In current off-axis system design process, optical path configuration (OPC) of the system often remains unchanged due to the explicit physical constraints added in the optimization process, and this ...prevents designers from obtaining potential better results with other OPCs. In this paper, we present a method to change the OPC automatically by ray-quadrangle-based optimization. In our method, a vector is utilized to represent the OPC and a penalty function based on the difference between the current vector and its target value is added into the optimization error function. During OPC variation, obscuration can be avoided without human interference. Examples are given as validation of the proposed method.
Significance: Digital holographic microscopy is widely used to get the quantitative phase information of transparent cells.
Aim: However, the sample phase is superimposed with aberrations. To ...quantify the phase information, aberrations need to be fully compensated.
Approach: We propose a technique to obtain aberration-free phase imaging, using the derivative-based principal component analysis (dPCA).
Results: With dPCA, almost all aberrations can be extracted and compensated without requirements on background segmentation, making it efficient and convenient.
Conclusions: It solves the problem that the conventional principal component analysis (PCA) algorithm cannot compensate the common but intricate higher order cross-term aberrations, such as astigmatism and coma. Moreover, the dPCA strategy proposed here is not only suitable for aberration compensation but also applicable for other cases where there exist cross-terms that cannot be analyzed with the PCA algorithm.
The in vivo kinetics of antigen-presenting cells (APCs) in patients with advanced and convalescent tuberculosis (TB) is not well characterized. In order to target Mycobacterium tuberculosis (MTB) ...peptides- and HLA-DR-holding monocytes and macrophages, 2 MTB peptide-specific CD4(+) T-cell receptor (TCR) tetramers eu and hu were successfully constructed. Peripheral blood (PBL) samples from inpatients with advanced pulmonary TB (PTB) were analyzed using flow cytometry, and the percentages of tetramer-bound CD14(+) monocytes ranged from 0.26-1.44% and 0.21-0.95%, respectively; significantly higher than those measured in PBL samples obtained from non-TB patients, healthy donors, and umbilical cords. These tetramers were also able to specifically detect macrophages in situ via immunofluorescent staining. The results of the continuous time-point tracking of the tetramer-positive rates in PBL samples from active PTB outpatients undergoing treatment show that the median percentages were at first low before treatment, increased to their highest levels during the first month, and then began to decrease during the second month until finally reaching and maintaining a relatively low level after 3-6 months. These results suggest that there is a relatively low level of MTB-specific monocytes in advanced and untreated patients. Further experiments show that MTB induces apoptosis in CD14(+) cells, and the percentage of apoptotic monocytes dramatically decreases after treatment. Therefore, the relatively low level of MTB-specific monocytes is probably related to the apoptosis or necrosis of APCs due to live bacteria and their growth. The bactericidal effects of anti-TB drugs, as well as other unknown factors, would induce a peak value during the first month of treatment, and a relatively low level would be subsequently reached and maintained until all of the involved factors reached equilibrium. These tetramers have diagnostic potential and can provide valuable insights into the mechanisms of antigen presentation and its relationship with TB infection and latent TB infection.
Virus-specific T cells play essential roles in protection against multiple virus infections, including SARS-CoV and MERS-CoV. While SARS-CoV-2-specific T cells have been identified in COVID-19 ...patients, their role in the protection of SARS-CoV-2-infected mice is not established. Here, using mice sensitized for infection with SARS-CoV-2 by transduction with an adenovirus expressing the human receptor (Ad5-hACE2), we identified SARS-CoV-2-specific T cell epitopes recognized by CD4+ and CD8+ T cells in BALB/c and C57BL/6 mice. Virus-specific T cells were polyfunctional and were able to lyse target cells in vivo. Further, type I interferon pathway was proved to be critical for generating optimal antiviral T cell responses after SARS-CoV-2 infection. T cell vaccination alone partially protected SARS-CoV-2-infected mice from severe disease. In addition, the results demonstrated cross-reactive T cell responses between SARS-CoV and SARS-CoV-2, but not MERS-CoV, in mice. Understanding the role of the T cell response will guide immunopathogenesis studies of COVID-19 and vaccine design and validation.
Vehicle exhaust emission is one of the major atmospheric pollution sources. Excessive emitters, which make up 10 percent of all vehicles, contribute more than half of the total pollution emission. To ...identify these excessive emitters, a remote‐sensing device (RSD) with a laser wavelength around 1580 nm is built. To increase the system sensitivity, a segment modulation method is proposed so that the 2f signals of CO2 and CO can be optimized, respectively. In vitro tests show that the linearity reached .999 and .998 for CO2 and CO, respectively. A field test is also conducted to monitor the dilution process of exhaust emission after the vehicle passes the RSD.
