A high sensitivity human chorionic gonado-tropin (hCG) detection was conducted by a tapered side-polished (TSP) optical fiber sensor. Experimentally, the TSP fiber sensor was made by side polishing a ...short section of single mode fiber to a D shape structure and tapering the D shape section to a small diameter (<inline-formula> <tex-math notation="LaTeX"> < 10~\mu \text{m} </tex-math></inline-formula> in the experiments). By functionalizing the primary antibody of hCG onto the TSP fiber surface, the sensor was used for detecting hCG concentration. Experimental results show that when the hCG concentration is 0.1 mIU/mL, the sensor has an average wavelength shift of 0.82 nm. The limit of detection (LoD) of the hCG is estimated 0.058 mIU/mL, assuming three times of maximum wavelength variation (<inline-formula> <tex-math notation="LaTeX">{3}\times {0}.{15}=0.45 </tex-math></inline-formula> nm) in Phosphate buffer saline (PBS) to the measurement limit. The specificity has also been tested by immersing the sensor into a mixed biomaterial solution (hCG - 1 mIU/mL, pig-IgG - 1 <inline-formula> <tex-math notation="LaTeX">\mu \text{g} </tex-math></inline-formula>/mL, Staphylococcus aureus <inline-formula> <tex-math notation="LaTeX">-{6}\times {10}^{{5}} </tex-math></inline-formula> CFU/mL and Escherichia coli - <inline-formula> <tex-math notation="LaTeX">{2.5}\times {10}^{{5}} </tex-math></inline-formula> CFU/mL). The result showed that the TSP optical fiber sensor has excellent specificity. The biosensor has potential application in clinical/medical diagnostics, human health, environmental quality and food safety monitoring.
Phase-sensitive optical time-domain reflectometer technology can transform the fiber-optic cable into a large-scale sensor array for distributed acoustic sensing (DAS), which is an emerging ...infrastructure for the Internet of Things. However, it is limitated in event recognition capability, which is a major factor preventing its practical field application. This article proposes a perturbation recognition algorithm based on GASF-ConvNeXt-TF with fast process and high recognition accuracy. First, Gramian angular summation field (GASF) algorithm is used to encode external disturbance signal to transform the 1-D time-series signal into a more concentrated 2-D image feature. Then the convolutional neural network model ConvNeXt_tiny network is applied as the classifier. In order to prevent the weight gradient from oscillating back and forth during network training process, a cosine annealing algorithm is introduced to control the decay of the learning rate. Meanwhile, transfer learning is used to further optimize the network model, resulting in higher classification accuracy and faster convergence. Finally, two different experimental scenarios are arranged in a total length of 2.2 km of optical fiber cable, and six different disturbance events (shaking, kicking, knocking, trampling, wheel rolling, and impacting) are set. Different from previous perimeter security disturbance identification experiments, not only single-point disturbance recognition is performed but also two points disturbances are simultaneously recognized, and all have good overall identification accuracy. The overall recognition accuracy of the six disturbance events in single and multiple points experiments are 99.3% and 98.3%, respectively, with an average recognition time of 0.103 s. The proposed technique has potential application in infrastructures structure health monitoring, such as factories, airports, energy pipeline, and highway.
The precipitation and dissolution behaviors of
δ
phase inside a deformed nickel-based superalloy during annealing treatment are investigated. A new method for quantitatively evaluating the content of
...δ
phase was proposed based on SEM micrograph, which was verified by X-ray diffraction (XRD) analysis. The effects of recrystallization during pre-annealing at 980 °C on the precipitation and dissolution behaviors of
δ
phase in the subsequent annealing treatment at 900 °C and 980 °C are discussed. Moreover, the improved precipitation and dissolution kinetics models are proposed to consider the effects of recrystallization fraction. The results show that: (1) for the precipitation of
δ
phase at 900 °C,
δ
phases precipitate first in grain boundaries and then within grains after a long incubation period. Moreover, the interval between adjacent
δ
phases increases first and then drops with the increasing recrystallization fraction during pre-annealing treatment. A balance between the precipitation and solution of
δ
phase at the aging temperature of 900 °C can be reached when the holding time is about 12 h; (2) for the dissolution of
δ
phase at 980 °C, the dissolution equilibrium can be obtained at approximate 200 min. Moreover, more rod-like
δ
phases can be remained with the increasing recrystallization fraction in pre-annealing treatment.
