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1.
William M. Pitts Martin Werrel Marco Fernandez Mary A. Long Evan A. Eisenberg James Filliben Cory D. Runyon 《火与材料》2021,45(1):127-154
Fire spread and growth on real‐scale four cushion mock‐ups of residential upholstered furniture (RUF) were investigated with the goal of identifying whether changes in five classes of materials (barrier, flexible polyurethane foam, polyester fiber wrap, upholstery fabric, and sewing thread), referred to as factors, resulted in statistically significant changes in burning behavior. A fractional factorial experimental design plus practical considerations yielded a test matrix with 20 material combinations. Experiments were repeated a minimum of two times. Measurements included fire spread rates derived from video recordings and heat release rates (HRRs). A total of 13 experimental parameters (3 based on the videos and 10 on the HRR results), referred to as responses, characterized the measurements. Statistical analyses based on Main Effects Plots (main effects) and Block Plots (main effects and factor interactions) were used. The results showed that three of the factors resulted in statistically significant effects on varying numbers of the 13 responses. The Barrier and Fabric factors had the strongest main effects with roughly comparable magnitudes. Foam was statistically significant for fewer of the responses and its overall strength was weaker than for Barrier and Fabric. No statistically significant main effects were identified for Wrap or Thread. Multiple two‐term interactions between factors were identified as being statistically significant. The Barrier*Fabric interaction resulted in the highest number of and strongest statistically significant effects. The existence of two‐term interactions means that it will be necessary to consider their effects in approaches designed to predict the burning behavior of RUF. 相似文献
2.
Dr. Ying Wang Prof. Dr. Andrew Ewing 《Chembiochem : a European journal of chemical biology》2021,22(5):807-813
Exocytosis plays an essential role in the communication between cells in the nervous system. Understanding the regulation of neurotransmitter release during exocytosis and the amount of neurotransmitter content that is stored in vesicles is of importance, as it provides fundamental insights to understand how the brain works and how neurons elicit a certain behavior. In this minireview, we summarize recent progress in amperometric measurements for monitoring exocytosis in single cells and electrochemical cytometry measurements of vesicular neurotransmitter content in individual vesicles. Important steps have increased our understanding of the different mechanisms of exocytosis. Increasing evidence is firmly establishing that partial release is the primary mechanism of release in multiple cell types. 相似文献
3.
Amphotericin B (AMB) was often used in intra-articular injection administration for fungal arthritis, because it could often bring a satisfactory therapeutic efficacy and a minimum systemic toxic side effect. However, because of the multiple operations and the frequent injections, the compliance of the patients was bad. Therefore, to develop a long-term sustained-released preparation of AMB for mycotic arthritis intra-articular administration is of great significance. The purpose of present study was to develop a long-term sustained-released in situ gel of a water-insoluble drug AMB for mycotic arthritis intra-articular administration. Based on the evaluations of the in vitro properties of the formulations, the formulation containing 10% (w/w) ethanol, 15% (w/w) PG, 0.75% (w/w) HA, 5% (w/w) purified soybean oil, 0.03% (w/w) α-tocopherol, 15% (w/w) water and 55% (w/w) glyceryl monooleate was selected as a suitable intra-articular injectable in situ gel drug delivery system for water-insoluble drug AMB. Furthermore, the results of the in vivo study on rabbits showed that the selected formulation was a safe and effective long-term sustained-released intra-articular injectable AMB preparation. Therefore, the presented in situ AMB gel could reduce the frequency of the administration in the AMB treatment of fungal arthritis, and then would get a good patient compliance. 相似文献
4.
目前管道泄漏检测方法可有效检测突发泄漏,对于缓慢泄漏则存在检测灵敏度低、定位不准确等问题。基于此,提出了一种基于信号增强的缓慢泄漏检测方法。通过信号压缩(抽取及移位)克服缓慢泄漏压力信号下降平缓的缺点;根据声波信号具有波形尖锐突出、对突发泄漏敏感的优点,通过建立以压力为输入、虚拟声波为输出的声波信号变送器模型,将压力信号转换为声波信号,克服了泄漏压力信号容易被淹没在管道压力波动及背景噪声中的缺点,实现了缓慢泄漏信号的增强;利用临近插值方法重构虚拟声波信号,基于延时互相关分析实现了缓慢泄漏的准确定位。实验结果表明,该方法具有显著的信号增强效果和定位精度,实现了缓慢泄漏的准确检测。 相似文献
5.
