techniques to investigation of mechanical properties of capsule shell and the release mechanisms of core material from PMMA capsules were also investigated. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48039. 相似文献
110.
华治国 《混凝土与水泥制品》2020,(6):70-72
选择了几份典型的外墙外保温系统标准,通过对这几份标准中胶粘剂和抹面胶浆的成型和检测方法的比较,分析了现有检测技术的优劣,并结合工作实践提出了建议。 相似文献