Stripe noise still remains in airborne short-wave infrared (SWIR) hyperspectral (HS) images after laboratory calibration due to the stray light of HS imager, nonlinear response of infrared focal ...plane array, and the distinct difference of equivalent color temperature between the integrating sphere and the sun. It is difficult to get a sun-like radiation source, and we apply the side-slither technique for relative radiometric correction of HS images. The calibration data corresponding to different irradiance were obtained by the side-slither technique of imager. Then, the two-point multi-section method is used for relative radiometric correction of HS images. This paper presents the principle, the experimental results, and the analysis of the proposed method. To validate the effectiveness of this method, it was compared with other methods and evaluated by quantitative quality indices. The results reveal that this method has a good performance in relative radiometric correction of HS image and is superior to the laboratory calibration based on integrating sphere. Consequently, the proposed method can successfully eliminate the adverse effect caused by the difference of equivalent color temperature between radiation sources, and also can improve the accuracy of HS applications such as absolute radiation correction and target recognition.
The effects of pre-treatments on the precipitate microstructures of an Al-Zn-Mg-Cu alloy are investigated. Meanwhile, the creep-rupture behavior of the under-aged and peak-aged alloys are ...comparatively analyzed. Additionally, the effects of pre-treatment on the fracture mechanisms are discussed. It is found that the precipitate microstructures are sensitive to pre-treatments. The intragranular precipitates of the peak-aged alloy are larger than those of the under-aged. The precipitate free zone of the peak-aged alloy is wider than that of the under-aged. Some large intergranular precipitates appear on the grain boundaries of the under-aged alloy, and induce the nucleation of microvoids. Eventually, the creep fracture of the under-aged alloy is accelerated. Therefore, the differences in microstructures lead to the shorter creep-rupture life of the under-aged alloy, compared to the peak-aged alloy.
Objective
To observe the efficacy of herbal cake-partitioned moxibustion for lumbar disc herniation (LDH) due to kidney deficiency and blood stasis and observe the influence of this method on lumbar ...functions and inflammatory factors in patients with this condition.
Methods
A total of 120 LDH patients who met the inclusion criteria were randomly divided into three groups, including a herbal cake-partitioned moxibustion group, a flour cake-partitioned moxibustion group, and a Western medication group, with 40 patients in each group. The patients in the Western medication group were treated with diflunisal tablets, 0.5 g per dose, 2 doses a day. Those in the herbal cake-partitioned moxibustion group were treated with additional herbal cake-partitioned moxibustion group at Back-Shu Points and Jiaji (EX-B2) Points once a day. Those in the flour cake-partitioned moxibustion group were treated with the same methods as in the herbal cake-partitioned moxibustion group, except that the herbal cake was replaced by a flour cake. All the patients were treated for 10 d. After treatment, the scores of the visual analog scale (VAS) and Japanese Orthopaedic Association (JOA) and the changes of the interleukin (IL)-6, tumor necrosis factor (TNF)-α, and substance P (SP) levels were observed, and the efficacy was evaluated.
Results
After treatment, the VAS score and the levels of IL-6, TNF-α, and SP were lower than those before treatment, and the JOA score was higher than that before treatment in the three groups, indicating intra-group statistical significance (
P
<0.05). The VAS score and the levels of IL-6, TNF-α, and SP of the herbal cake-partitioned moxibustion group were lower than those of the flour cake-partitioned moxibustion group and the Western medication group, while the JOA score of the herbal cake-partitioned moxibustion group was higher than that of the other two groups, indicating inter-group statistical significance (
P
<0.05). The total effective rate of the herbal cake-partitioned moxibustion group was 92.5%, higher than that of the flour cake-partitioned moxibustion group (80.0%) and the Western medication group (72.5%), indicating inter-group statistical significance (
P
<0.05).
