A D-type photonic crystal fiber(PCF) sensor based on surface plasmon resonance(SPR) principle is designed.In order to excite the SPR effect,a gold film is plated on the open-loop channel of the sensor,the free electro...A D-type photonic crystal fiber(PCF) sensor based on surface plasmon resonance(SPR) principle is designed.In order to excite the SPR effect,a gold film is plated on the open-loop channel of the sensor,the free electrons in a metal are resonated with photons.The structural parameters are fine-tuned and the sensing performance of the sensor is studied.The results show that the maximum spectral sensitivity reaches 18 000 nm/RIU in the refractive index range of 1.24—1.32,and the maximum resolution is 5.56×10^(-6) RIU.The novel structure with high sensitivity and low refractive index provides a new perspective for fluid density detection.展开更多
Electronic skin has showcased superior sensing capabilities inspired from human skin.However,most preceding studies focused on the dermis of the skin rather than the epidermis.In particular,the pseudo-porous structura...Electronic skin has showcased superior sensing capabilities inspired from human skin.However,most preceding studies focused on the dermis of the skin rather than the epidermis.In particular,the pseudo-porous structural domain of the epidermis increases the skin's tolerance while ensuring its susceptibility to touch.Yet,most endeavors on the porous structures failed to replicate the superior sensing performance of skin-like counterparts in terms of sensitivity and/or detection range.Stimulated by the strategy that the epidermis of the skin absorbs energy while producing ionic conduction to the nerves,this work initiatively introduced an easy-to-produce,and low-cost pressure sensor based on ionic-gel foam,and achieved a high sensitivity(2893 kPa^(-1))within a wide pressure range(up to~1 MPa),which ranked among the best cases thus far.Moreover,the factors affecting the sensor performance were explored while the sensing principles were enriched.Inspiringly,the plantar pressure measurement by harnessing the as-prepared sensor unveiled an ultra-broad detection range(100 Pa-1 MPa),thus delivering a huge application potential in the field of robot and health monitoring.展开更多
Flexible piezoresistive sensors based on biomimetic microstructures are prospective for broad application in motion monitoring.However,the design and preparation processes of most biomimetic microstructures in the exi...Flexible piezoresistive sensors based on biomimetic microstructures are prospective for broad application in motion monitoring.However,the design and preparation processes of most biomimetic microstructures in the existing studies are complicated,and there are few studies on pore size control.Herein,the porous structure of human bones was used as a biomimetic prototype,and optimally designed by creating a theoretical equivalent sensor model and a finite element model.Soluble raw materials such as sugar and salt in different particle sizes were pressed into porous templates.Based on the template method,porous structures in different pore sizes were prepared using polydimethylsiloxane(PDMS)polymer as the substrate.On this basis,graphene oxide conductive coating was prepared with the modified Hummers method and then deposited via dip coating onto the substrate.Finally,a PDMS-based porous structure biomimetic flexible piezoresistive sensor was developed.Mechanically,the deformation of the sensor under the same load increased with the pore size rising from 0.3 to 1.5 mm.Electrically,the resistance rang of the sensor was enlarged as the pore size rose.The resistance variation rates of samples with pore sizes of 0.3,1.0,and 1.5 mm at approximately the 200th cycle were 63%,79%,and 81%,respectively;at the 500th cycle,these values were 63%,77%,and 79%;and at the 1000th cycle,they stabilized at 63%,74%,and 76%.These results indicate that the fabricated sensor exhibits high stability and fatigue resistance.At the pressure of 0–25 kPa,the sensitivity rose from 0.0688 to 0.1260 kPa−1,and the performance was enhanced by 83%.After 1,000 cycles of compression testing,the signal output was stable,and no damage was caused to the substrate.Further application tests showed the biomimetic sensor accurately and effectively identified human joint motions and gestures,and has potential application value in human motion monitoring.展开更多
High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneous...High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneously achieve high sensitivity,a wide detection range,and good mechanical stability remains a challenge.In this paper,we propose a flexible piezoresistive pressure sensor based on a Ti_(3)C_(2)Tx(MXene)/polyethylene oxide(PEO)composite nanofiber membrane(CNM).The sensor,utilizing MXene(0.4 wt%)/PEO(5 wt%),exhibits high sensitivity(44.34 kPa^(−1)at 0−50 kPa,12.99 kPa^(−1)at 50−500 kPa)and can reliably monitor physiological signals and other subtle cues.Moreover,the sensor features a wide detection range(0−500 kPa),fast response and recovery time(~150/45 ms),and excellent mechanical stability(over 10000 pressure cycles at maximum load).Through an MXene/PEO sensor array,we demonstrate its applications in human physiological signal monitoring,providing a reliable way to expand the application of MXene-based flexible pressure sensors.展开更多
High-temperature thin-film strain sensors are advanced technological devices for monitoring stress and strain in extreme environments,but the coupling of temperature and strain at high temperature is a challenge for t...High-temperature thin-film strain sensors are advanced technological devices for monitoring stress and strain in extreme environments,but the coupling of temperature and strain at high temperature is a challenge for their use.Here,this issue is addressed by creating a composite ink that combines Pb_(2)Ru_(2)O_(6) and TiB_(2) using polysilazane(PSZ)as a binder.After direct writing and annealing the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film at 800℃ in air,the resulting thin film exhibits a low temperature coefficient of resistance(TCR)of only 281 ppm/℃ over a wide temperature range from 100℃ to 700℃,while also demonstrating high sensitivity with a gauge factor approaching 19.8.This exceptional performance is attributed to the intrinsic properties of Pb_(2)Ru_(2)O_(6),which has positive TCR at high temperature,and TiB2,which has negative TCR at high temperature.Combining these materials reduces the overall TCR of the film.Tests showed that the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film maintains stable strain responses and significant signal output even under varying temperature.These findings provide valuable insights for developing high-temperature strain sensors with low TCR and high sensitivity,highlighting their potential for applications in high-temperature strain measurements.展开更多