Digital holography is a well-accepted method for phase imaging. However, the phase of the object is always embedded in aberrations. Here, we present a digital holographic phase imaging with the ...aberrations fully compensated, including the high order aberrations. Instead of using pre-defined aberration models or 2D fitting, we used the simpler and more flexible 1D fitting. Although it is 1D fitting, data across the whole plane could be used. Theoretically, all types of aberrations can be compensated with this method. Experimental results show that the aberrations have been fully compensated and the pure object phase can be obtained for further studies.
In the context of agricultural digitalisation in China, TikTok is becoming widely popular in rural areas and a novel way for agricultural technology extension. Based on survey data on 770 rice and ...wheat farmers in Hubei and Henan provinces in China, the endogenous switching probit model was used to verify the influence of TikTok usage on the adoption of Green Control Techniques (GCT). We found that farmers' adoption probability of GCT will be significantly increased by 9.3-11.8% with their use of TikTok to browse GCT content. This shows that TikTok is an effective way to extend GCT. Furthermore, TikTok can complement traditional offline training as a digital agriculture extension for small-scale, older, and non-plain-area farmers, who are often of unequal status and are unable to obtain government agricultural extension services. These findings evaluate the effectiveness of short video software as a digital agriculture extension platform, which contributes to the rapid and effective extension of GCT. It is suggested that more GCT online promotion platforms should be built and applied in China.
We propose a structured illumination differential interference contrast (SI-DIC) microscopy, breaking the diffraction resolution limit of differential interference contrast (DIC) microscopy. SI-DIC ...extends the bandwidth of coherent transfer function of the DIC imaging system, thus the resolution is improved. With 0.8 numerical aperture condenser and objective, the reconstructed SI-DIC image of 53 nm polystyrene beads reveals lateral resolution of approximately 190 nm, doubling that of the conventional DIC image. We also demonstrate biological observations of label-free cells with improved spatial resolution. The SI-DIC microscopy can provide sub-diffraction resolution and high contrast images with marker-free specimens, and has the potential for achieving sub-diffraction resolution quantitative phase imaging.
Caries grading plays a significant role for oral health management and treatment planning. Grading caries on panoramic image is a challenging task due to complication and diversity of gray ...distribution. In this paper, we proposed an automatic and visualized caries grading method for panoramic image using deep learning-based tooth anatomical segmentation and regions intersection judgment to achieve a consistent grading process with dentist. To achieve accurate semantic segmentation, a modified U-Net model by adding ASPP module and boundary loss is applied to segment caries, enamel, dentin, and pulp tissue region. Then a visualized process is conducted to judge the intersection of carious region and decision-making line for grading of shallow, medium, deep caries. Experimental results demonstrate our method achieves promising grading performance. Moreover, we validated that our proposed two-stage caries grading method outperform deep learning classification models. Ablation analysis of anatomical segmentation performance was also investigated, and the compared results show that our proposed modified U-Net model can obtain more accurate region and boundary to improve grading results. Some mis-graded cases were finally detailed analyzed. Our proposed caries grading approach has great potential for clinical aided diagnosis and automatic chart filling on panoramic radiographs.
Macrophages play a crucial role in host innate anti-mycobacterial defense, which is tightly regulated by multiple factors, including microRNAs. Our previous study showed that a panel of microRNAs was ...markedly up-regulated in macrophages upon mycobacterial infection. Here, we investigated the biological function of miR-146a during mycobacterial infection. miR-146a expression was induced both in vitro and in vivo after Mycobacterium bovis BCG infection. The inducible miR-146a could suppress the inducible nitric oxide (NO) synthase (iNOS) expression and NO generation, thus promoting mycobacterial survival in macrophages. Inhibition of endogenous miR-146a increased NO production and mycobacterial clearance. Moreover, miR-146a attenuated the activation of nuclear factor κB and mitogen-activated protein kinases signaling pathways during BCG infection, which in turn repressed iNOS expression. Mechanistically, miR-146a directly targeted tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) at post-transcriptional level. Silencing TRAF6 decreased iNOS expression and NO production in BCG-infected macrophages, while overexpression of TRAF6 reversed miR-146a-mediated inhibition of NO production and clearance of mycobacteria. Therefore, we demonstrated a novel role of miR-146a in the modulation of host defense against mycobacterial infection by repressing NO production via targeting TRAF6, which may provide a promising therapeutic target for tuberculosis.
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