Kidney organoids derived from the human pluripotent stem cells (hPSCs) recapitulating human kidney are the attractive tool for kidney regeneration, disease modeling, and drug screening. However, the ...kidney organoids cultured by static conditions have the limited vascular networks and immature nephron-like structures unlike human kidney. Here, we developed a kidney organoid-on-a-chip system providing fluidic flow mimicking shear stress with optimized extracellular matrix (ECM) conditions. We demonstrated that the kidney organoids cultured in our microfluidic system showed more matured podocytes and vascular structures as compared to the static culture condition. Additionally, the kidney organoids cultured in microfluidic systems showed higher sensitivity to nephrotoxic drugs as compared with those cultured in static conditions. We also demonstrated that the physiological flow played an important role in maintaining a number of physiological functions of kidney organoids. Therefore, our kidney organoid-on-a-chip system could provide an organoid culture platform for in vitro vascularization in formation of functional three-dimensional (3D) tissues.
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Developing efficient and stable hydrogen gas sensors may be of urgent demand for its safety uses. Herein, Pd@N-CeO2 core–shell nanoflatforms (CSNFs) are fabricated and utilized for ...this purpose. The resulting Pd@N-CeO2 CSNFs offer small particle sizes with high Brunauer–Emmett–Teller (BET) surface area and porous nanostructures. The core–shell sensors establish high hydrogen sensing response and fast response and recovery times at a lower optimal working temperature compared to undoped and doped CeO2 ones. In addition, it further demonstrates high selectivity and stability toward hydrogen gas among interfering different target gases. The hydrogen gas sensing betterment is synergistically assigned to Pd core, N dopant, and high BET surface area effects, which decidedly modulate the electrical resistance of core–shell sensors to improve overall gas sensing performance accordingly. Our finding provides an efficient way to design and fabricate versatile hydrogen gas sensors based on metal@nitrogen doped-semiconductor oxide core–shell nanostructures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A three-dimensional (3D) tumor spheroid model plays a critical role in mimicking tumor microenvironments in vivo. However, the conventional culture methods lack the ability to manipulate the 3D tumor ...spheroids in a homogeneous manner. To address this limitation, we developed a microfluidic-based droplet system for drug screening applications. We used a tree-shaped gradient generator to control the cell density and encapsulate the cells within uniform-sized droplets to generate a 3D gradient-sized tumor spheroid. Using this microfluidic-based droplet system, we demonstrated the high-throughput generation of uniform 3D tumor spheroids containing various cellular ratios for the analysis of the anti-cancer drug cytotoxicity. Consequently, this microfluidic-based gradient droplet generator could be a potentially powerful tool for anti-cancer drug screening applications.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In the present study, we assessed the effect of the ethanolic extract of the seeds of Cassia obtusifolia (COE) on the learning and memory impairments induced by scopolamine or transient bilateral ...common carotid artery occlusion (2VO). In a study of the cholinergic dysfunction induced by scopolamine, single COE (25, 50, or 100 mg/kg, p.o.) administration significantly attenuated scopolamine-induced cognitive impairments as determined by the passive avoidance and Y-maze tasks (P<0.05) and also reduced escape-latency on the Morris water maze task (P<0.05). In the 2VO study, COE (50 mg/kg, p.o.) significantly reversed 2VO-induced cognitive impairments in mice by the passive avoidance and the Y-maze tasks (P<0.05). Moreover, COE (50 mg/kg, p.o.) also reduced escape-latency and prolonged swimming time in the target quadrant during a probe trial of the Morris water maze task (P<0.05). In an in vitro study, COE was found to inhibit acetylcholinesterase activity in a dose-dependent manner (IC50 value: 81.6 µg/ml). Furthermore, COE also inhibited acetylcholinesterase activity in an ex vivo study. These results suggest that COE attenuates memory impairment induced by scopolamine or 2VO and that these effects are mediated by enhancing the cholinergic nervous system via acetylcholinesterase inhibition.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We reported on the ablation depth control with a resolution of 40nm on indium tin oxide (ITO) thin film using a square beam shaped femtosecond (190fs) laser (λp=1030nm). A slit is used to make the ...square, flat top beam shaped from the Gaussian spatial profile of the femtosecond laser. An ablation depth of 40nm was obtained using the single pulse irradiation at a peak intensity of 2.8TW/cm2. The morphologies of the ablated area were characterized using an optical microscope, atomic force microscope (AFM), and energy dispersive X-ray spectroscopy (EDS). Ablations with square and rectangular types with various sizes were demonstrated on ITO thin film using slits with varying x–y axes. The stereo structure of the ablation with the depth resolution of approximately 40nm was also fabricated successfully using the irradiation of single pulses with different shaped sizes of femtosecond laser.