Background The data on the prognostic values of high sensitivity C-reactive protein （hsCRP） levels in patients with advanced symp-tomatic heart failure （HF） receiving cardiac resynchronization therapy （CRT） are ...Background The data on the prognostic values of high sensitivity C-reactive protein （hsCRP） levels in patients with advanced symp-tomatic heart failure （HF） receiving cardiac resynchronization therapy （CRT） are scarce. The aim of present study was to investigate the association of serum hsCRP levels with left ventricle reverse remodeling after six months of CRT as well as long-term outcome. Methods A total of 232 CRT patients were included. The assessment of hsCRP values, clinical status and echocardiographic data were performed at baseline and after six months of CRT. Long-term follow-up included all-cause mortality and hospitalizations for HF. Results During the mean follow-up periods of 31.3 ± 31.5 months, elevated hsCRP （〉3 mg/L） prior to CRT was associated with a significant 2.39-fold increase （P=0.006） in the risk of death or HF hospitalizations. At 6-month follow-up, patients who responded to CRT showed significant reductions or maintained low in hsCRP levels （–0.5 ± 4.1 mg/L reduction） compared with non-responders （1.7 ± 6.1 mg/L increase, P=0.018）. Com-pared with patients in whom 6-month hsCRP levels were reduced or remained low, patients in whom 6-month hsCRP levels were increased or maintained high experienced a significantly higher risk of subsequent death or HF hospitalizations （Log-rank P〈0.001）. The echocardio-graphic improvement was also better among patients in whom 6-month hsCRP levels were reduced or remained low compared to those in whom 6-month hsCRP levels were raised or maintained high. Conclusions Our findings demonstrated that measurement of baseline and follow-up hsCRP levels may be useful as prognostic markers for timely potential risk stratification and subsequent appropriate treatment strategies in patients with advanced HF undergoing CRT.展开更多
With the prosperous development of artificial intelligence,medical diagnosis and electronic skins,wearable electronic devices have drawn much attention in our daily life.Flexible pressure sensors based on carbon mater...With the prosperous development of artificial intelligence,medical diagnosis and electronic skins,wearable electronic devices have drawn much attention in our daily life.Flexible pressure sensors based on carbon materials with ultrahigh sensitivity,especially in a large pressure range regime are highly required in wearable applications.In this work,graphene membrane with a layer-by-layer structure has been successfully fabricated via a facile self-assembly and air-drying(SAAD)method.In the SAAD process,air-drying the self-assembled graphene hydrogels contributes to the uniform and compact layer structure in the obtained membranes.Owing to the excellent mechanical and electrical properties of graphene,the pressure sensor constructed by several layers of membranes exhibits high sensitivity(52.36 kPa……-1)and repeatability(short response and recovery time)in the loading pressure range of 0–50 kPa.Compared with most reported graphene-related pressure sensors,our device shows better sensitivity and wider applied pressure range.What’s more,we demonstrate it shows desired results in wearable applications for pulse monitoring,breathing detection as well as different intense motion recording such as walk,run and squat.It’s hoped that the facilely prepared layer-by-layer graphene membrane-based pressure sensors will have more potential to be used for smart wearable devices in the future.展开更多
In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances i...In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances in terms of data channel coding which might result in a signal structure where the symbol duration is shorter than the pseudo code period. This can generate some difficulties in the DSSS signal acquisition due to the polarity inversion caused by the data modulation. To eliminate the influence due to polarity inversion, this paper proposes a novel acquisition algorithm based on the simultaneous search of the code phase, data phase and Doppler frequency. In the proposed algorithm the data phase is predicted and the correlation period for the coherent integration can be set equal to the symbol duration. Then non-coherent accumulation over different symbol is implemented in order to enhance the acquisition algorithm sensitivity; the interval of non-coherent accumulation is the least common multiple between the symbol duration and the pseudo code period. The algorithm proposed can largely minimize the SNR loss caused by data polarity inversion and enhance acquisition performance without a noticeable increase in hardware complexity. Theoretical analysis, simulation and measured results verify the validity of the algorithm.展开更多
A dual emission sensing film has been prepared for colorimetric temperature sensing using CsPbBr_(3)perovskite nanocrystals(CsPbBr_(3)NCs)and manganese doped potassium fluorosilicate(K_(2)SiF_(6):Mn^(4+),KSF)encapsula...A dual emission sensing film has been prepared for colorimetric temperature sensing using CsPbBr_(3)perovskite nanocrystals(CsPbBr_(3)NCs)and manganese doped potassium fluorosilicate(K_(2)SiF_(6):Mn^(4+),KSF)encapsulated in polystyrene by a microencapsulation strategy.The CsPbBr_(3)-KSF-PS film shows good temperature sensing response from 30℃to 70℃,with a relative temperature sensitivity(Sr)up to 10.31%℃^(−1) at 45℃.Meanwhile,the film maintains more than 95%intensity after 6 heating-cooling cycles and keeps its fluorescence characteristics after 3 months.The film can be used to monitor temperature change by naked eye under a UV lamp.In particular,the temperature discoloration point of the sensing film can be controlled by the ratio change of CsPbBr_(3):KSF to expand its applications.The study of the CsPbBr_(3)-KSF-PS sensing mechanism in this work is helpful to provide effective strategies for the design of reliable,high sensitivity and stable temperature sensing system using CsPbBr_(3)NCs.展开更多
