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Using prerecorded hemodynamic response functions in detecting prefrontal pain response: a functional near-infrared spectroscopy study
摘要： Currently, there is no method for providing a nonverbal objective assessment of pain. Recent work using functional near-infrared spectroscopy (fNIRS) has revealed its potential for objective measures. We conducted two fNIRS scans separated by 30 min and measured the hemodynamic response to the electrical noxious and innocuous stimuli over the anterior prefrontal cortex (aPFC) in 14 subjects. Based on the estimated hemodynamic response functions (HRFs), we first evaluated the test–retest reliability of using fNIRS in measuring the pain response over the aPFC. We then proposed a general linear model (GLM)-based detection model that employs the subject-specific HRFs from the first scan to detect the pain response in the second scan. Our results indicate that fNIRS has a reasonable reliability in detecting the hemodynamic changes associated with noxious events, especially in the medial portion of the aPFC. Compared with a standard HRF with a fixed shape, including the subject-specific HRFs in the GLM allows for a significant improvement in the detection sensitivity of aPFC pain response. This study supports the potential application of individualized analysis in using fNIRS and provides a robust model to perform objective determination of pain perception.
关键词： test–retest reliability,detection sensitivity,hemodynamic response function,anterior prefrontal cortex,pain,near-infrared spectroscopy
更新于2025-09-10 09:29:36
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A dual-responsive fluorescent probe for detection of fluoride ion and hydrazine based on test strips
摘要： Hydrazine (N2H4) and fluoride ion (F-) are regarded as environmental pollutants and potential carcinogens. A dual-functional fluorescent probe (probe 1) was developed for both F- and N2H4 with high selectivity and sensitivity. 1 was based on nucleophilic aromatic substitution reaction for N2H4 detection and selective cleavage of 4-nitrobenzenesulphonyl group for the determination of F-. The limits of detection of probe for F- and N2H4 were 77.82 nM and 29.34 nM, respectively, which are far below the threshold limit value (TLV) of United States Environmental Protection Agency (EPA). The home-made test strips of 1 provided the positive tool for F- and gaseous N2H4 in different system. And the confocal fluorescence images indicated that 1 can quantitatively detect N2H4 in living PC12 cells. Promisingly, 1 has great prospects for N2H4 imaging and determining in living system.
关键词： Living cells,Fluoride ion,Dual-functional fluorescent probe,Hydrazine,Home-made test strips
更新于2025-09-10 09:29:36
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Bending Limit Tests for Ultra-Thin Liquid Crystal Polymer Substrate Based on Flexible Microwave Components
摘要： In this paper, bending limit tests for one ultra-thin liquid crystal polymer (LCP) substrate (Rogers 3850) based on the mechanical properties of ?exible microwave microstrip components are presented. First, a set of 50 ? microstrip lines, a band-pass ?lter, and a stepped impedance ?lter in X-band, are designed by using double clapped LCPs with 50 μm thickness of substrate and 18 μm thickness of copper, which is fabricated by conventional photolithography. Then, the limit tests of the ?exibility of the LCP microwave microstrip components are presented, and the range of the bending limit radius, from 1 mm to 0.75 mm, is demonstrated from the testing results. It is found that the cause for component failure is fracture of the copper (18 μm thickness) laminate, according to the bending limit test experiments. Finally, the analysis of the reasons for the collapse of the microwave components, under bending situations, is explored. The results from this work would be useful for further designs of the ?exible microwave devices and systems on LCP substrates, with compact sizes and good performance.
关键词： microwave components,?exible ?lters,bending limit test,bending effect,LCP substrate
更新于2025-09-10 09:29:36
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Implementing a method based on near infrared spectroscopy for the “in-situ” determination of ammonia/water composition in an absorber test bench
摘要： This study presents the first results of composition measurement in an ammonia/water mixture determined at real time using near-infrared (NIR) spectroscopy in an absorber test bench. Two cells were designed and constructed; a static cell for calibrating and a dynamic cell for measuring in the absorber test bench. The ammonia absorption band was not significantly affected by the solution flow rate and neither by small variations in the temperature and pressure. A linear regression model between the absorbance value at 1033 nm and the ammonia concentration was established. This model was used to estimate the concentration in an ammonia/water absorber test bench. The methodology was validated by density measurements of the samples. The value of the mean deviation was 0.0024.
关键词： ammonia/water composition,near-infrared spectroscopy,absorber test bench,real-time measurement
更新于2025-09-10 09:29:36
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A cyclometalated iridium(III) complex-based fluorescence probe for hypochlorite detection and its application by test strips
摘要： A new cyclometalated iridium(III) complex-based fluorescence probe (IrCN) for hypochlorite (ClO?) has been synthesized and characterized. The probe displayed nonfluorescent around 577 nm, while a 54-fold enhancement in fluorescence emission intensity was observed after the addition of ClO? due to the removal of C=N isomerization effect. Such “turn-on” fluorescence probe worked excellently in wide pH range (5–12) with short response time (< 20 s) and the detection limit was as low as 0.11 μM. In addition, IrCN exhibited high selectivity even in the presence of other competing species. Furthermore, IrCN was successfully integrated in towards ClO? fluorescent test strips for real-time detection of ClO?.
