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Limited by the narrow enhanced area of nanoscale on the metal surface, the sensitivity of surface-enhanced Raman spectroscopy (SERS) detection in solution is usually much lower than the detection in a solid substrate, which is dramatic in microfluidics for online detection. In this work, a cellulose microfilament embraced by Ag nanoparticles, called plasmonic cellulose microfilament, is located in a microchannel for SERS detection in microfluidics. Benefiting from the congestion caused by the plasmonic cellulose microfilament in a microchannel, the trace molecule in the solution is much easier to gather in Ag nanoparticles for Raman enhancement. To obtain high sensitivity, the structure of plasmonic cellulose microfilament is optimized. The SERS spectra collected in this novel microfluidics demonstrate that the plasmonic cellulose microfilament presents a high sensitivity at 10-13 M and good reproducibility in SERS detection. In addition, automatic identification of urea presence or absence was achieved based on deep learning (DL) here. The results show excellent diagnostic accuracy (99 %), which suggests that a fast, label-free urea screening tool can be developed. These results point out this SERS microfluidics with plasmonic cellulose microfilament has a great application prospective in online SERS detection with high sensitivity.

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Objective: This study aimed to investigate the potential plasma miRNA-mRNA regulatory networks in postmenopausal women with osteoporosis (OP) and osteoporotic vertebral fracture (OVF). Methods: The study employed a cross-sectional design, and the microarray dataset GSE93883 was acquired from the Gene Expression Omnibus (GEO) to assess plasma miRNA profiles in postmenopausal women with osteoporosis (OP) and osteoporotic vertebral fracture (OVF). Subsequently, plasma microRNA-4739 (miR-4739) and Insulin-like Growth Factor Binding Protein-4 (IGFBP-4) levels were validated in a well-defined cohort comprising 210 postmenopausal women. This cohort consisted of three distinct groups: healthy controls (HC, n = 70), OP patients (n = 70), and OVF patients (n = 70). Results: Analysis of the GSE93883 dataset revealed a stepwise increase in four miRNAs (hsa-miR-4739, hsa-miR-4505, hsa-miR-4459, hsa-miR-665) in plasma samples from HC to OP patients to OVF patients. Conversely, plasma miR-4666a-3p showed a gradual decrease. We predicted six genes targeted by miR-4739 using six online databases. Plasma miR-4739 levels were significantly higher in OP and OVF patients compared to HC, especially in OVF patients. However, plasma IGFBP-4 exhibited an inverse pattern. Pearson analysis demonstrated a significant negative correlation between plasma miR-4739 and plasma IGFBP-4 in OP and OVF patients. Receiver operating characteristic (ROC) curve analysis of plasma miR-4739 yielded a sensitivity of 35.71% and specificity of 95.71% for predicting the presence of OP and a sensitivity of 71.43% and specificity of 95.71% for predicting OVF, with an AUC of 0.865. Moreover, the area under the curve (AUC) for IGFBP-4 was higher than that for plasma miR-4739 when differentiating OP patients from OVF patients. Conclusions: Circulating miR-4739 and IGFBP-4 demonstrated a negative correlation in OP and OVF patients, suggesting their potential as diagnostic biomarkers for OP and OVF in the future.

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The surface spectral reflectance of an object is the key factor for high-fidelity color reproduction and material analysis, and spectral acquisition is the basis of its applications. Based on the theoretical imaging model of a digital camera, the spectral reflectance of any pixels in the image can be obtained through spectral reconstruction technology. This technology can avoid the application limitations of spectral cameras in open scenarios and obtain high spatial resolution multispectral images. However, the current spectral reconstruction algorithms are sensitive to the exposure variant of the test images. That is, when the exposure of the test image is different from that of the training image, the reconstructed spectral curve of the test object will deviate from the real spectral to varying degrees, which will lead to the spectral data of the target object being accurately reconstructed. This article proposes an optimized method for spectral reconstruction based on data augmentation and attention mechanisms using the current deep learning-based spectral reconstruction framework. The proposed method is exposure invariant and will adapt to the open environment in which the light is easily changed and the illumination is non-uniform. Thus, the robustness and reconstruction accuracy of the spectral reconstruction model in practical applications are improved. The experiments show that the proposed method can accurately reconstruct the shape of the spectral reflectance curve of the test object under different test exposure levels. And the spectral reconstruction error of our method at different exposure levels is significantly lower than that of the existing methods, which verifies the proposed method's effectiveness and superiority.