Based on geometric moire method, moire interferometry and microscopic moire interferometry, a high spatial resolution and high sensitivity geometric microscopic moire method is presented. Geometric micron-moire patter...Based on geometric moire method, moire interferometry and microscopic moire interferometry, a high spatial resolution and high sensitivity geometric microscopic moire method is presented. Geometric micron-moire patterns are produced by the superposition of two high frequency gratings through a microscope system. Compared with other grating-based photo-mechanics methods, microscopic moire method could provide whole-field moire patterns of both high spatial resolution and high sensitivity. The frequency of specimen and reference gratings used in this method can be from 1 line/mm to 10000 lines/mm. Additionally, a 4F optical filter system is used to enhance the contrast of microscopic moire patterns effectively.展开更多
Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the application...Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the applications of flexible PSDs have been limited.Therefore,we presented a flexible broadband PSD based on a WS_(2)/Si heterostructure for the first time.A scalable sputtering method was used to deposit WS_(2)thin films onto the etched ultrathin crystalline Si surface.The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450-1350 nm,with a high position sensitivity of~539.8 mV·mm^(−1)and a fast response of 2.3μs,thanks to the strong light absorption,the built-in electrical field at the WS_(2)/Si interface,and facilitated transport.Furthermore,mechanical-bending tests revealed that after 200 mechanical-bending cycles,the WS_(2)/Si PSDs have excellent mechanical flexibility,stability,and durability,demonstrating the great potential in wearable PSDs with competitive performance.展开更多
Background Coronary artery disease(CAD)remains a leading cause of morbidity and mortality.Cytokines play a potential role in atherosclerosis pathogenesis and progression.We investigated the association between high se...Background Coronary artery disease(CAD)remains a leading cause of morbidity and mortality.Cytokines play a potential role in atherosclerosis pathogenesis and progression.We investigated the association between high sensitive C-reactive protein(hs CRP)and severity of CAD.Methods CAD patients were stratified according to hs CRP cut-off value into high levels hs CRP group(≥8.4 mg/L)and low levels hs CRP group(<8.4 mg/L).Severity of CAD was assessed according to artery stenosis degree and the number of vessel involved.Statistical analysis was performed using Statistical Package for the Social Sciences(SPSS,version 23.0).Results The mean age was 60.3±11.0 years.The level of hs CRP was increased and ranged from 0.2 to 1020.0 mg/L.Biochemical risk factors and severity of CAD didn’t show significant differences between the two groups.In multivariate linear analysis,cardiac troponin I(c Tn I)and serum amyloid A(SAA)were predictors of hs CRP.As shown in receiver operating characteristic(ROC)curve analysis performed in patients with ST-segment elevation myocardial infarction(STEMI)and compared to myonecrosis biomarkers,hs CRP(area under the curve(AUC):0.905;95%CI:0.844-0.966;P<0.001)could be a powerful predictor marker in evaluating the infarct size after myocardial infarction but not better than c Tn I.Conclusions Hs CRP levels were not associated with the severity of CAD but could be useful in the evaluation of myocardial necrosis in patients with STEMI.展开更多
Structurally simple salicylaldehyde-based fluoreseent sensors for amino acids have been obtained by one-step or two-step synthesis.These sensors show significant fluorescence enhancement in the presence of many amino ...Structurally simple salicylaldehyde-based fluoreseent sensors for amino acids have been obtained by one-step or two-step synthesis.These sensors show significant fluorescence enhancement in the presence of many amino acids at concentrations as low as 10~5 mol/L.The reversible reaction of the aldehydes with amino acids to form imines in aqueous solution is proposed to account for the observed fluorescence enhancement.展开更多
Biomarkers are early predictors of various disorders, circulating level of C-reactive protein is a sensitive biomarker of systemic inflammation and may also be associated with the development of diabetic, hepatic, and...Biomarkers are early predictors of various disorders, circulating level of C-reactive protein is a sensitive biomarker of systemic inflammation and may also be associated with the development of diabetic, hepatic, and cardiovascular diseases. In the present study, we aimed to investigate the association between circulating levels of high sensitive C-reactive protein (hs-CRP) and various biomarkers for hepatic, diabetic, and cardiovascular health. The retrospective analysis included 438 individuals who were tested for these panels simultaneously at Vibrant America Clinical Laboratory. The study population included free-living individuals without any preexisting clinical conditions. Among the cardiovascular markers, a positive correlation and significant association was found between high levels of hs-CRP and serum levels of triglycerides (r = 0.0964, p −0.1423, p −0.1216, p < 0.0105) with circulating levels of hs-CRP. Among all the diabetic markers, glucose (r = 0.1547, p < 0.0011) and glycated serum protein (r = 0.1725, p < 0.0003) were positively correlated with circulating hs-CRP. In the hepatic panel, AST, a transaminase that plays a vital role in amino acid metabolism, was found to have a strong positive correlation with hs-CRP (r = 0.2139, p < 0.0001). In conclusion, the results clearly show the association of hs-CRP with diabetic, hepatic, and cardiovascular risk factors indicating its central value as a key marker for several lifestyle-associated disorders.展开更多
High-sensitivity sensors represent a critical frontier in modern sensing technology,driving innovations across fields such as biomedical monitoring,precision instrumentation,environmental detection,and indus-trial aut...High-sensitivity sensors represent a critical frontier in modern sensing technology,driving innovations across fields such as biomedical monitoring,precision instrumentation,environmental detection,and indus-trial automation.As demands for accuracy,miniaturization,and reliability continue to grow,developing novel sensor architectures and functional materials has become essential to achieving enhanced performance under extreme or complex conditions.展开更多