Conclusion
On the basis of Western oral medication, additional herbal cake-partitioned moxibustion can alleviate the pain and improve the lumbar functions in patients with LDH due to kidney deficiency and blood stasis. The efficacy of the integrated method is better than that of either flour cake-partitioned moxibustion or Western medication alone, which may be related to the reduction of serum inflammatory factors.
Spontaneous firing of ventral tegmental area (VTA) dopamine (DA) neurons provides ambient levels of DA in target areas such as the nucleus accumbens (NAc) and the prefrontal cortex (PFC). Here we ...report that the glial cell line-derived neurotrophic factor (GDNF), produced in one target region, the NAc, is retrogradely transported by DA neurons to the VTA where the growth factor positively regulates the spontaneous firing activity of both NAc- and PFC-projecting DA neurons in a mechanism that requires the activation of the mitogen-activated protein kinase (MAPK) pathway. We also show that the consequence of GDNF-mediated activation of the MAPK signaling cascade in the VTA is an increase in DA overflow in the NAc. Together, these results demonstrate that NAc-produced GDNF serves as a retrograde enhancer that upregulates the activity of the mesocorticolimbic DA system.
A challenge for optical fiber biosensor is to achieve ultrahigh sensitivity with narrow full width at half maximum (FWHM) of the spectrum. To address this challenge, an ultrahigh-sensitivity ...microfiber interferometer fiber ring laser (FRL) biosensor is proposed and investigated for Listeria monocytogenes (L. monocytogenes) detection. The fiber biosensor is composed of a singlemode- tapered no core-singlemode (STNS) fiber configuration, which is functionalized with the anti-L. monocytogenes antibodies. An Erbium Doped Fiber Amplifier is applied to the sensor to excite laser and thus reduce the FWHM of the spectrum, which significantly improved the limit of detection (LoD). The proposed STNS FRL biosensor has excellent reproducibility, specificity and sensitivity for L. monocytogenes. The developed STNS FRL biosensor can directly detect L. monocytogenes cells with LoD as low as 1.0 cell/mL, indicating the capability for detecting single cell of L. monocytogenes. Real lettuce and milk samples have been tested and test result in lettuce and milk samples has deviations within ± 30 % from that of Phosphate-buffered saline (PBS) for L. monocytogenes concentrations vary from 101 to 103 cells/mL(g). The developed STNS FRL biosensor has ultrahigh sensitivity, good stability, reproducibility, and specificity, which has potential applications in diseases/medical diagnostics.
•Developed new STNS fiber ring laser configuration capable detecting 1.0 cell/mL Listeria monocytogenes solution.•Provide very narrow FWHM of 0.15 nm due to the introduction of fiber ring laser configuration.•Demonstrated detecting 10 cells/ml Listeria monocytogenes in complex food matrices of real milk and lettuce samples.•The sensor structure has potential for medical diagnostics and food safety inspection.
•Present a new polymer-based (Locatite3525) microbottle resonator fabricated by UV light irradiation and thermal reflow technology.•By optimizing the concentration of the dip impregnation GO ...solution, the microbottle resonator exhibited high RH sensitivity and figure of merit of 0.161 nm/%RH and 2.01/%RH.•After high-temperature annealing at 300 °C, temperature sensitivity of the microbottle resonator decreased by an order of magnitude, which significantly reduces the cross-sensitivity between humidity and temperature.
A polymer-based micro-bottle resonator coated with graphene oxide (GO) film is presented to improve the relative humidity (RH) sensing performance. Polymeric material Loctite 3525 was coated onto a quartz fiber and cured by using UV light irradiation and thermal reflow technology. A layer of GO film was prepared on the micro-bottle resonator by the dip impregnation method, which realized a high Q-factor (>104) transmission of energy by appropriately designing a wave-guide resonator coupling. By optimizing the concentration of GO dip impregnation solution, high sensitivity and figure of merit (FoM) of 0.161 nm/%RH and 2.01/%RH were achieved in the RH range of 22–81%. In addition, after high-temperature annealing at 300 °C, the temperature sensitivity decreased by an order of magnitude from 0.793 nm/°C to 0.068 nm/°C, which significantly reduces the cross-sensitivity between humidity and temperature. The proposed resonator has the advantages of being compact in size, low in cost, high sensitivity, and low in temperature crosstalk.
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