Automatic Suppression Method for Water Surface Glints Using a Division of Focal Plane Visible Polarimeter.

To address the problem of water surface detection imaging equipment being susceptible to water surface glints, this study demonstrates a method called De-Glints for suppressing glints and obtaining clear underwater images using a division of focal plane (DoFP) polarimeter. Based on the principle of polarization imaging, the best polarization angle and the image corresponding to the minimal average gray level of each pixel are calculated. To evaluate the improvement in image quality, the index E was designed. The results of indoor and outdoor experiments show that the error of the angle calculation of this method is within 10%, and the minimum error is only 3%. The E index is positively improved and can be relatively improved by 8.00 under the interference of strong outdoor glints, and the method proposed in this paper shows a good adaptive ability to the dynamic scene.

Baseline correction for Raman spectra using a spectral estimation-based asymmetrically reweighted penalized least squares method.

Baseline correction is necessary for the qualitative and quantitative analysis of samples because of the existence of background fluorescence interference in Raman spectra. The asymmetric least squares (ALS) method is an adaptive and automated algorithm that avoids peak detection operations along with other user interactions. However, current ALS-based improved algorithms only consider the smoothness configuration of regions where the signals are greater than the fitted baseline, which results in smoothing distortion. In this paper, an asymmetrically reweighted penalized least squares method based on spectral estimation (SEALS) is proposed. SEALS considers not only the uniform distribution of additive noise along the baseline but also the energy distribution of the signal above and below the fitted baseline. The energy distribution is estimated using inverse Fourier and autoregressive models to create a spectral estimation kernel. This kernel effectively optimizes and balances the asymmetric weight assigned to each data point. By doing so, it resolves the issue of local oversmoothing that is typically encountered in the asymmetrically reweighted penalized least squares method. This oversmoothing problem can negatively impact the iteration depth and accuracy of baseline fitting. In comparative experiments on simulated spectra, SEALS demonstrated a better baseline fitting performance compared to several other advanced baseline correction methods, both under moderate and strong fluorescence backgrounds. It has also been proven to be highly resistant to noise interference. When applied to real Raman spectra, the algorithm correctly restored the weak peaks and removed the fluorescence peaks, demonstrating the effectiveness of this method. The computation time of the proposed method was approximately 0.05 s, which satisfies the real-time baseline correction requirements of practical spectroscopy acquisition.

Self-calibration algorithm for installation angle deviation of bionic polarization compound eyes.

A self-calibration algorithm based on unsupervised optimization for polarizer installation angle deviation is proposed and used in a multi-aperture bionic polarization compound eye system. To simplify calibration operation, under the condition that the calibration-polarized light information is unknown, this algorithm fully exploits redundancy and random polarization information in the scene, and uses a non-convex multi-objective discrete parameter sorting optimization method to achieve angle self-calibration. Compared with ordinary calibration procedures, the algorithm requires less stringent conditions, achieves online calibration and is more accurate. It also can be applied to camera polarization arrays, division-of-focal-plane polarization cameras, and other polarization devices.

High-Speed Rail Tunnel Panoramic Inspection Image Recognition Technology Based on Improved YOLOv5.

In order to meet the fast and accurate automatic detection requirements of equipment maintenance in railway tunnels in the era of high-speed railways, as well as adapting to the high dynamic, low-illumination imaging environment formed by strong light at the tunnel exit, we propose an automatic inspection solution based on panoramic imaging and object recognition with deep learning. We installed a hyperboloid catadioptric panoramic imaging system on an inspection vehicle to obtain a large field of view as well as to shield the high dynamic phenomena at the tunnel exit, and proposed a YOLOv5-CCFE object detection model based on railway equipment recognition. The experimental results show that the mAP@0.5 value of the YOLOv5-CCFE model reaches 98.6%, and mAP@0.5:0.95 reaches 68.9%. The FPS value is 158, which can meet the automatic inspection requirements of railway tunnel equipment along the line and has high practical application value.

Impact of Radiotherapy Combined With Chemotherapy on Long-Term Outcomes of Patients With Recurrent Nasopharyngeal Carcinoma.