Respiratory rate monitoring is of great significance in pig healthy breeding for the early detection and timely prevention of respiratory diseases.Humidity sensing is an important noncontact method to monitor pig resp...Respiratory rate monitoring is of great significance in pig healthy breeding for the early detection and timely prevention of respiratory diseases.Humidity sensing is an important noncontact method to monitor pig respiration,which does not cause direct harm to pigs and meets the requirements of animal welfare.This paper proposes a humidity sensor based on graphene oxide wrapped-silica microspheres(GO@SiO_(2)).First,the sensor shows fast response/recovery performances of 0.24/0.73 s.Experiments demonstrate that the wrapped microsphere structure can inhibit water aggregation.It is speculated that the wrapped microsphere structure can inhibit the stacking of GO,and its curved surface can promote the evaporation of water molecules.Second,the sensor shows a high sensitivity of 1.2%/%RH-4.2%/%RH in 11%-95%RH range.This can be attributed to different sensing mechanisms,from hopping transport to increasing ion transport,leading to a significant change in the sensor’s resistance.Third,the sensor shows selectivity to water molecules due to the hydrophilic characteristic of GO and the significant increase in conductivity by ion transport.Finally,the sensor is applied to realize the respiratory rate monitoring of adult pigs and piglets.展开更多
Background The relationship between inflammatory markers and the characteristics of coronary atherosclerosis plaques is uncertain. The aim of the present study was to evaluate the relationship between the characterist...Background The relationship between inflammatory markers and the characteristics of coronary atherosclerosis plaques is uncertain. The aim of the present study was to evaluate the relationship between the characteristics of coronary atherosclerosis plaques and inflammatory markers such as high sensitivity C-reactive proteins （Hs-CRP） and interleukin-6 （IL-6）. Methods All patients suspected of having coronary heart disease （CHD） underwent Siemens 64-slice CT angiography （64-SCTA） to distinguish the quality of plaque of coronary artery lesions. Blood samples were taken to measure levels of serum Hs-CRP and IL-6 in different plaque groups and the control group and compared with the value of 64-SCTA for detection of coronary artery plaque. Results The sensitivity of detecting coronary artery plaque by 64-SCTA was 87.4%, the specificity was 87.1%, the positive predictive value was 82.2%, and the negative predictive value was 91.0%. Comparing the levels of serum Hs-CRP and IL-6 among plaque groups, the mean levels of serum Hs-CRP and IL-6 in three plaque groups were significantly higher than those in the control group （P 〈0.01）. The mean levels of serum Hs-CRP and IL-6 in the soft plaque group and mixed plaque group were significantly higher than those in hard plaque group （P〈0.01）. Plaque burden in the soft plaque group and mixed plaque group was significantly higher than in the hard plaque group （P 〈0.01）, but there was no statistical difference between the soft plaque group and mixed plaque group （P=-0.246）. There was a negative correlation between the CT scale and Hs-CRP and IL-6 levels in the soft plaque group （r= -0.621, P〈0.01, and r= -0.593, P 〈0.01 respectively）. There was a positive correlation between the plaque burden and Hs-CRP and IL-6 levels in the soft plaque group （r=0.579, P〈0.05 and r=0.429, P〈0.05 respectively）. Conclusions 64-SCTA is an effective way to distinguish the different quality of coronary atherosclerosis plaque. Serum Hs-CRP and IL-6 levels can be considered as the indexes to judge the degree of CHD and may reflect the activity of plaque in CHD patients. Thus it is important for clinical diagnosis and risk evaluation of acute coronary syndrome （ACS） patients.展开更多
Background Inflammation within vulnerable coronary plaques may cause unstable angina by promoting rupture and erosion. C-reactive protein （CRP） is the most reliable and accessible test method for clinical use for id...Background Inflammation within vulnerable coronary plaques may cause unstable angina by promoting rupture and erosion. C-reactive protein （CRP） is the most reliable and accessible test method for clinical use for identifying coronary artery disease event. Matrix metalloproteinase 9 （MMP-9） is highly over-expressed in the vulnerable regions of a plaque. Our aim was to evaluate the plasma levels of MMP-9 and hsCRP in subjects with both unstable angina and coronary plaques, as well as in those with unstable angina without coronary plaques.展开更多
Tunable diode laser absorption spectroscopy （TDLAS） has been widely employed in atmospheric trace gases detection. In the measurement of these trace gases, harmonic detection combined with a multi-pass white cell co...Tunable diode laser absorption spectroscopy （TDLAS） has been widely employed in atmospheric trace gases detection. In the measurement of these trace gases, harmonic detection combined with a multi-pass white cell could remarkably enhance the detection sensitivity. In this paper, a portable TDLAS system built specifically for long time monitoring methane in the atmosphere is introduced. The detection limit is below 100 ppb that is enough for the monitoring of ambient methane, and the long time monitoring results obtained in Beijing are given, which is well coincident with that of the Fourier transform infrared （FTIR） spectroscopy.展开更多
We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spec...We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spectrocopy.The first method is employed to derive a metastasis lung tissue imaging at 3.7 THz with clear contrast between cancerous and healthy areas.The second approach is used to study an osseous tissue under several imaging modalities and achieve full THz spectroscopic imaging based on the frequency domain or on a fixed THz propagation time-delay.Sufficient contrast is achieved which facilitated the identification of regions with different cellular types and density compositions.展开更多
基金supported by the Natural Science Foundation of Tianjin City (No.19JCYBJC17000)the National Natural Science Foundation of China (No.11905159)。
文摘A D-type photonic crystal fiber(PCF) sensor based on surface plasmon resonance(SPR) principle is designed.In order to excite the SPR effect,a gold film is plated on the open-loop channel of the sensor,the free electrons in a metal are resonated with photons.The structural parameters are fine-tuned and the sensing performance of the sensor is studied.The results show that the maximum spectral sensitivity reaches 18 000 nm/RIU in the refractive index range of 1.24—1.32,and the maximum resolution is 5.56×10^(-6) RIU.The novel structure with high sensitivity and low refractive index provides a new perspective for fluid density detection.
