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101.
The toxicity of polyaniline (PANI) nanomaterials with four different aspect ratios on human lung fibroblast cells was investigated by cell viability assay, cytotoxicity assay, apoptosis/necrosis measurement, and reactive oxygen species production. The toxicity increased with decreasing aspect ratio of PANI nanomaterials. In contrast, the highest aspect ratio PANI nanomaterials showed similar results with bulk PANI materials. The adverse effect of PANI nanomaterials was also concentration- and time-dependent. Low aspect ratio PANI nanomaterials induced more necrosis and more reactive oxygen species than others. These results provide new understanding of shape-dependent toxicity of nanomaterials. 相似文献
102.
103.
Dong-Yong Hong Dong-Hun Lee Ji-Young Lee Eun-Chae Lee Sang-Won Park Man-Ryul Lee Jae-Sang Oh 《International journal of molecular sciences》2022,23(15)
The low-density-lipoprotein receptor (LDLr) removes low-density lipoprotein (LDL), an endovascular transporter that carries cholesterol from the bloodstream to peripheral tissues. The maintenance of cholesterol content in the brain, which is important to protect brain function, is affected by LDLr. LDLr co-localizes with the insulin receptor and complements the internalization of LDL. In LDLr deficiency, LDL blood levels and insulin resistance increase, leading to abnormal cholesterol control and cognitive deficits in atherosclerosis. Defects in brain cholesterol metabolism lead to neuroinflammation and blood–brain-barrier (BBB) degradation. Moreover, interactions between endoplasmic reticulum stress (ER stress) and mitochondria are induced by ox-LDL accumulation, apolipoprotein E (ApoE) regulates the levels of amyloid beta (Aβ) in the brain, and hypoxia is induced by apoptosis induced by the LDLr defect. This review summarizes the association between neurodegenerative brain disease and typical cognitive deficits. 相似文献
104.
A low-cost broadband millimetre-wave planar 30/spl times/30 array antenna is presented. The antenna is fed by a microstrip feed network in the H-plane to decrease fabrication costs, and a waveguide feed network in the E-plane to reduce the feed line loss. The waveguide and microstrip feed network are coupled through the proposed slot pair. The slots are placed one quarter of a guided-wavelength distance apart, so that the reflected waves from the slots cancel each other. A conductive bar is laid above the slots to increase the coupling, which increases the antenna gain by about 1 dBi. The maximum gain is 30.5 dBi at 41.5 GHz. The measured bandwidth is as broad as 7.1%. 相似文献
105.
Chip-on-glass (COG) interconnection using anisotropic conductive film (ACF) is susceptible to open failures. Open failures
can be induced by the absence of conductive particles or an insufficient contact. Experimental results as well as statistical
approaches were used to understand the conditions for open failures in COG bonding. The binomial distribution was used to
predict the probability of the open failure due to the deficiency of conductive particles. The probability of an open failure
decreased with increasing bump area and decreasing particle size. The bump height variation was also an important factor that
affected the probability of the open failure together with the bump-to-electrode gap and the particle size. The variation
in bump height should be minimized to avoid open failures in fine-pitch applications where a smaller particle size is required. 相似文献
106.
Min-Cheol Oh Myung-Hyun Lee Hyung-Jong Lee 《Photonics Technology Letters, IEEE》1999,11(9):1144-1146
A waveguide polarization splitter is demonstrated based on a low-loss polymer waveguide and a birefringent polyimide. Crosslinkable fluorinated polymers with an excellent stability and a low absorption loss are utilized for the device. The polyimide is buried under one branch of the Y-branch waveguide to enhance the birefringence between the TE and TM modes. By the adiabatic mode evolution, the TE mode is coupled to the branch with the polyimide strip, while the TM mode propagates through the other branch without the polyimide. For the device with a branch angle of 1/400 rad, we obtained a crosstalk less than -20 dB and a fiber-to-fiber insertion loss of 3.8 dB 相似文献
107.