Background: It remains controversial whether the application of chemotherapy has an impact on recurrent nasopharyngeal carcinoma (rNPC) patients with salvage radiotherapy. Here, we aimed to evaluate treatment outcomes of rNPC patients and derive a prognostic model to assess the benefit of chemotherapy in patients with re-radiotherapy. Methods: This study was conducted as a retrospective study. In total, 340 rNPC patients treated with salvage intensity-modulated radiotherapy (IMRT) or radiochemotherapy (RCT) from October 2006 to September 2019 were included in this study. Overall survival (OS) was the primary outcome. Kaplan-Meier method was employed to detect the prognostic difference with Log-rank tests. The Cox regression analysis was performed to explore the potential prognostic factors while the multivariate Cox analysis was used to identify candidate variables for the prognostic model of OS. Results: The 5-year actuarial rates of OS, progression-free survival, loco-regional progression-free survival, and distant metastases-free survival did not show significant difference between the IMRT and RCT groups (P > .05). Age at recurrence and rT category were found to be the independent prognostic factors for OS. We found that rNPC patients suffered poor OS in the high-risk group (patients with higher age at recurrence and advanced rT category) (high-risk vs low-risk, HR = 1.87, 95% CI: 1.36-2.57, P < .001). Salvage RT alone may be superior to RCT for patients in the low-risk group (RCT group vs RT group, HR = 1.89, 95% CI: 1.11-3.20, P = .038). Conclusion: Salvage RT combined with chemotherapy cannot improve survival outcomes for rNPC. More novel clinical trials should be explored to develop individualized strategies to improve survival and minimize toxicities.

Revisiting the nexus between fiscal decentralization and environment: evidence from fiscally decentralized economies.

Fiscal decentralization is a topic of great importance, especially in the context of environmental sustainability. Numerous research studies have been conducted on fiscal decentralization providing conflicting results, and therefore, the current study fills the gap by examining the effect of fiscal decentralization on environmental quality in the presence of environment-related technological innovation, renewable energy consumption, international trade, and economic growth taking seven fiscally decentralized advanced OECD countries as a case study. Using data from 1990 to 2018, we employed the Spatial Durbin Model (SDM) to test the spatial spillover effect of fiscal decentralization on the environment in seven fiscally decentralized countries. The primary findings show that carbon emissions are affected by the associated regions, which significantly correlates with the spatial distribution, and in the short run, fiscal decentralization increases carbon emissions. However, in the long run, fiscal decentralization decreases carbon emissions and is essential for achieving the goals of net-zero carbon emission. The results also show that the indirect effect is significantly positive in the economic-geographical weight matrix, and the spatial spillover effect of fiscal decentralization is not conducive to the environment of countries with economic exchanges. Furthermore, fiscal decentralization has a threshold effect, and the results show that when the fiscal decentralization degree is higher, it significantly reduces CO2 emissions. Any policy in these countries that target renewable energy, fiscal decentralization, and eco-innovation will significantly reduce carbon emissions.

Residual Interpolation Integrated Pixel-by-Pixel Adaptive Iterative Process for Division of Focal Plane Polarimeters.

Residual interpolations are effective methods to reduce the instantaneous field-of-view error of division of focal plane (DoFP) polarimeters. However, their guide-image selection strategies are improper, and do not consider the DoFP polarimeters' spatial sampling modes. Thus, we propose a residual interpolation method with a new guide-image selection strategy based on the spatial layout of the pixeled polarizer array to improve the sampling rate of the guide image. The interpolation performance is also improved by the proposed pixel-by-pixel, adaptive iterative process and the weighted average fusion of the results of the minimized residual and minimized Laplacian energy guide filters. Visual and objective evaluations demonstrate the proposed method's superiority to the existing state-of-the-art methods. The proposed method proves that considering the spatial layout of the pixeled polarizer array on the physical level is vital to improving the performance of interpolation methods for DoFP polarimeters.

Temporal and spatial error model for estimating the measurement precision of the division of focal plane polarimeters.

Temporal noise and spatial non-uniformity primarily limit the measurement precision of division of focal plane (DoFP) polarimeters, based on which this study proposes an error model for DoFP polarimeters. The closed-form expressions of the estimation error of the main polarization parameters (Stokes vector, degree of linear polarization, and angle of linear polarization) are derived. Compared with the existing error models for DoFP polarimeters in the presence of temporal noise, the proposed model modifies the normalization condition in traditional calibration methods of DoFP polarimeters and clarifies the selection rule of the coefficient matrix leading to more accurate precision estimation; and experiments using linearly polarized light on a real-world DoFP polarimeter prove its validity.