基金supported the Chongqing Natural Science Foundation(CSTB2023NSCQ-MSX0459&CSTB2023NSCQ-MSX0231)the Graduate Research and Innovation Foundation of Chongqing,China(CYB23048)+1 种基金the Fundamental Research Program under Grant(JCKY2022603C017)National Natural Science Foundation of China(NSFC 52175281).
文摘Electronic skin has showcased superior sensing capabilities inspired from human skin.However,most preceding studies focused on the dermis of the skin rather than the epidermis.In particular,the pseudo-porous structural domain of the epidermis increases the skin's tolerance while ensuring its susceptibility to touch.Yet,most endeavors on the porous structures failed to replicate the superior sensing performance of skin-like counterparts in terms of sensitivity and/or detection range.Stimulated by the strategy that the epidermis of the skin absorbs energy while producing ionic conduction to the nerves,this work initiatively introduced an easy-to-produce,and low-cost pressure sensor based on ionic-gel foam,and achieved a high sensitivity(2893 kPa^(-1))within a wide pressure range(up to~1 MPa),which ranked among the best cases thus far.Moreover,the factors affecting the sensor performance were explored while the sensing principles were enriched.Inspiringly,the plantar pressure measurement by harnessing the as-prepared sensor unveiled an ultra-broad detection range(100 Pa-1 MPa),thus delivering a huge application potential in the field of robot and health monitoring.
基金supported by the National Natural Science Foundation of China(52175270)the Project of Scientifc and Technological Development Plan of Jilin Province(20220508130RC)+3 种基金the Science and Technology Development Program of Jilin Province(YDZJ202501ZYTS370)the Scientific Research Project of Education Department of Jilin Province(JJKH20251196KJ)the Scientific Research Project of Education Department of Jilin Province(JJKH20251195KJ)the Key Project of State Key Laboratory of Changchun City(23GZZ14).
文摘Flexible piezoresistive sensors based on biomimetic microstructures are prospective for broad application in motion monitoring.However,the design and preparation processes of most biomimetic microstructures in the existing studies are complicated,and there are few studies on pore size control.Herein,the porous structure of human bones was used as a biomimetic prototype,and optimally designed by creating a theoretical equivalent sensor model and a finite element model.Soluble raw materials such as sugar and salt in different particle sizes were pressed into porous templates.Based on the template method,porous structures in different pore sizes were prepared using polydimethylsiloxane(PDMS)polymer as the substrate.On this basis,graphene oxide conductive coating was prepared with the modified Hummers method and then deposited via dip coating onto the substrate.Finally,a PDMS-based porous structure biomimetic flexible piezoresistive sensor was developed.Mechanically,the deformation of the sensor under the same load increased with the pore size rising from 0.3 to 1.5 mm.Electrically,the resistance rang of the sensor was enlarged as the pore size rose.The resistance variation rates of samples with pore sizes of 0.3,1.0,and 1.5 mm at approximately the 200th cycle were 63%,79%,and 81%,respectively;at the 500th cycle,these values were 63%,77%,and 79%;and at the 1000th cycle,they stabilized at 63%,74%,and 76%.These results indicate that the fabricated sensor exhibits high stability and fatigue resistance.At the pressure of 0–25 kPa,the sensitivity rose from 0.0688 to 0.1260 kPa−1,and the performance was enhanced by 83%.After 1,000 cycles of compression testing,the signal output was stable,and no damage was caused to the substrate.Further application tests showed the biomimetic sensor accurately and effectively identified human joint motions and gestures,and has potential application value in human motion monitoring.
基金support from Beijing Natural Science Foundation−Xiaomi Innovation Joint Fund(Grant No.L233009)the National Natural Science Foundation of China(NSFC Grant Nos.62422409,62174152 and 62374159)from the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2020115).
文摘High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneously achieve high sensitivity,a wide detection range,and good mechanical stability remains a challenge.In this paper,we propose a flexible piezoresistive pressure sensor based on a Ti_(3)C_(2)Tx(MXene)/polyethylene oxide(PEO)composite nanofiber membrane(CNM).The sensor,utilizing MXene(0.4 wt%)/PEO(5 wt%),exhibits high sensitivity(44.34 kPa^(−1)at 0−50 kPa,12.99 kPa^(−1)at 50−500 kPa)and can reliably monitor physiological signals and other subtle cues.Moreover,the sensor features a wide detection range(0−500 kPa),fast response and recovery time(~150/45 ms),and excellent mechanical stability(over 10000 pressure cycles at maximum load).Through an MXene/PEO sensor array,we demonstrate its applications in human physiological signal monitoring,providing a reliable way to expand the application of MXene-based flexible pressure sensors.
基金the National Key Research and Development Program of China(Grant No.2021YFB2012100)the Major Science and Technology Projects in Fujian Province(Grant No.2023HZ021005)+1 种基金the Open Project Program of Fujian Key Laboratory of Special Intelligent Equipment Measurement and Control(Grant No.FJIES2023KF06)the Industry-University-Research Co-operation Fund of the Eighth Research Institute of China Aerospace Science and Technology Corporation(Grant No.SAST2023-061).
