Optical switching of nematic liquid crystal by means of photoresponsive polyimides as an alignment layer

Photosensitive polyimides (PIs) as an alignment layer induced optical switching of nematic liquid crystal (NLC) on photoirradiation at 366 nm. The orientation of NLC molecule was changed from homogeneous to homeotropic alignment on photoirradiation with a dc electric field as a bias. The optical switching behavior of NLC was largely affected by the chemical structures of PIs. (C) 1999 American Institute of Physics. [S0003-6951(99)02748-5]open91

Transparent and UV-Reflective Photonic Films and Supraballs Composed of Hollow Silica Nanospheres

For an optically transparent, UV-reflective film, hollow silica nanospheres smaller than the visible wavelength (<lambda(vis)) are prepared and assembled into colloidal glasses, of which interstices are then backfilled with a polymer. The polymer refractive index is matched with the silica shell to minimize backscattering in the visible range, and the average distance between the hollow silica particles is adjusted by tuning the shell thickness to satisfy the interference resonance condition for a UV selective reflection. The resulting composite film shows a strong UV reflection as expected, but it is translucent in visible light due to non-negligible backscattering, which may be caused by large defects or fluctuation of the particle concentration. In order to avoid such backscattering, another polymer is introduced of which the refractive index is matched with the average refractive index of the hollow nanospheres. This allows an optically transparent film that selectively reflects the UV light. Furthermore, spherical aggregates of hollow silica nanospheres called "supraballs" are prepared and their average refractive index is matched with a solvent by adjusting the mixture ratio of water and ethylene glycol, which yields an optically transparent solution, selectively reflecting UV

AP-1/IRF-3 Targeted Anti-Inflammatory Activity of Andrographolide Isolated from Andrographis paniculata

Andrographolide (AG) is an abundant component of plants of the genus Andrographis and has a number of beneficial properties including neuroprotective, anticancer, anti-inflammatory, and antidiabetic effects. Despite numerous pharmacological studies, the precise mechanism of AG is still ambiguous. Thus, in the present study, we investigated the molecular mechanisms of AG and its target proteins as they pertain to anti-inflammatory responses. AG suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2), as well as the mRNA abundance of inducible NO synthase (iNOS), tumor necrosis factor-alpha (TNF-α), cyclooxygenase (COX)-2, and interferon-beta (IFN-β) in a dose-dependent manner in both lipopolysaccharide- (LPS-) activated RAW264.7 cells and peritoneal macrophages. AG also substantially ameliorated the symptoms of LPS-induced hepatitis and EtOH/HCl-induced gastritis in mice. Based on the results of luciferase reporter gene assays, kinase assays, and measurement of nuclear levels of transcription factors, the anti-inflammatory effects of AG were found to be clearly mediated by inhibition of both (1) extracellular signal-regulated kinase (ERK)/activator protein (AP)-1 and (2) IκB kinase ε (IKKε)/interferon regulatory factor (IRF)-3 pathways. In conclusion, we detected a novel molecular signaling pathway by which AG can suppress inflammatory responses. Thus, AG is a promising anti-inflammatory drug with two pharmacological targets

Anti-Allergic Activity of a Platycodon Root Ethanol Extract

Platycodon grandiflorum (Campanulaceae) is used as traditional medicine in Asian countries. In Korean traditional medicine, Platycodon root has been widely used since ancient times as a traditional drug to treat cold, cough and asthma. However, its effects on bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanisms remain unknown. In this study, the biological effect of Platycodon root ethanol extract (PE) was evaluated in BMMC after induction of allergic mediators by phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187) stimulation. The effect of PE on the production of several allergic mediators, such as interleukin-6 (IL-6), prostaglandin D2 (PGD2), leukotriene C4 (LTC4), β-Hexosaminidase (β-Hex) and cyclooxygenase-2 (COX-2) protein, was investigated. The results demonstrate that PE inhibits PMA + A23187 induced production of IL-6, PGD2, LTC4, β-Hexosaminidase and COX-2 protein. Taken together, these results indicate that PE has the potential for use in the treatment of allergy

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Battery Thermal Management Design Modeling

Battery thermal management is critical in achieving performance and the extended life of batteries in electric and hybrid vehicles under real-driving conditions. Appropriate modeling for predicting thermal behavior of battery systems in vehicles helps to make decisions for improved design and shortens the development process. For this paper, we looked at the impact of cooling strategies with air and direct/indirect liquid cooling. The simplicity of an air-cooling system is an advantage over a liquid-cooling system. In addition to its intrinsically lower heat transfer coefficient, another disadvantage of air cooling is that the small heat capacity of air makes it difficult to accomplish temperature uniformity inside a cell or between cells in a module. Liquid-cooling is more effective in heat transfer and takes up less volume, but the added complexity and cost may outweigh the merits. The surface heat transfer coefficient, h, and the blower power for air cooling are sensitive to the hydraulic diameter of the cooling channel (Dh). However, because of the added thermal resistances, h evaluated at cell surface is not as sensitive to the variation of Dh in an indirect (water/glycol jacket) cooling system. Due to the high heat transfer coefficient at small Dh, direct liquid cooling using dielectric mineral oils may be preferred in spite of high pressure loss in certain circumstances such as in highly transient large heat generating battery systems. In general, air-cooling should be considered first, as the power demand increases with heavier vehicles and more aggressive driving, water/glycol jacket cooling should be considered next. Results of computational fluid dynamics model simulation imply that capturing the internal heat flow paths and thermal resistances inside a cell using a sophisticated three-dimensional cell model is important for more accurate prediction of cell/battery thermal behaviors. This paper identified analyses and approaches that engineers should consider when they design a battery thermal management system for vehicles

Thermal Management of Batteries in Advanced Vehicles Using Phase-Change Materials

Hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs) are promising technologies to help reduce the amount of petroleum consumed for transportation. In both HEVs and PHEVs, the battery pack is a key component to enabling their fuel savings potential. The battery is also one of the most expensive components in the vehicle. One of the most significant factors impacting both the performance and life of a battery is temperature. In particular, operating a battery at elevated temperatures reduces its life. It is therefore important to design and implement effective battery thermal management systems. This paper analyzes the suitability of phase-change material (PCM) for battery thermal management in HEV and PHEV systems. A prototype PCM/graphite matrix module (that was not fully optimized for HEV applications) was evaluated experimentally under geometric and vehicle-simulation-based drive cycles. The results were used to validate a thermal model. The model was then used to explore the benefits and limitations of PCM thermal management. This study suggests that PCM can provide a peak-temperature-limiting benefit in vehicle applications, but the overall battery thermal management solution must rely on active cooling or on limiting the battery’s power output (or both) to avoid high temperatures during continuous cycling. Ultimately, vehicle designers will need to weigh the potential increase in mass and cost associated with adding PCM to the thermal management system against the anticipated benefits: a smaller active cooling system, less need to limit battery power output in high-temperature conditions, and/or potentially reduced exposure to momentary or localized high cell temperatures