Can Health Human Capital Help the Sub-Saharan Africa Out of the Poverty Trap? An ARDL Model Approach.

This article explores the impact of health human capital on the poverty trap in Sub-Saharan Africa by autoregressive distribution lag model. In the long run, there is no evidence that health human capital can help the Sahara out of the poverty trap. While health human capital has a significant effect on poverty reduction in the short term. There is a threshold effect in the poverty reduction model of healthy human capital. When the economic development level reaches the threshold, the effect of poverty reduction is more obvious and deeper. The extended Solow economic growth model also proved that if the external human capital breaks through the threshold, it can make developing countries get rid of the poverty trap. Therefore, the economic development brought about by health care expenditure must benefit the poor in Sub-Saharan Africa and allow them to enjoy the welfare of social security.

Polarization imaging model considering the non-ideality of polarizers.

Common polarization imaging models are mostly based on an ideal polarizer assumption. This paper proposes a polarization imaging non-ideal model considering the non-ideality of polarizers. The corresponding correction formulas for degree of linear polarization (DoLP) and angle of polarization are also provided. Experiments on linearly polarized light and partially polarized light reflected by a glass plate suggest that when the extinction ratio of polarizers is 100:1, the DoLP relative error of linearly polarized light with the non-ideal model is reduced by 1.87% compared to that with the ideal model; the DoLP relative error of partially polarized light with the non-ideal model is reduced by 1.69% compared to that with the ideal model. Application of the non-ideal model can effectively improve the precision of polarization measurement. In particular, this improvement is more obvious with a low-extinction-ratio (less than 100:1) analyzer.

Polarization properties of reflected light with natural light incidence and elimination of angle of incidence ambiguity.

Polarization imaging technology provides information about not only the irradiance of a target but also the degree of polarization and angle of polarization, which indicate extensive application potential in the field of ocean remote sensing. Natural light can be converted into partially polarized light by the reflection from an interface, and the Fresnel equations can describe the quantitative relationship between the angle of incidence and the degree of polarization of the reflected light. However, the relationship between the angle of polarization and angle of incidence has rarely been studied. In this study, we investigate the polarization state model of reflected light and establish the relationship between the angle of polarization and angle of incidence. This is verified using polarization imaging experiments on a glass plate and calm water surface. The results indicate that the theoretical model agrees well with the experimental results. A method to eliminate the ambiguity of the angle of incidence is proposed based on the model, and its effectiveness and feasibility are verified. It lays the theoretical foundation for imaging detection based on the polarization imaging of transparent media surfaces and sea surface ripples.

Transparent surface orientation from polarization imaging using vector operation.

The existing methods for shape measurement using polarization of transparent objects are based on two assumptions: (1) the paraxial assumption, assuming that the reflected ray is parallel to the optical axis of the imaging system; and (2) the s-component approximation assumption, which assumes that the s-component of the reflected light is predominant and the p-component is neglected. To overcome limitations posed by these two assumptions, this paper proposes a method based on the polarization characteristics of reflection from a transparent surface and vector operation. To overcome the paraxial assumption, the normal vector of the transparent surface is deduced by vector operation, analyzing the relationships between the direction vector of reflection, the normal vector of the reflection plane, the intersection line of the reflection plane and imaging plane, and the normal vector of the transparent surface. To overcome the limitations of the s-component approximation assumption, the angle between the s-component and the polarization direction of the reflected light is analyzed, which yields improved measurement precision. An experiment was performed with transparent targets (flat glass positioned at different angles), and the results show that the measurement error with this method is significantly less than those of existing methods. Thus, we believe this method overcomes the abovementioned limitations while also improving measurement precision.

Theory and analysis of a large field polarization imaging system with obliquely incident light.