文摘High-temperature thin-film strain sensors are advanced technological devices for monitoring stress and strain in extreme environments,but the coupling of temperature and strain at high temperature is a challenge for their use.Here,this issue is addressed by creating a composite ink that combines Pb_(2)Ru_(2)O_(6) and TiB_(2) using polysilazane(PSZ)as a binder.After direct writing and annealing the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film at 800℃ in air,the resulting thin film exhibits a low temperature coefficient of resistance(TCR)of only 281 ppm/℃ over a wide temperature range from 100℃ to 700℃,while also demonstrating high sensitivity with a gauge factor approaching 19.8.This exceptional performance is attributed to the intrinsic properties of Pb_(2)Ru_(2)O_(6),which has positive TCR at high temperature,and TiB2,which has negative TCR at high temperature.Combining these materials reduces the overall TCR of the film.Tests showed that the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film maintains stable strain responses and significant signal output even under varying temperature.These findings provide valuable insights for developing high-temperature strain sensors with low TCR and high sensitivity,highlighting their potential for applications in high-temperature strain measurements.
文摘Background The data on the prognostic values of high sensitivity C-reactive protein （hsCRP） levels in patients with advanced symp-tomatic heart failure （HF） receiving cardiac resynchronization therapy （CRT） are scarce. The aim of present study was to investigate the association of serum hsCRP levels with left ventricle reverse remodeling after six months of CRT as well as long-term outcome. Methods A total of 232 CRT patients were included. The assessment of hsCRP values, clinical status and echocardiographic data were performed at baseline and after six months of CRT. Long-term follow-up included all-cause mortality and hospitalizations for HF. Results During the mean follow-up periods of 31.3 ± 31.5 months, elevated hsCRP （〉3 mg/L） prior to CRT was associated with a significant 2.39-fold increase （P=0.006） in the risk of death or HF hospitalizations. At 6-month follow-up, patients who responded to CRT showed significant reductions or maintained low in hsCRP levels （–0.5 ± 4.1 mg/L reduction） compared with non-responders （1.7 ± 6.1 mg/L increase, P=0.018）. Com-pared with patients in whom 6-month hsCRP levels were reduced or remained low, patients in whom 6-month hsCRP levels were increased or maintained high experienced a significantly higher risk of subsequent death or HF hospitalizations （Log-rank P〈0.001）. The echocardio-graphic improvement was also better among patients in whom 6-month hsCRP levels were reduced or remained low compared to those in whom 6-month hsCRP levels were raised or maintained high. Conclusions Our findings demonstrated that measurement of baseline and follow-up hsCRP levels may be useful as prognostic markers for timely potential risk stratification and subsequent appropriate treatment strategies in patients with advanced HF undergoing CRT.
基金Financial support from the grant from the City University of Hong Kong(SRG 7004918)South China University of Technology(National Key Research and Development Program of China,No.2016YFB0302000)Shenzhen University(Ten Thousand People’s Scheme,Project No.201,810,090,052)。
文摘With the prosperous development of artificial intelligence,medical diagnosis and electronic skins,wearable electronic devices have drawn much attention in our daily life.Flexible pressure sensors based on carbon materials with ultrahigh sensitivity,especially in a large pressure range regime are highly required in wearable applications.In this work,graphene membrane with a layer-by-layer structure has been successfully fabricated via a facile self-assembly and air-drying(SAAD)method.In the SAAD process,air-drying the self-assembled graphene hydrogels contributes to the uniform and compact layer structure in the obtained membranes.Owing to the excellent mechanical and electrical properties of graphene,the pressure sensor constructed by several layers of membranes exhibits high sensitivity(52.36 kPa……-1)and repeatability(short response and recovery time)in the loading pressure range of 0–50 kPa.Compared with most reported graphene-related pressure sensors,our device shows better sensitivity and wider applied pressure range.What’s more,we demonstrate it shows desired results in wearable applications for pulse monitoring,breathing detection as well as different intense motion recording such as walk,run and squat.It’s hoped that the facilely prepared layer-by-layer graphene membrane-based pressure sensors will have more potential to be used for smart wearable devices in the future.
基金the support of the National High Technology Research and Development Program of China (863) (Grant No. 2012AA1406)
文摘In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances in terms of data channel coding which might result in a signal structure where the symbol duration is shorter than the pseudo code period. This can generate some difficulties in the DSSS signal acquisition due to the polarity inversion caused by the data modulation. To eliminate the influence due to polarity inversion, this paper proposes a novel acquisition algorithm based on the simultaneous search of the code phase, data phase and Doppler frequency. In the proposed algorithm the data phase is predicted and the correlation period for the coherent integration can be set equal to the symbol duration. Then non-coherent accumulation over different symbol is implemented in order to enhance the acquisition algorithm sensitivity; the interval of non-coherent accumulation is the least common multiple between the symbol duration and the pseudo code period. The algorithm proposed can largely minimize the SNR loss caused by data polarity inversion and enhance acquisition performance without a noticeable increase in hardware complexity. Theoretical analysis, simulation and measured results verify the validity of the algorithm.