关键词： Fluorescence probe,Iridium(III) complex,Test strips,Hypochlorite
更新于2025-09-09 09:28:46
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Thermal Shock Performance of DBA/AMB Substrates Plated by Ni and Ni–P Layers for High-Temperature Applications of Power Device Modules
摘要： The thermal cycling life of direct bonded aluminum (DBA) and active metal brazing (AMB) substrates with two types of plating—Ni electroplating and Ni–P electroless plating—was evaluated by thermal shock tests between ?50 and 250 ?C. AMB substrates with Al2O3 and AlN fractured only after 10 cycles, but with Si3N4 ceramic, they retained good thermal stability even beyond 1000 cycles, regardless of the metallization type. The Ni layer on the surviving AMB substrates with Si3N4 was not damaged, while a crack occurred in the Ni–P layer. For DBA substrates, fracture did not occur up to 1000 cycles for all kind of ceramics. On the other hand, the Ni–P layer was roughened and cracked according to the severe deformation of the aluminum layer, while the Ni layer was not damaged after thermal shock tests. In addition, the deformation mechanism of an Al plate on a ceramic substrate was investigated both by microstructural observation and ?nite element method (FEM) simulation, which con?rmed that grain boundary sliding was a key factor in the severe deformation of the Al layer that resulted in the cracking of the Ni–P layer. The fracture suppression in the Ni layer on DBA/AMB substrates can be attributed to its ductility and higher strength compared with those of Ni–P plating.
关键词： DBA,cracking,Ni–P electroless plating,Ni electroplating,reliability,grain boundary sliding,AMB,thermal shock test,roughness,metallization
更新于2025-09-09 09:28:46
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Study of memory deficit in Alzheimer’s disease by means of complexity analysis of fNIRS signal
摘要： Working memory deficit is a signature of Alzheimer’s disease (AD). The free and cued selective reminding test (FCSRT) is a clinical test that quantifies memory deficit for AD diagnosis. However, the diagnostic accuracy of FCSRT may be increased by accompanying it with neuroimaging. Since the test requires doctor–patient interaction, brain monitoring is challenging. Functional near-infrared spectroscopy (fNIRS) could be suited for such a purpose because of the fNIRS flexibility. We investigated whether the complexity, based on sample entropy and multiscale entropy metrics, of the fNIRS signal during FCSRT was correlated with memory deficit in early AD. fNIRS signals were recorded over the prefrontal cortex of healthy and early AD participants. Group differences were tested through Wilcoxon–Mann–Whitney test (p < 0.05). At group level, we found significant differences for Brodmann areas 9 and 46. The results, although preliminary, demonstrate the feasibility of performing ecological studies on early AD with fNIRS. This approach may provide a potential neuroimaging-based method for diagnosis of early AD, viable at the doctor’s office level, improving test-based diagnosis. The increased entropy of the fNIRS signal in early AD suggests the opportunity for further research on the neurophysiological status in AD and its relevance for clinical symptoms.
关键词： entropy,functional near-infrared spectroscopy,Alzheimer’s disease,free and cued selective reminding test
更新于2025-09-09 09:28:46
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[IEEE 2018 34th International Conference on Lightning Protection (ICLP) - Rzeszow (2018.9.2-2018.9.7)] 2018 34th International Conference on Lightning Protection (ICLP) - On In Situ Lightning Current Impulse Testing in a Large Free Field PV Plant
摘要： Lightning ground potential rise (GPR) was shown to be a significant contributor to equipment damage under certain conditions that include, in particular, high soil resistivity. In addition, IEEE Std 1692 suggested that surge protective devices (SPDs) may not protect adequately under conditions of lightning GPR. This paper follows on earlier work that addressed lightning GPR associated with large electrodes, loss of equipotential under conditions of GPR and a desk-top study on the behavior of a low voltage SPD under emulated lightning impulse conditions. The findings of a laboratory test on the behavior of an SPD under lightning current impulse conditions as well as in situ testing of an SPD under lightning current impulse are presented in this paper. The paper concludes by reflecting on initial findings from post-test monitoring under actual lightning, emphasizes the value of in situ testing and points out its limitations.
关键词： current,lightning,free field,in situ,plant,test,photovoltaic,impulse
更新于2025-09-09 09:28:46
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Mix-&-Read Determination of Mercury(II) at Trace Levels with Hybrid Mesoporous Silica Materials Incorporating Fluorescent Probes by a Simple Mix-&-Load Technique
摘要： The synthesis, characterization, and application of mesoporous materials containing boron–dipyrromethene (BODIPY) moieties that allow the sensitive and selective detection of HgII in aqueous environments by fluorescence enhancement is reported. For this purpose, BODIPY dye I containing a thia-aza crown ether receptor as the fluorescent probe for the detection of HgII in aqueous environments is encapsulated into mesoporous materials to avoid self-quenching or aggregation in water. Determination of HgII is accomplished within a few seconds with high selectivity and sensitivity, reaching a limit of detection of 12 ppt. The determination of trace amounts of HgII in natural waters and in fish extracts is demonstrated by using our sensing material. The incorporation of the material into several m-PAD strips yields a portable, cheap, quick, and easy-to-handle tool for trace HgII analysis in water.
关键词： dyes/pigments,mercury,fluorescence,mesoporous materials,test strips
更新于2025-09-09 09:28:46
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Performance evaluation of IR-UWB detectors and fusion techniques for UWB transceiver platforms
摘要： In this paper, we analyse the performance of a multi-pulse impulse radio based ultra-wideband (IR-UWB) detector in an AWGN setting and provide different fusion strategies for fusing these detector outputs. To enable the transceiver to be used for multiple applications, the designers have different types of detectors such as energy detectors, amplitude detectors, etc., built in to a single transceiver architecture. In this paper, we derive the detection performance equation for commonly used detectors in terms of false alarm rate, shape of the pulse, and number of UWB pulses used in the detection and apply these in the fusion algorithms. We show that the performance can be improved by approximately 4 dB in terms of signal to noise ratio (SNR) for high probability of detection of a UWB signal (95%), by fusing decisions from multiple detector types compared to a standalone energy detector, in a practical scenario.
关键词： UWB ranging,TOA,sensor networks,time of arrival,UWB,ultra wideband,Neyman-Pearson test
更新于2025-09-09 09:28:46