Polarization imaging technology provides information about not only the irradiance of a target but also the polarization degree and angle of polarization, which indicates extensive application potential. However, polarization imaging theory is based on paraxial optics. When a beam of obliquely incident light passes an analyser, the direction of light propagation is not perpendicular to the surface of the analyser and the applicability of the traditional paraxial optical polarization imaging theory is challenged. This paper investigates a theoretical model of a polarization imaging system with obliquely incident light and establishes a polarization imaging transmission model with a large field of obliquely incident light. In an imaging experiment with an integrating sphere light source and rotatable polarizer, the polarization imaging transmission model is verified and analysed for two cases of natural light and linearly polarized light incidence. Although the results indicate that the theoretical model is consistent with the experimental results, the theoretical model distinctly differs from the traditional paraxial approximation model. The results prove the accuracy and necessity of the theoretical model and the theoretical guiding significance for theoretical and systematic research of large field polarization imaging.

[FGF-2/PELA/BMP-2 microcapsule scaffold promotes osteogenic differentiation of rat periosteum-derived stem cells in vitro].

OBJECTIVE: To observe the effect of a microencapsule scaffold capable of sustained release of fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 (BMP-2) in promoting the osteogenic differentiation of rat periosteum-derived stem cells (PDSCs) in vitro. METHODS: PDSCs from 4-week-old SD rats, after identification of the surface markers using flow cytometry, were induced to differentiate into osteoblast, chondroblast, and adipocyte lineages. The differentiated cells were verified by staining with Alizarin red, toluidine blue, alcian blue, oil red O and by immunofluorescence assay. FGF-2/PELA/BMP-2, FGF-2/PELA, PELA/BMP-2 and PELA microcapsules were prepared, examined for surface morphologies using scanning electron microscopy (SEM), and tested for controlled release of FGF-2 and BMP-2 using ELISA. The third passage of PDSCs were cultured in the presence of the aqueous extracts of one of the 4 materials, and alkaline phosphatase (AKP) activity in the culture media was detected at 7 and 14 days of culture; the expression levels of osteogenesis-related genes were quantified with quantitative real-time PCR (qRT-PCR). The osteogenic differentiation ability of the PDSCs cultured with the extracts was compared. RESULTS: The PDSCs, which expressed mesenchymal stem cell surface markers, were shown to have osteogenic, chondrogenic and adipogenic differentiation potentials. The cells cultured with the extract of FGF-2/PELA/BMP-2 microcapsules showed the highest AKP activity at 7 and 14 days of culture, and their expression levels of OCN and RunX-2 mRNA were the highest among the 4 groups; RunX-2 expression reached its peak level on day 14, and OCN mRNA expression level increased progressively as the culture time extended. CONCLUSION: FGF-2/PELA/BMP-2 biomimetic controlled release microcapsules preserve the cytokine activities and are capable of promoting the osteogenic differentiation of rat PDSCs.

RGBW Signal Mapping Algorithm Assessment Based on Colorimetry.

With the continuous pursuit of high brightness and low power consumption display technology, RGBW display technology has been attracting increasing attention in the world. Various kinds of displays based on this technology have been produced in the market. The key of this technology is signal mapping algorithm which converts RGB signal into RGBW signal without color distortion and compatible with different sub-pixel layouts. This paper, on the basis of five kinds of signal mapping algorithms, analyzes the mode of action of newly added white sub-pixel affects display color, and the display performance affected by four kinds of sub-pixel layouts; it proposes the corresponding condition of excellent signal mapping algorithm based on colorimetry and deduces the universal equation of excellent signal mapping algorithm and brightness factor which could measure the ability of enhancing brightness. The simulation experiment shows that the signal mapping algorithm which satisfies universal equation could be able to maintain the hue and saturation better. The signal mapping algorithm's ability to enhance brightness is effectively characterized by brightness factor. In conclusion, the proposed universal equation can be used to evaluate existing signal mapping algorithms, and it provides theoretical references for the research of new signal mapping algorithm which could be compatible with different hardware parameters and sub-pixel layouts, promote the popularization of RGBW display technology.

Analysis on clinical characteristics and influencing factors of patients with locoregionally advanced nasopharyngeal carcinoma.