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High-precision segmentation of ancient mural images is the foundation of their digital virtual restoration. However, the complexity of the color appearance of ancient murals makes it difficult to achieve high-precision segmentation when using traditional algorithms directly. To address the current challenges in ancient mural image segmentation, an optimized method based on a superpixel algorithm is proposed in this study. First, the simple linear iterative clustering (SLIC) algorithm is applied to the input mural images to obtain superpixels. Then, the density-based spatial clustering of applications with noise (DBSCAN) algorithm is used to cluster the superpixels to obtain the initial clustered images. Subsequently, a series of optimized strategies, including (1) merging the small noise superpixels, (2) segmenting and merging the large noise superpixels, (3) merging initial clusters based on color similarity and positional adjacency to obtain the merged regions, and (4) segmenting and merging the color-mixing noisy superpixels in each of the merged regions, are applied to the initial cluster images sequentially. Finally, the optimized segmentation results are obtained. The proposed method is tested and compared with existing methods based on simulated and real mural images. The results show that the proposed method is effective and outperforms the existing methods.

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Electrorheological (ER) fluid, containing polarized particles within an insulating liquid, represents a smart material, the mechanical properties of which can be altered mainly by an electric field. In this work, ER fluids based on cauliflower iron(ii) oxalate doped titanium particles show excellent rheological and wetting properties by the sample co-precipitation method. The morphology of the particles is observed by SEM and the molecular structure within the particles is obtained via XRD and FTIR. The distribution of elements within the particles is obtained by EDS. Owing to a lower current density than pure iron(ii) oxalate, the SEM and optical images show an obvious chain-like structure within the ER fluids with 2 wt% and 5 wt%, respectively, under 2 kV mm-1. Then, the rheological properties of these ER fluids are tested up to 3 kV mm-1 and the results show a gratifying property of resisting shear with different shear rates (0.1-100 s-1), which is attributed to the appearance of a stable chain-like structure. At the same time, the ER efficiency and the switching performance are obtained and the static yield stress fits the relevant electric field strength well. Ultimately, an excellent sedimentation ratio is obtained from 0 h to 600 h.

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Combined with microfluidics, surface-enhanced Raman spectroscopy (SERS) exhibits huge application prospective in sensitive online detection. In current studies, the design and optimization of plasmonic enhanced structures in microfluidics for SERS detection could be an interesting challenge. In this work, hybrid plasmonic 2D microplates composed of Mxenes (Ti3C2Tx) microplates and in-situ synthesized Au nanoparticles (Au NPs) are fabricated in a microchannel for enhanced structures in SERS microfluidics. Benefiting from the 2D Mxenes microplates with complex distributions, the enhanced areas generated by Au NPs are quite enlarged in a microchannel, which exhibits high sensitivity in SERS detection at 10-10 M for Nile blue (NB) molecules in microfluidics. The mechanism of electromagnetic enhancement (EM) and chemical enhancement (CM) is analyzed. The experimental data indicate the ultrasonic times of Mxenes and the concentration of Au3+ play important roles in the sensitivity of SERS detection, which is confirmed by the simulated electric field distributions. Furthermore, a typical pesticide (thiram) at 100 ppm in water is detected on these SERS microfluidics with hybrid plasmonic enhanced structures, which demonstrates that our work not only strengthens the knowledge of plasmonics but also enlarges the application of SERS.

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The combination of photonic and plasmonic elements with complementary optical properties has stimulated the development of optoplasmonic hybrid systems, in which photonic and plasmonic elements can interact synergistically, breaking through the limitations of traditional structures. In this paper, a new optoplasmonic tweezer is theoretically proposed by using the Au nanobowtie and SiO2 microsphere. The finite-difference time-domain simulation is used to study the influence of the size of the SiO2 microsphere and the SiO2 hemisphere in polydimethylsiloxane on the optical potential well. The simulation results show that the electric field intensity of the structure is increased by 6 times compared with the Au nanobowtie structure, and the gradient force and the trapping potential are also significantly improved.