Valence M. K. Ndesendo Yahya E. Choonara Leith C. R. Meyer Pradeep Kumar Lomas K. Tomar Charu Tyagi 《Drug development and industrial pharmacy》2015,41(8):1274-1287
Context and objective: The aim of this study was to develop, characterize and evaluate a mucoadhesive caplet resulting from a polymeric blend (polymeric caplet) for intravaginal anti-HIV-1 delivery.Materials and methods: Poly(lactic-co-glycolic) acid, ethylcellulose, poly(vinylalcohol), polyacrylic acid and modified polyamide 6, 10 polymers were blended and compressed to a caplet-shaped device, with and without two model drugs 3′-azido-3′-deoxythymidine (AZT) and polystyrene sulfonate (PSS). Thermal analysis, infrared spectroscopy and microscopic analysis were carried out on the caplets employing temperature-modulated DSC (TMDSC), Fourier transform infra-red (FTIR) spectrometer and scanning electron microscope, respectively. In vitro and in vivo drug release analyses as well as the histopathological toxicity studies were carried out on the drug-loaded caplets. Furthermore, molecular mechanics (MM) simulations were carried out on the drug-loaded caplets to corroborate the experimental findings.Results and discussion: There was a big deviation between the Tg of the polymeric caplet from the Tg's of the constituent polymers indicating a strong interaction between constituent polymers. FTIR spectroscopy confirmed the presence of specific ionic and non-ionic interactions within the caplet. A controlled near zero-order drug release was obtained for AZT (20 d) and PSS (28 d). In vivo results, i.e. the drug concentration in plasma ranged between 0.012–0.332?mg/mL and 0.009–0.256?mg/mL for AZT and PSS over 1–28 d.Conclusion: The obtained results, which were corroborated by MM simulations, attested that the developed system has the potential for effective delivery of anti-HIV-agents. 相似文献
6.
Mingchang Lin Yufei Zhang Guosong Chen Ming Jiang 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(45):6065-6070
Glyco‐mimicking nanoparticles (glyco‐NPs) with Förster resonance energy transfer (FRET) donor and acceptor groups formed via dynamic covalent bond of benzoboroxole and sugar from two complementary polymers are prepared. The glyco‐NPs are proved to be quite stable under physiological conditions but sensitive to pH. So the glyco‐NPs can be internalized by dendritic cells with integrity and nontoxicity and then dissociate within the acidic organelles. This particle dissociation is directly observed and visualized in vitro, for the first time via the FRET measurements and fluorescent microscopy. This feature makes controlled release of drug or protein by glyco‐NPs possible, i.e., when model antigen Ovalbumin is loaded in the glyco‐NPs, the released Ovalbumin in dendritic cells stimulates T cells more efficiently than the free Ovalbumin itself as a result of the enhanced antigen processing and presentation. Thus, the results enlighten a bright future of the glyco‐NPs in immunotherapy. 相似文献
7.
Chitosan microspheres containing bromocresol green, cresol red, and phenolphthalein for corrosion detection, through pH change, are synthesized in order to be used in protective coatings for aluminium alloys. Microspheres containing corrosion detection species are characterized morphologically (SEM) and physico‐chemically (FTIR, TGA). Release studies (UV–vis) are performed in corrosion‐promoting conditions (pH, NaCl), and detection studies by immersion in media associated with corrosion activity while microspheres' sensing activity is evaluated visually. Electrochemical characterization of AA2024 substrates in the presence of chitosan spheres is performed to understand material performance, and a color change is observed as a result of local pH increase in cathodic areas when corrosion takes place. These findings can be correlated with the results from release studies and seem a promising approach for corrosion sensing purposes, not only because pH increase is possible to detect due to corrosion, but also because chitosan is considered an environmentally friendly material. 相似文献
8.
Application of chitosan–alginate microspheres for the sustained release of bacteriophage in simulated gastrointestinal conditions
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This study was designed to evaluate the acid stability, release property and antimicrobial efficacy of Escherichia coli O157:H7 bacteriophages encapsulated in chitosan–alginate microspheres under the simulated gastrointestinal conditions. The bacteriophages belonging to Myoviridae family were stable at the pH above 4 in trypticase soy broth. The chitosan–alginate microspheres exhibited protective effect on the viability of bacteriophages in the simulated gastric conditions at pH 2.0 and pH 2.5, showing 4.8 and 5.6 log PFU mL‐1, respectively, after 1 h of incubation at 37 °C. The release per cent of bacteriophages from microspheres gradually increased up to 65% in the simulated intestinal condition (pH 7.5) at 37 °C for 6 h. The lytic efficacy of chitosan‐ and alginate‐encapsulated bacteriophages against E. coli O157:H7 was significantly maintained in the simulated intestinal conditions to 10 h of incubation (1.3 log reduction). The results suggest that the chitosan–alginate microspheres can be used as a reliable delivery system for bacteriophages. 相似文献
9.
This work describes the functionalization of a natural and a man-made textile substrate, namely cotton and polyamide 6.6, with inclusion agents, β-cyclodextrins (β-CDs) that are able to release gradually to the user active ingredients. In this study we used aescin (aesculus hippocastanum extract), which is a natural agent with benefits for the treatment of varicose veins.1H NMR and UV–vis data supported the role of β-CDs as an aescin complexing agent, and the covalent nature of the linkage between β-cyclodextrins and the textile substrates, which showed a wash fastness to more than 45 washing cycles. 相似文献
10.
葛洲坝水利枢纽泄水建筑物进水口冲磨与修复 总被引:2,自引:1,他引:1
葛洲坝水利枢纽工程已运行20余年,近年水下检查中发现泄水建筑物进水口存在不同程度的冲磨,有些已威胁到建筑物安全运行,分析冲磨原因和探讨修复材料和手段是非常重要的,本文就此问题提出一些看法和建议供参考。 相似文献