BACKGROUND: To explore the independent prognostic factors for the recurrence/metastasis of patients with locoregionally advanced nasopharyngeal carcinoma (LANPC). MATERIALS AND METHODS: A total of 604 patients initially diagnosed as LANPC by pathohistology in Fujian Provincial Cancer Hospital were selected to analyze the relationship between the clinical pathological patterns, therapeutic protocols and clinical stages with the recurrence/metastasis of LANPC. RESULTS: The 1-, 3- and 5-year locoregionally recurrent rates of LANPC patients were 2.0%, 9.5% and 12.9% respectively, with average recurrent period being 78 months. Univariate analysis results indicated that clinical stages had certain influence on the recurrent period of LANPC patients. However, COX regression models showed that ages, genders and clinical stages were not the independent prognostic factors influencing the recurrence. The 1-, 3- and 5-year metastatic rates of LANPC patients were 6.6%, 17.5% and 18.8% respectively, with average metastatic period of 73 months. Univariate analysis results demonstrated that ages, N stages, clinical stages, locations of lymph node, retropharyngeal lymph node and extracapsular invasion of lymph node had certain influence on the metastatic period of LANPC patients. Additionally, further COX regression analysis results suggested that T stages, reduction protocols and extracapsular invasion of lymph node were the independent prognostic factors influencing the metastasis of patients with LANPC, in which T stages and extracapsular invasion of lymph node were the pestilent factors while reduction protocols the protective factor. CONCLUSIONS: Induction chemotherapy is beneficial to LANPC patients with initial treatment, and the metastatic rate decreases greatly after the application of reduction chemotherapy.

Long-term follow-up and prognostic factors for advanced thymic carcinoma.

The aim of this study was to evaluate the long-term survival outcomes in patients with advanced thymic carcinoma and identify prognostic factors influencing the survival. We retrospectively analyzed 90 consecutive patients with pathologically confirmed advanced thymic carcinoma (Masaoka III and IV) in our institute, from December 2000 to 2012. Age, sex, clinical characteristics, laboratory findings, Masaoka and tumor node metastasis staging, pathologic grade, and treatment modalities were analyzed to identify prognostic factors associated with the progress-free survival (PFS) and the overall survival (OS) rates. Statistical analysis was conducted using SPSS, version 19.0 (SPSS, Inc, Chicago, IL). A total of 73 (81.1%) male and 17 (18.9%) female patients participated in the study. The median follow-up time was 75 months (range, 20-158 months). The 5-year PFS and OS rates were 23.6% (95% confidence interval [CI], 14.6%-33.8%) and 35.7% (95% CI, 25.1%-46.4%), respectively. The multivariate Cox regression model analysis showed that factors improving the PFS were the normal lactate dehydrogenase (LDH) level (P<0.001), Masaoka III stage (P=0.028), and radiotherapy (RT) (P<0.001). The LDH (P<0.001), T stage (P<0.001), and the pathologic grade (P=0.047) were independently prognostic of OS. Long-term follow-up of the advanced thymic carcinoma showed poor outcomes of PFS and OS. LDH, Masaoka stage, and RT affected the PFS, and LDH, T stage, and pathologic grade seemed to affect the OS. Establishing a better staging system for predicting outcomes would be warranted.

[Effects of erythropoietin on serum NSE and S-100B levels in neonates with hypoxic-ischemic encephalopathy].

OBJECTIVE: To study the effects of erythropoietin (EPO) on serum levels of neuron-specific enolase (NSE) and S-100B in neonates with hypoxic-ischemic encephalopathy (HIE) and the underlying mechanism. METHODS: Forty neonates with HIE were randomly divided into conventional treatment (n=20) and EPO treatment groups (n=20). Twenty healthy full-term neonates born during the same period were randomly selected as the normal control group. The conventional treatment group received conventional treatment, while the EPO treatment group received conventional treatment as well as EPO [200 IU/(kg.d)] which was given by intravenous infusion from the second day after birth. The course of treatment was 7 days. Blood samples of the three groups were collected on the first day after birth (before treatment) and the ninth day after birth (after treatment). Serum levels of NSE and S-100B were measured by double-antibody sandwich ABC-ELISA. RESULTS: Before treatment, the two treatment groups had significantly higher serum NSE and S-100B levels than the normal control group (P<0.01), whereas no significant differences in the levels of NSE and S-100B were observed between the conventional treatment and EPO treatment groups (P>0.05). The serum NSE and S-100B levels on the ninth day after birth were significantly lower than those on the first day after birth in the three groups (P<0.01). After treatment, the serum NSE and S-100B levels were significantly lower in the EPO treatment group than in the conventional treatment group (P<0.05). CONCLUSIONS: Dynamic monitoring of serum NSE and S-100B levels may be helpful for the early diagnosis of HIE and the assessment of brain injury repair in newborns with HIE. EPO may be helpful for the repair of neurons and glial cells.

