- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Engineering organic electrochemical transistor (OECT) to be sensitive cell-based biosensor through tuning of channel area
摘要： The barrier integrity of epithelial tissue is crucial to many physiological functions in multicellular organisms. Hence, several scientific techniques, such as epithelial voltohmmeter (EVOM) and electric cell-substrate impedance sensing (ECIS), were developed to assess barrier function for in vitro assays. Organic electrochemical transistor (OECT), in particular, outperforms many biosensors because of its multiple advantages such as high transconductance, mixed ionic-electronic conductivity and high biocompatibility. Despite its extensive application in cell impedance sensing, little was reported on how its geometrical dimensions would affect the device performance and quality of cell-based measurement. In this work, OECTs in different dimensions were fabricated and characterized. Specifically investigated were their time and frequency responses towards the presence of epithelial cells (i.e. tightly packed colorectal adenocarcinoma cell line caco-2 and a novel leaky nasopharyngeal carcinoma cell line NPC43). Results show that the sensitivity of cell-based measurement is closely related to the impedance of the whole cell-OECT system. The performance of cell-based sensor would be affected by the tightness of target cell and can be tuned by controlling the active area of OECT.
关键词： Conducting polymer,Frequency response,Biosensor,Impedance spectroscopy,Transepithelial electrical resistance,Organic electrochemical transistor
更新于2025-09-23 15:23:52
-
Comparison between broadband and monochromatic photopic negative response in full-field electroretinogram in controls and subjects with primary open-angle glaucoma
摘要： Purpose A prospective, cross-sectional, case–control study was conducted to investigate the role of broadband and monochromatic photopic negative response (PhNR) of the full-field flash electroretinogram (ERG) in the evaluation of ganglion cell damage in primary open-angle glaucoma (POAG) subjects. Methods Subjects with POAG and age-matched normal subjects were recruited from the outpatient department of a tertiary eye care center in South India. A total of 25 patients with POAG and 50 age-matched normal subjects were recruited. ERG was recorded using broadband (3.5 cd.s/m2 white stimulus on 10 cd/m2 white background) and monochromatic (3.5 cd.s/m2 red stimulus on 10 cd/m2 blue background and 1 cd.s/m2 blue stimulus on 10 cd/m2 yellow background) stimuli. Results The reduction in PhNR amplitude in POAG compared to normal individuals was higher in red-on-blue PhNR [26.37 μV; p < 0.001, confidence interval (CI) 19.34 to 33.4] as compared to broadband stimuli (16.41 μV; p < 0.001, CI 8.68 to 24.13), and blue on yellow (21.96 μV; p < 0.001, CI 10.12 to 33.8). Red-on-blue PhNR amplitudes correlated better with mean deviation (MD; r = -0.66, p < 0.05), pattern standard deviation (PSD; r = -0.4, p = 0.04), visual field index (VFI; r = -0.58, p < 0.05), and retinal nerve fiber layer thickness (r = -0.67, p < 0.05) in comparison with broadband and monochromatic blue-on-yellow PhNR. Receiver operating characteristic curve revealed largest area under the curve (0.89) in red-on-blue PhNR compared to broadband (0.76) and blue on yellow (0.74). The sensitivity and specificity was also higher in red-on-blue PhNR (72% and 80%, respectively) as compared to the other stimuli (sensitivity and specificity of broadband 0.68 and 0.7, blue on yellow 0.64 and 0.7, respectively). Conclusion Correlation of PhNR with Humphrey visual field parameters and retinal nerve fiber layer thickness showed that red-on-blue PhNR can be a useful additional tool for clinical assessment of retinal ganglion cell dysfunction in glaucoma patients. Red-on-blue PhNR was more sensitive as compared to white-on-white and blue-on-yellow PhNR in identifying ganglion cell dysfunction and correlates well with other structural and functional tests for glaucoma such as MD, PSD, VFI, and RNFL thickness.