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Combining both localized surface plasmon polaritons (LSPPs) and propagating surface plasmon polaritons, remote surface-enhanced Raman scattering (SERS) emerges as a novel sensing technology in recent years, which could avoid the overlap of incident light and inelastic scattering light in SERS. Compared to traditional SERS, it has novel applications in sensors, plasmon-driven surface-catalyzed reactions, Raman optical activity, etc. However, the weak Raman intensity of remote SERS impedes its further application. In this work, we demonstrated that the remote SERS signals could be enhanced by more than 100% through the subwavelength interference in dual-path-excited Ag-branched nanowire dimer and nanowire-nanoparticle systems. Our experiment has revealed that remote SERS intensities could be modulated by polarization and phase differences of two incident lights illuminating at two separate nanowire terminals. The simulated electromagnetic field distributions through the finite-difference time-domain (FDTD) method indicate that subwavelength interference occurs in Ag nanowires, which causes the Raman intensities collected at a remote site is greatly influenced by the coherent superposition of propagating surface plasmon polaritons (PSPPs). Our work on this coherent enhancement could not only promote the application of remote SERS but also enlarge the research on light manipulating in the subwavelength.

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Sensitive in situ detection of organic molecules is highly demanded in environmental monitoring. In this work, the surface enhanced Raman spectroscopy (SERS) is adopted in microfluidics to detect the organic molecules with high accuracy and high sensitivity. Here the SERS substrate in microchannel consists of Ag nanoparticles synthesized by chemical reduction. The data indicates the fabrication conditions have great influence on the sizes and distributions of Ag nanoparticles, which play an important role on the SERS enhancement. This result is further confirmed by the simulation of electromagnetic field distributions based on finite difference time domain (FDTD) method. Furthermore, the SERS spectra of organic molecule (methylene blue) obtained in this plasmonic microfluidic system exhibit good reproducibility with high sensitivity. By a combination of SERS and microfluidics, our work not only explores the research field of plasmonics but also has broad application prospects in environmental monitoring.

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OBJECTIVE: To discuss the clinical significance of antibacterial peptide LL-37 in the early diagnosis of patients with sepsis in emergency department. METHODS: Forty patients diagnosed with sepsis in the emergency department of the Affiliated Hospital of Zunyi Medical College from December 2017 to March 2018 were enrolled as sepsis group. Twenty healthy volunteers were enrolled contemporaneously in our hospital at medical center as healthy control group. Peripheral blood was collected immediately after diagnosis in sepsis group or during physical examination in healthy control group. The expression of antibacterial peptide LL-37 was determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile, serum procalcitonin (PCT) and C-reactive protein (CRP) levels were determined. The differences in antibacterial peptide LL-37, PCT and CRP levels between the two groups were compared. Pearson correlation method was used to analyze the correlation between antibacterial peptide LL-37, PCT and CRP. Receiver operating characteristic (ROC) curve was drawn, and the early individually or jointly diagnostic value of each detected index for sepsis was analyzed. RESULTS: The levels of antimicrobial peptide LL-37, PCT and CRP in peripheral blood of sepsis group were significantly higher than those of healthy control group [LL-37 (µg/L): 1.34±0.69 vs. 0.10±0.06, PCT (µg/L): 46.67±39.51 vs. 0.03±0.02, CRP (mg/L): 129.68±49.83 vs. 3.16±2.85], with statistically significant differences (all P < 0.05). Pearson correlation analysis showed that the expression of antimicrobial peptide LL-37 was positively correlated with PCT and CRP levels (r1 = 0.835, r2 = 0.932, both P < 0.01). ROC curve analysis showed that the area under ROC curve (AUC) of LL-37, PCT and CRP for early diagnosis of sepsis was 0.885, 0.963 and 0.983, respectively, and the AUC of combined diagnosis of the three parameters was as high as 0.994, indicating that the value of combined diagnosis of sepsis was greater than that of single diagnosis; when the combined prediction probability of the three parameters was 0.92, the sensitivity was 97.5%, and the specificity was 95.0%. CONCLUSIONS: Antibacterial peptide LL-37 has certain clinical value in early diagnosis of patients with sepsis, which can be used as early routine monitoring indicators for patients with early sepsis when combined with PCT and CRP.

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On-chip fabrication of surface-enhanced Raman spectroscopy (SERS)-active materials enables continuous, real-time sensing of targets in the microfluidic chip. However, the current techniques require the time-consuming, complicated process and costly, bulky facilities. In this work, we present a novel method for synthesis of Ag nanostructures in a microfluidic channel via one-step electroless galvanic replacement reaction. The whole reaction could be achieved <10 mins, while the traditional methods take hours. The microfluidic channel has a Cu base, which can reduce Ag ions to Ag nanoparticles in the presence of AgNO3 solution. The new technique enables the label-free sensing of chemical molecules (i.e., methylene blue) and biomolecules (i.e., urea). Two proof-of-concept experiments are performed to verify the utilization of the prepared SERS substrate. First, the microfluidics-assisted SERS sensor is used to detect Hg ions in aqueous solution with high sensitivity and good selectivity. Second, the fabricated SERS-active material can couple with a concentration gradient generator for continuous SERS detection. This simple technique can be used in any laboratory without any bulky equipment and can realize numerous lab-on-a-chip applications with the integration of other microfluidic networks.