Yosuke Inomata Jae-Won Oh Kohei Taniguchi Nobuhiko Sugito Nao Kawaguchi Fumitoshi Hirokawa Sang-Woong Lee Yukihiro Akao Shinji Takai Kwang-Pyo Kim Kazuhisa Uchiyama 《International journal of molecular sciences》2022,23(9)
Non-alcoholic steatohepatitis (NASH) has pathological characteristics similar to those of alcoholic hepatitis, despite the absence of a drinking history. The greatest threat associated with NASH is its progression to cirrhosis and hepatocellular carcinoma. The pathophysiology of NASH is not fully understood to date. In this study, we investigated the pathophysiology of NASH from the perspective of glycolysis and the Warburg effect, with a particular focus on microRNA regulation in liver-specific macrophages, also known as Kupffer cells. We established NASH rat and mouse models and evaluated various parameters including the liver-to-body weight ratio, blood indexes, and histopathology. A quantitative phosphoproteomic analysis of the NASH rat model livers revealed the activation of glycolysis. Western blotting and immunohistochemistry results indicated that the expression of pyruvate kinase muscle 2 (PKM2), a rate-limiting enzyme of glycolysis, was upregulated in the liver tissues of both NASH models. Moreover, increases in PKM2 and p-PKM2 were observed in the early phase of NASH. These observations were partially induced by the downregulation of microRNA122-5p (miR-122-5p) and occurred particularly in the Kupffer cells. Our results suggest that the activation of glycolysis in Kupffer cells during NASH was partially induced by the upregulation of PKM2 via miR-122-5p suppression. 相似文献
108.
Jun-Shin Lee Bong-Ki Kim Wook-Ryun Lee Ki-Yong Oh 《Journal of Mechanical Science and Technology》2010,24(10):1975-1980
Understanding water hammer is very important to the prevention of excessive pressure build-up in pipelines. Many researchers
have studied this phenomenon, drawing effective solutions through the time- and frequency-domain approaches. For the purposes
of enhancing the advantages of the frequency-domain approach and, thereby, rendering investigations of the dynamic characteristics
of pipelines more effective, we propose partial fraction expansion of the transfer function between the unsteady flow source
and a given section. We simulate the proposed approach using a vibration element inserted into a simple pipeline, deducing
much useful physical information pertaining to pipeline design. We conclude that locating the resonance of the vibration element
between the first and second resonances of the pipeline can mitigate the excessive pressure build-up attendant on the occurrence
of water hammer. Our method of partial fraction expansion is expected to be useful and effective in analyses of unsteady flows
in pipelines. 相似文献
109.
Kyung Hwan Oh Seong Min Kim Mi Jung Lee Jin Kyoon Park 《Advanced Synthesis \u0026amp; Catalysis》2015,357(18):3927-3935
A direct method for the arylation of 1,2‐azolo[1,5‐a]pyridines has been developed. In the process, the fused pyridines react with aryl halides in the presence of the palladium complex Pd(OAc)2(Phen) as a catalyst and copper(I) chloride (CuCl) as a Lewis acid to form arylated derivatives. While pyrazolo[1,5‐a]pyridines and [1,2,4]triazolo[1,5‐a]pyridines are arylated at ortho‐positions of their pyridine rings using this method, in situ ring‐opening of the formed C‐7 arylated [1,5‐a]pyridine takes place to generate the 2,6‐disubstituted pyridine. Also, upon treatment with lithium diisopropylamide (LDA), C‐7 arylated pyrazolo[1,5‐a]pyridine‐3‐carboxylates react to produce diversely substituted 2,6‐disubstituted pyridines. Finally, a sequential C‐3 arylation was accomplished through a two‐step sequence involving hydrolysis of pyrazolo[1,5‐a]pyridine‐3‐carboxylates followed by the bimetallic Pd/Cu‐catalyzed decarboxylative coupling reaction with aryl bromide.
110.
Modeling of a membrane reactor system for crude palm oil transesterification. Part II: Transport phenomena 下载免费PDF全文
Pin Pin Oh Mei Fong Chong Harrison Lik Nang Lau Yuen May Choo Junghui Chen 《American Institute of Chemical Engineers》2015,61(6):1981-1996
The mechanistic modeling of biodiesel production process in membrane reactor with the consideration of chemical reaction, phase equilibrium, and ultrafiltration is important for the membrane reactor design. In part II of this work, the chemical and phase equilibrium (CPE) model for crude palm oil transesterification reaction in the membrane reactor developed in part I is extended to an integration of CPE with modified Maxwell–Stefan model, which considers multicomponent mass transport phenomena of concentration polarization and intramembrane. A good fit of simulated permeate fluxes and apparent solute rejection to the experimental data shows that the model has a good prediction capability. Reversible fouling was found to be the major fouling and no pore plugging was observed. Simulation results verified that micelles were retained by the membrane at CPO:MEOH molar ratio of 1:24 and catalyst concentration of 0.5 wt %. However, phase inversion happened when catalyst concentration of 0.05 and 0.1 wt % were used. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1981–1996, 2015 相似文献