关键词： Primary open-angle glaucoma,Photopic negative response,Broadband ERG,Full-field electroretinogram,Monochromatic ERG
更新于2025-09-23 15:23:52
-
Enhancement strategies of targetability, response and photostability for in vivo bioimaging
摘要： Analyses of the physiology and pathology of active biochemical species in their native contexts are critical for early diagnosis and therapy. Optical imaging has emerged as one of the promising modalities for noninvasive and real-time visualization of important biomolecules or biological events, and it has witnessed major advances in the field of imaging in vitro and in vivo. In this review, we present a survey of common approaches and tactics for enhanced targetability, response rate, and photostability in bioimaging applications. Recently developed and representative examples are illustrated on the cellular and tissue levels.
关键词： targetability,bioimaging,photostability,response rate,fluorescent probe
更新于2025-09-23 15:23:52
-
Hydrophilic Poly(vinylidene Fluoride) Film with Enhanced Inner Channels for Both Water- and Ionic Liquid-Driven Ion-Exchange Polymer Metal Composite Actuators
摘要： This study presents a novel and facile strategy to fabricate a hydrophilic poly(vinylidene fluoride) (PVDF) electrolyte film with enhanced inner channels for a high-performance and cost-effective ion-exchange polymer metal composite (IPMC) actuator. The resultant PVDF composite film is composed of hierarchical micro/nanoscale structures: well-defined polymer grains with a diameter of ～20 μm and much finer particles with a diameter of ～390 nm, producing three-dimensional interconnected, hierarchical inner channels to facilitate ion migration of the electrolyte matrix film has a high porosity of 15.8% and yields a high water uptake of 44.2% and an ionic liquid (IL, [EMIm]·[BF4]) uptake of 38.1% to make both water-driven and IL-driven IPMC actuators because of the introduction of polar polyvinyl pyrrolidone. Compared to the conventional PVDF/IL-based IPMC, both water-driven and IL-driven PVDF-based IPMCs exhibit high ion migration rates, thus effectively improving the actuation frequency and producing remarkably higher levels of actuation force and displacement. Specifically, the force outputs are increased by 13.4 and 3.0 folds, and the displacement outputs are increased by 2.2 and 1.9 folds. Using an identical electrolyte matrix, water-driven IPMC exhibits stronger electromechanical performance, benefiting to make IPMC actuator with high levels of force and power outputs, whereas IL-driven IPMC exhibits a more stable electromechanical performance, benefiting to make long lifetime IPMC actuator in air. Thus, the resultant IPMCs are promising in the design of artificial muscles with tunable electromechanical performance for flexible actuators or displacement/vibration sensors at low cost.
关键词： ionic exchange polymer metal composite (IPMC),ionic liquid (IL),poly(vinylidene fluoride) (PVDF),inner channel,electromechanical response,polyvinyl pyrrolidone (PVP)
更新于2025-09-23 15:23:52
-
A dynamic model based on response factor method and seasonal performance analysis for integration of flat plate solar collector with building envelope
摘要： Integrating solar thermal collectors into building envelopes (e.g. walls or roofs) is very promising due to no need of additional site to place solar collectors. When a solar collector is integrated with a building, the working conditions for both the solar collector and the building envelope are changed. This paper proposed a new dynamic thermal model based on the response factor method. The new model combines the conventional analysis method for solar collectors with building envelopes, therefore it is easy to be understood and is more convenient to be realized by programming in a computer than state space model. The calculated results by the dynamic model agreed well with those calculated by the state space model and the measured experimental data, suggesting a satisfying validity of the model proposed. The seasonal performance of a solar wall (integrating of solar collectors and walls) in Beijing was studied by the new model. The results showed that: (1) In winter, the useful heat gain by the solar wall was always a little higher than the separate wall by about 6.7–8.8%, and the heat loss through solar wall is reduced by 90% or more, this is very favorable to reduce space heating load. (2) In summer, the useful heat gain of solar wall was higher than the separate collector by about 2.1–10.2%, the heat transferred through walls was less or higher than the separate wall depending on the inlet water temperature.