基金financial supports by the Shenzhen Science and Technology Project(No.JCYJ20180306172823786)the National Natural Science Foundation of China(Nos.21876141,NFFTBS-J1310024)。
文摘A dual emission sensing film has been prepared for colorimetric temperature sensing using CsPbBr_(3)perovskite nanocrystals(CsPbBr_(3)NCs)and manganese doped potassium fluorosilicate(K_(2)SiF_(6):Mn^(4+),KSF)encapsulated in polystyrene by a microencapsulation strategy.The CsPbBr_(3)-KSF-PS film shows good temperature sensing response from 30℃to 70℃,with a relative temperature sensitivity(Sr)up to 10.31%℃^(−1) at 45℃.Meanwhile,the film maintains more than 95%intensity after 6 heating-cooling cycles and keeps its fluorescence characteristics after 3 months.The film can be used to monitor temperature change by naked eye under a UV lamp.In particular,the temperature discoloration point of the sensing film can be controlled by the ratio change of CsPbBr_(3):KSF to expand its applications.The study of the CsPbBr_(3)-KSF-PS sensing mechanism in this work is helpful to provide effective strategies for the design of reliable,high sensitivity and stable temperature sensing system using CsPbBr_(3)NCs.
基金The project supported by the National Natural Science Foundation of China
文摘Based on geometric moire method, moire interferometry and microscopic moire interferometry, a high spatial resolution and high sensitivity geometric microscopic moire method is presented. Geometric micron-moire patterns are produced by the superposition of two high frequency gratings through a microscope system. Compared with other grating-based photo-mechanics methods, microscopic moire method could provide whole-field moire patterns of both high spatial resolution and high sensitivity. The frequency of specimen and reference gratings used in this method can be from 1 line/mm to 10000 lines/mm. Additionally, a 4F optical filter system is used to enhance the contrast of microscopic moire patterns effectively.
基金supported by the National Natural Science Foundation of China(No.51972341)the Shandong Natural Science Foundation,China(No.ZR2020MA069).
文摘Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the applications of flexible PSDs have been limited.Therefore,we presented a flexible broadband PSD based on a WS_(2)/Si heterostructure for the first time.A scalable sputtering method was used to deposit WS_(2)thin films onto the etched ultrathin crystalline Si surface.The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450-1350 nm,with a high position sensitivity of~539.8 mV·mm^(−1)and a fast response of 2.3μs,thanks to the strong light absorption,the built-in electrical field at the WS_(2)/Si interface,and facilitated transport.Furthermore,mechanical-bending tests revealed that after 200 mechanical-bending cycles,the WS_(2)/Si PSDs have excellent mechanical flexibility,stability,and durability,demonstrating the great potential in wearable PSDs with competitive performance.
基金funded by research organizations in Tunisia(Ministry of Public Health and Ministry of Higher Education and Scientific Research)。
文摘Background Coronary artery disease(CAD)remains a leading cause of morbidity and mortality.Cytokines play a potential role in atherosclerosis pathogenesis and progression.We investigated the association between high sensitive C-reactive protein(hs CRP)and severity of CAD.Methods CAD patients were stratified according to hs CRP cut-off value into high levels hs CRP group(≥8.4 mg/L)and low levels hs CRP group(<8.4 mg/L).Severity of CAD was assessed according to artery stenosis degree and the number of vessel involved.Statistical analysis was performed using Statistical Package for the Social Sciences(SPSS,version 23.0).Results The mean age was 60.3±11.0 years.The level of hs CRP was increased and ranged from 0.2 to 1020.0 mg/L.Biochemical risk factors and severity of CAD didn’t show significant differences between the two groups.In multivariate linear analysis,cardiac troponin I(c Tn I)and serum amyloid A(SAA)were predictors of hs CRP.As shown in receiver operating characteristic(ROC)curve analysis performed in patients with ST-segment elevation myocardial infarction(STEMI)and compared to myonecrosis biomarkers,hs CRP(area under the curve(AUC):0.905;95%CI:0.844-0.966;P<0.001)could be a powerful predictor marker in evaluating the infarct size after myocardial infarction but not better than c Tn I.Conclusions Hs CRP levels were not associated with the severity of CAD but could be useful in the evaluation of myocardial necrosis in patients with STEMI.
基金the National Natural Science Foundation of China(No.20876090)the Foundation for Research Initiation of Shaanxi University of Science&Technology(No.BJ09-15)Foundation for Innovative Research Team of Shaanxi University of Science&Technology(No.TD09-04)for financial support
文摘Structurally simple salicylaldehyde-based fluoreseent sensors for amino acids have been obtained by one-step or two-step synthesis.These sensors show significant fluorescence enhancement in the presence of many amino acids at concentrations as low as 10~5 mol/L.The reversible reaction of the aldehydes with amino acids to form imines in aqueous solution is proposed to account for the observed fluorescence enhancement.
文摘Biomarkers are early predictors of various disorders, circulating level of C-reactive protein is a sensitive biomarker of systemic inflammation and may also be associated with the development of diabetic, hepatic, and cardiovascular diseases. In the present study, we aimed to investigate the association between circulating levels of high sensitive C-reactive protein (hs-CRP) and various biomarkers for hepatic, diabetic, and cardiovascular health. The retrospective analysis included 438 individuals who were tested for these panels simultaneously at Vibrant America Clinical Laboratory. The study population included free-living individuals without any preexisting clinical conditions. Among the cardiovascular markers, a positive correlation and significant association was found between high levels of hs-CRP and serum levels of triglycerides (r = 0.0964, p −0.1423, p −0.1216, p < 0.0105) with circulating levels of hs-CRP. Among all the diabetic markers, glucose (r = 0.1547, p < 0.0011) and glycated serum protein (r = 0.1725, p < 0.0003) were positively correlated with circulating hs-CRP. In the hepatic panel, AST, a transaminase that plays a vital role in amino acid metabolism, was found to have a strong positive correlation with hs-CRP (r = 0.2139, p < 0.0001). In conclusion, the results clearly show the association of hs-CRP with diabetic, hepatic, and cardiovascular risk factors indicating its central value as a key marker for several lifestyle-associated disorders.