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OBJECTIVE: The etiology of hemophagocytic lymphohistiocytosis (HLH) is complicated and difficult to diagnose, unexplained HLH often with hematological malignancies. Invasive biopsy can help to find etiology, the results may be affected by the technique and the location of the puncture site. Multiangle puncture can improve the success rate, but the corresponding risk increases. A patient with HLH was admitted to Affiliated Hospital of Zunyi Medical College. The etiology was unknown. Active symptomatic support treatment was conducted, at the same time, finding the evidence of viral infection, autoimmune disease related detection, blood culture, bone marrow puncture smear and spleen biopsy were performed respectively to find the pathogen basis. Spleen hemorrhage was not being controlled after spleen biopsy in patients, and emergency splenectomy was adopted to stop bleeding for saving lives. Finally, the patients died of low protein, pulmonary edema and respiratory failure. The bone marrow puncture and spleen biopsy failed to provide the basis for tumor invasion, while the spleen pathological slices plus immunohistochemical indicate diffuse large B cell lymphoma (DLBCL) after splenectomy, which was identified as malignant tumor-associated hemophagocytic syndrome. Underscoring the high risk of bleeding after tumor-associated splenomegaly puncture and the importance of having emergency plans. Through analyzing the clinical characteristics, diagnosis and treatment of this patient, we hope to improve the clinicians' understanding of HLH and lymphoma.

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With high sensitivity at single molecule level, surface-enhanced Raman scattering (SERS) is considered as an ultrasensitive optical detection technology with broad application prospects in lots of fields. However, the complicated fabrication and unaffordable price of SERS substrate are still a roadblock on the way to be widely used in industry. In this work, the SERS spectra on a commercial laser engraved Teflon (PTFE) film with engraved microarray are investigated. The wettability of film surface modulated by laser engraving make the microarray have the ability to decrease the contact area on film surface while water evaporation. The SEM image of the engraved area points out the micro/nanostructures generated engraving process is crucial to its superhydrophobic property. The probing molecules (i.e., methylene blue and rhodamine6G) were utilized to investigate with the limit of detection (1 × 10-14 M). Furthermore, the biomolecule (bovine serum albumin) was used to demonstrate its benefits in biological applications. The measured intensities of Raman spectra on this PTFE with laser engraved microarray demonstrate its potential value for a SERS substrate. Our work on this simple, cheap SERS substrate with high sensitivity has a great commercial value and plenty of application in lots of fields.

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In this paper, we propose new sufficient criteria for input-to-state stability (ISS) of time-varying nonlinear discrete-time systems via indefinite difference Lyapunov functions. The proposed sufficient conditions for ISS of system are more relaxed than for ISS with respect to Lyapunov functions with negative definite difference. We prove system is ISS by two methods. The first way is to prove system is ISS by indefinite difference ISS Lyapunov functions. The second method is to prove system is ISS via introducing an auxiliary system and indefinite difference robust Lyapunov functions. The comparison of the sufficient conditions for ISS obtained via the two methods is discussed. The effectiveness of our results is illustrated by three numerical examples.

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Benefiting from the induced image charge on metal film, the light energy is confined on a film surface under metal nanoparticle dimer, which is called electromagnetic field redistribution. In this work, electromagnetic field distribution of metal nanoparticle monomer or dimer on graphene is investigated through finite-difference time-domain method. The results point out that the electromagnetic field (EM) redistribution occurs in this nanoparticle/graphene hybrid system at infrared region where light energy could also be confined on a monolayer graphene surface. Surface charge distribution was analyzed using finite element analysis, and surface-enhanced Raman spectrum (SERS) was utilized to verify this phenomenon. Furthermore, the data about dielectric nanoparticle on monolayer graphene demonstrate this EM redistribution is attributed to strong coupling between light-excited surface charge on monolayer graphene and graphene plasmon-induced image charge on dielectric nanoparticle surface. Our work extends the knowledge of monolayer graphene plasmon, which has a wide range of applications in monolayer graphene-related film.