关键词： Dynamic model,Building heat transfer,Response factor method,Integration of solar collector with building,Useful heat gains
更新于2025-09-23 15:23:52
-
An Alternative Formulation for Optimum TMD Parameters Based on Equal Eigen Value Criteria
摘要： Closed form expressions for optimum Tuned Mass Damper (TMD) parameters are obtained by equating Eigen values of two modes and there is no need of any trial and error approach as used in earlier studies. For certain values of damping of main system and mass ratio, two sets of optimum parameters exist. For some other range of damping and mass ratio, modes become fully damped. In this range, optimum TMDs do not exist, and this happens for TMDs with large mass. The optimum TMD is shown to be quite robust and gives lesser TMD displacement as compared to optimum TMDs of earlier studies.
关键词： Equal modal frequency,Equal Eigen Value,Fully damped modes,Frequency response function,Optimum Tuned Mass Damper,Equal modal damping
更新于2025-09-23 15:23:52
-
Optical response of a bilayer crystal
摘要： We extend the recently developed classical theory for the optical response of a single-layer crystal to bilayers. We account for the interaction between the two atomic planes and the multiple reflections inside the crystals. We show how to define a global susceptibility meaningful for the bilayer crystal and how its expression varies compared to the single-layer case. We compute both the local and the macroscopic fields, which allow us to make a direct comparison with experimental data.
关键词： local fields,bilayer crystal,optical response,susceptibility,macroscopic fields
更新于2025-09-23 15:23:52
-
[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Performance Enhancement Of Cmos Terahertz Detector
摘要： For improving the performance of CMOS terahertz detectors, parasitic capacitance reduction technique and new working model are proposed for MOSFET devices. We investigate the influence of source parasitic capacitance and drain-to-source current on the performance of CMOS terahertz detectors and analyze the relationship to the voltage responsivity (RV) and noise equivalent power (NEP) of detectors. Experiment on the CMOS detectors with a 650GHz antenna shows the maximum improvement of voltage responsivity can attain to 155% by suppressing gate-source parasitic capacitance. The additional drain current Ids can further increase RV while NEP remains unchanged.
关键词： Antenna,CMOS THz detectors,DC current,Voltage response
更新于2025-09-23 15:23:52
-
[IEEE 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Paris, France (2018.10.14-2018.10.17)] 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Performance-Improved Maximum Power Point Tracking Control for PV System
摘要： Dc distribution systems are gaining attracted because of expanding the utilization of solar photovoltaic (PV) power. In such a situation, the design of the maximum power point tracking (MPPT) controllers should consider not only varying solar irradiance but also the dc bus voltage fluctuation. The purpose of this paper is to present a performance-improved MPPT controller using a derivative control to a PV panel voltage. The proposed method provides better performances than an existing reported method which uses the derivative control to a reactor current of a dc-dc converter. It is verified that the proposed method obtains quick responses to the rapid change of solar irradiance and dc bus voltage compared to conventional methods.
关键词： dc distribution system,dynamic response,PV system,maximum power point tracking (MPPT),dc-dc converter
更新于2025-09-23 15:23:52
-
Smart Lighting Systems as a Demand Response Solution for Future Smart Grids
摘要： Massive deployment of distributed and intermittent renewable energy sources cause instability in the power system because of the mismatch between the power generation and load consumption. In order to solve this problem, smart loads embedded with modern power electronic converters and communication devices are being developed. They are able to communicate with the utility and perform automatic demand response. In this paper, we propose a smart light-emitting diode (LED) driver for lighting. This smart LED driver adjusts its electricity usage in response to the utility without the expense of human visual comfort. To achieve this goal, a new control method is developed and a typical rate of change of LED power is determined through conducting a series of visual assessments with interviewees. An experimental smart LED driver is built to validate the new control method. Experimental report from the visual assessments has confirmed that the proposed control method can significantly reduce the light flickering caused by change of LED power.
关键词： Smart lighting,demand response,renewable energy,smart grid
更新于2025-09-23 15:23:52