•ITO thin film was patterned using a femtosecond laser direct patterning technique.•The square shaped laser beam with flat-top energy distribution was carried out using a slit module.•The square shaped laser beam with pulse number control technique was applied for ablation depth control.•The ablation depth control with a resolution of 40nm on ITO thin films was investigated using a square beam-shaped femtosecond laser.•Ablations with square and rectangular types with various sizes were demonstrated on ITO thin film.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We demonstrate a novel approach to improve laser machining quality on metals by vibrating the optical objective lens with a frequency (of 500Hz) and various displacements (0–16.5μm) during a ...femtosecond laser machining process. The laser used in this experiment is an amplified Ti:sapphire fs laser system that generates 100fs pulses having an energy of 3.5mJ/pulse with a 5kHz repetition rate at a central wavelength of 790nm. It is found that both the wall surface finish of the machined structures and the aspect ratio obtained using the frequency vibration assisted laser machining are improved, compared to those derived via laser machining without vibration assistance. This is the first report of low frequency vibration of an optical objective lens in the femtosecond laser machining process being exploited to obtain significantly improved surface roughness of machined side walls and increased aspect ratios.
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► The experimental setup of vibration-assisted femtosecond laser machining system. ► The wall surface finish of the machined structures using the vibration assisted laser machining is improved. ► Compared to laser machining without vibration assistance. ► Aspect ratio got using rate vibration assist laser machining are better, compare to laser machining without vibration assist.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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► The experimental setup for the removal of nanoparticles using plasma shockwaves formed by a femtosecond pulsed laser. ► Removal of PSL nanoparticles from the silicon wafer surface ...as a function of the gap distance and particle counting. ► The removal efficiency of the nanoparticles reached 95% without surface damage when the gap distance was 150μm.
Experiments on the cleaning effect of 100nm-sized polystyrene latex (PSL) particles on silicon wafers using plasma shockwaves excited via a femtosecond (130fs) Ti:Sapphire laser (λp=790nm) are reported. By the scan of wafer using the X–Y–Z stage during excited plasma shockwave, the removal variation of nanoparticles on surface was observed in situ before and after plasma shockwave occurred. The cleaning efficiency was strongly dependent on the gap distance between the plasma formation point and the surface. The removal efficiency of the nanoparticles reached 95% without surface damage when the gap distance was 150μm.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Humidity dependence of gas sensing characteristics in oxide chemiresistors is the greatest obstacle for gas sensor applications. On page 4229 J.‐H. Lee and co‐workers suggest a strategy to design ...humidity independent gas sensors by dynamic and regenerative self‐refreshing of an indium oxide sensor surface assisted by layer‐by‐layer coated cerium oxide nanoclusters.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We report that inverted iron oxide nanoparticles (i-IONPs) have great potential for musculoskeletal imaging, which is one of the fastest-growing fields in MRI. Upon intra-articular injection, i-IONPs ...provide positive T 1 values and decent soft tissue contrast effects, allowing a clear visualization of complex anatomical details of the joint. i-IONPs show substantially stronger and longer-lasting T 1 contrast effects than clinical gadolinium-based contrast agents. In addition, i-IONPs are completely eliminated from the joint cavity without accumulation or harmful effects and are excreted from body through a renal clearance route.
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IJS, KILJ, NUK, PNG, UL, UM
Selective patterning of carbon nanotubes film on transparent substrates was performed using a femtosecond laser. The high shock wave generated by the femtosecond laser effectively removed the carbon ...nanotubes without damage to the substrate. This process has many advantages because it is performed without chemicals and is easily applied to large-area patterning. It could also control the transparency and conductivity of carbon nanotubes film by selective removal of carbon nanotubes. Furthermore, a femtosecond laser does not cause any phase change in the CNTs, as usually occurs in focused ion beam irradiation of carbon nanotubes. The patterned single-walled carbon nanotube films on transparent substrate can be used as an electrode layer for touch panels of flexible or flat panel displays instead of indium tin oxide film.
•Fabrication of topological architectures on carbon nanotube-based coatings.•Patterning of single-walled carbon nanotubes film to femtosecond laser pulses.•Femtosecond laser-induced nanotubes alignment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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