Unique mechanism of the interaction between honey bee toxin TPNQ and rKir1.1 potassium channel explored by computational simulations: insights into the relative insensitivity of channel towards animal toxins.

BACKGROUND: The 21-residue compact tertiapin-Q (TPNQ) toxin, a derivative of honey bee toxin tertiapin (TPN), is a potent blocker of inward-rectifier K(+) channel subtype, rat Kir1.1 (rKir1.1) channel, and their interaction mechanism remains unclear. PRINCIPAL FINDINGS: Based on the flexible feature of potassium channel turrets, a good starting rKir1.1 channel structure was modeled for the accessibility of rKir1.1 channel turrets to TPNQ toxin. In combination with experimental alanine scanning mutagenesis data, computational approaches were further used to obtain a reasonable TPNQ toxin-rKir1.1 channel complex structure, which was completely different from the known binding modes between animal toxins and potassium channels. TPNQ toxin mainly adopted its helical domain as the channel-interacting surface together with His12 as the pore-blocking residue. The important Gln13 residue mainly contacted channel residues near the selectivity filter, and Lys20 residue was surrounded by a polar "groove" formed by Arg118, Thr119, Glu123, and Asn124 in the channel turret. On the other hand, four turrets of rKir1.1 channel gathered to form a narrow pore entryway for TPNQ toxin recognition. The Phe146 and Phe148 residues in the channel pore region formed strong hydrophobic protrusions, and produced dominant nonpolar interactions with toxin residues. These specific structure features of rKir1.1 channel vestibule well matched the binding of potent TPNQ toxin, and likely restricted the binding of the classical animal toxins. CONCLUSIONS/SIGNIFICANCE: The TPNQ toxin-rKir1.1 channel complex structure not only revealed their unique interaction mechanism, but also would highlight the diverse animal toxin-potassium channel interactions, and elucidate the relative insensitivity of rKir1.1 channel towards animal toxins.

Lentiviral miR30-based RNA interference against heparanase suppresses melanoma metastasis with lower liver and lung toxicity.

AIM: To construct short hairpin RNAs (shRNAs) and miR30-based shRNAs against heparanase (HPSE) to compare their safety and their effects on HPSE down-modulation in vitro and in vivo to develop a more ideal therapeutic RNA interference (RNAi) vector targeting HPSE. METHODS: First, we constructed shRNAs and miR30-based shRNAs against HPSE (HPSE-shRNAs and HPSE-miRNAs) and packed them into lentiviral vectors. Next, we observed the effects of the shRNAs on knockdown for HPSE expression, adhesion, migration and invasion abilities in human malignant melanoma A375 cells in vitro. Furthermore, we compared the effects of the shRNAs on melanoma growth, metastasis and safety in xenograft models. RESULTS: Our data showed that these artificial miRNAs targeting HPSE could be effective RNAi agents mediated by Pol II promoters in vitro and in vivo, although these miRNAs were not more potent than the HPSE-shRNAs. It was noted that obvious lung injuries, rarely revealed previously, as well as hepatotoxicity could be caused by lentivirus-mediated shRNAs (LV shRNAs) rather than lentivirus-mediated miRNAs (LV miRNAs) in vivo. Furthermore, enhanced expression of pro-inflammatory cytokines IL-6 and TGF-ß1 and endogenous mmu-miR-21a-5p were detected in lung tissues of shRNAs groups, whereas the expression of mmu-let-7a-5p, mmu-let-7b-5p and mmu-let-7c-5p were down-regulated. CONCLUSION: These findings suggest that artificial miRNAs display an improved safety profile of lowered lung injury or hepatotoxicity relative to shRNAs in vivo. The mechanism of lung injuries caused by shRNAs may be correlated with changes of endogenous miRNAs in the lung. Our data here increase the flexibility of a miRNA-based RNAi system for functional genomic and gene therapy applications.