文摘High-sensitivity sensors represent a critical frontier in modern sensing technology,driving innovations across fields such as biomedical monitoring,precision instrumentation,environmental detection,and indus-trial automation.As demands for accuracy,miniaturization,and reliability continue to grow,developing novel sensor architectures and functional materials has become essential to achieving enhanced performance under extreme or complex conditions.
基金supported by the National Natural Science Foundation of China(Grant No.12302127)the Talents Introduction Project of Xihua University(Grant No.Z241008)the Key Project of Sichuan Province Modern Agricultural Equipment Engineering Technology Research Center(Grant No.XDNY2024-002).
文摘Respiratory rate monitoring is of great significance in pig healthy breeding for the early detection and timely prevention of respiratory diseases.Humidity sensing is an important noncontact method to monitor pig respiration,which does not cause direct harm to pigs and meets the requirements of animal welfare.This paper proposes a humidity sensor based on graphene oxide wrapped-silica microspheres(GO@SiO_(2)).First,the sensor shows fast response/recovery performances of 0.24/0.73 s.Experiments demonstrate that the wrapped microsphere structure can inhibit water aggregation.It is speculated that the wrapped microsphere structure can inhibit the stacking of GO,and its curved surface can promote the evaporation of water molecules.Second,the sensor shows a high sensitivity of 1.2%/%RH-4.2%/%RH in 11%-95%RH range.This can be attributed to different sensing mechanisms,from hopping transport to increasing ion transport,leading to a significant change in the sensor’s resistance.Third,the sensor shows selectivity to water molecules due to the hydrophilic characteristic of GO and the significant increase in conductivity by ion transport.Finally,the sensor is applied to realize the respiratory rate monitoring of adult pigs and piglets.
文摘Background The relationship between inflammatory markers and the characteristics of coronary atherosclerosis plaques is uncertain. The aim of the present study was to evaluate the relationship between the characteristics of coronary atherosclerosis plaques and inflammatory markers such as high sensitivity C-reactive proteins （Hs-CRP） and interleukin-6 （IL-6）. Methods All patients suspected of having coronary heart disease （CHD） underwent Siemens 64-slice CT angiography （64-SCTA） to distinguish the quality of plaque of coronary artery lesions. Blood samples were taken to measure levels of serum Hs-CRP and IL-6 in different plaque groups and the control group and compared with the value of 64-SCTA for detection of coronary artery plaque. Results The sensitivity of detecting coronary artery plaque by 64-SCTA was 87.4%, the specificity was 87.1%, the positive predictive value was 82.2%, and the negative predictive value was 91.0%. Comparing the levels of serum Hs-CRP and IL-6 among plaque groups, the mean levels of serum Hs-CRP and IL-6 in three plaque groups were significantly higher than those in the control group （P 〈0.01）. The mean levels of serum Hs-CRP and IL-6 in the soft plaque group and mixed plaque group were significantly higher than those in hard plaque group （P〈0.01）. Plaque burden in the soft plaque group and mixed plaque group was significantly higher than in the hard plaque group （P 〈0.01）, but there was no statistical difference between the soft plaque group and mixed plaque group （P=-0.246）. There was a negative correlation between the CT scale and Hs-CRP and IL-6 levels in the soft plaque group （r= -0.621, P〈0.01, and r= -0.593, P 〈0.01 respectively）. There was a positive correlation between the plaque burden and Hs-CRP and IL-6 levels in the soft plaque group （r=0.579, P〈0.05 and r=0.429, P〈0.05 respectively）. Conclusions 64-SCTA is an effective way to distinguish the different quality of coronary atherosclerosis plaque. Serum Hs-CRP and IL-6 levels can be considered as the indexes to judge the degree of CHD and may reflect the activity of plaque in CHD patients. Thus it is important for clinical diagnosis and risk evaluation of acute coronary syndrome （ACS） patients.
文摘Background Inflammation within vulnerable coronary plaques may cause unstable angina by promoting rupture and erosion. C-reactive protein （CRP） is the most reliable and accessible test method for clinical use for identifying coronary artery disease event. Matrix metalloproteinase 9 （MMP-9） is highly over-expressed in the vulnerable regions of a plaque. Our aim was to evaluate the plasma levels of MMP-9 and hsCRP in subjects with both unstable angina and coronary plaques, as well as in those with unstable angina without coronary plaques.
基金This work was supported by the National High Tech-nology Research and Development Program of China (No. 2005AA641010)the National Natural Science Foundation of China (No. 50534050).
文摘Tunable diode laser absorption spectroscopy （TDLAS） has been widely employed in atmospheric trace gases detection. In the measurement of these trace gases, harmonic detection combined with a multi-pass white cell could remarkably enhance the detection sensitivity. In this paper, a portable TDLAS system built specifically for long time monitoring methane in the atmosphere is introduced. The detection limit is below 100 ppb that is enough for the monitoring of ambient methane, and the long time monitoring results obtained in Beijing are given, which is well coincident with that of the Fourier transform infrared （FTIR） spectroscopy.
基金supported by the National Science Foundation,USA
文摘We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spectrocopy.The first method is employed to derive a metastasis lung tissue imaging at 3.7 THz with clear contrast between cancerous and healthy areas.The second approach is used to study an osseous tissue under several imaging modalities and achieve full THz spectroscopic imaging based on the frequency domain or on a fixed THz propagation time-delay.Sufficient contrast is achieved which facilitated the identification of regions with different cellular types and density compositions.