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The properties of silver nanowire (AgNW) films in the optical and infrared spectral regime offer an interesting opportunity for a broad range of applications that require low-emissivity coatings. This work reports a method to reduce the thermal emissivity of substrates by the formation of low-emissivity AgNW coating films from solution. The spectral emissivity was characterized by thermal imaging with an FLIR camera, followed by Fourier transform infrared spectroscopy. In a combined experimental and simulation study, we provide fundamental data of the transmittance, reflectance, haze, and emissivity of AgNW thin films. Emissivity values were finely tuned by modifying the concentration of the metal nanowires in the films. The simulation models based on the transfer matrix method developed for the AgNW thin films provided optical values that show a good agreement with the measurements.

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Hollow noble metal nanoparticles have excellent performance not only in surface catalysis but also in optics. In this work, the hollow Au-Ag alloy nanorices are fabricated by the galvanic replacement reaction. The dark-field spectrum points out that there is a big difference in the optical properties between the pure Ag nanorices and the hollow alloy nanorices that exhibit highly tunable localized surface plasmon resonances (LSPR) and that possess larger radiative damping, which is also indicated by the finite element method. Furthermore, the surface enhanced Raman scattering (SERS) and oxidation test indicate that hollow Au-Ag alloy nanorices show good anti-oxidation and have broad application prospects in surface-plasmon-related fields.

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High thermal conductivity of CoSbS-based limited its own prospect application in thermoelectric energy conversion. Solid solution is an effective approach to optimize the performance of thermoelectric materials with high lattice thermal conductivity because of the enhanced phonons scattering from disorder atoms. In this paper, we have synthesized and measured the thermoelectric properties of solid solution CoSbS1-xSex (x = 0, 0.05, 0.10, 0.15, 0.20, 0.30) series samples. The collaborative optimization (enhancing the power factors and reducing the thermal conductivities) to add zT values were realized via substitution of S atoms with the isoelectronic Se atoms in the matrix. Meanwhile, the lowest room temperature lattice thermal conductivity in CoSbS-based materials is obtained (4.72 W m-1 K-1) at present. Benefiting from the results of synergistic strategy, a zT of 0.35 was achieved at 923 K for sample CoSbS0.85Se0.15, a 59% improvement as compared with that of the pristine CoSbS. Band calculation demonstrated that CoSbS0.85Se0.15 present a similar band dispersion with CoSbS. The mechanism of point defect scattering for reducing the lattice thermal conductivity at room temperature, was also analyzed by the Callaway model. The contributions to decrease the room temperature lattice thermal conductivity from the mass and the strain fluctuation in the crystal are comparable. These results can also be extended to other high-efficiency thermoelectric materials with stiff bond and smaller Gruneisen parameters.

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For the virtues of convenience and repeatability, photochemically deposited nanoparticles (NPs) as ferroelectric-based surface-enhanced Raman scattering (SERS) substrates have great potential in the surface-plasmon-related applications. In this work, the plasmon-driven surface catalysis (PDSC) reaction is investigated on lithium niobate (LiNbO3) film with photochemically deposited Au NPs. The SERS spectra indicate that the performance of PDSC reaction on a substrate with various Au3+ concentrations in photochemical deposition is obviously different. Combining structure characterization and electromagnetic field simulation, this result is mainly attributed to the surface plasmon coupling between Au NPs. Furthermore, the results also point out that the exposure time in photochemical deposition plays an important role in PDSC reactions. Our studies on photochemically deposited Au NP substrates provide strong support and further understanding to the research on PDSC reactions and also to other surface-plasmon-related fields.

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Exploring the novel shape of Pt nanoparticles is one of the most useful ways to improve the electrocatalytic performance of Pt in fuel cells. In this work, the Pt nanopeanuts consisting of two nanospheres grown together have been fabricated through a two-step polyol method. The high resolution scanning electron microscope (SEM) images and energy dispersive x-ray (EDX) spectrum collected at adjacent part point out the Pt nanopeanut is apparently different from the two physical attached nanospheres. To understand the growth mechanism of this nanopeanut, the final products in different synthesis situations are studied. The results indicate the interesting morphology of Pt nanopeanuts mainly benefit from the chemical reagent (FeCl3) while the size and homogeneity are greatly affected by the temperature. Furthermore, the electrocatalytic activity of the Pt nanopeanuts has also been demonstrated here. Our two-step synthesis of Pt nanopeanuts not only enlarges the group of Pt nanoparticles, but also provides a beneficial strategy for the synthesis of novel metal nanoparticles.