•Classification of tooth type from single 3D point cloud model was investigated.•Hierarchical CNN-based occlusal surface morphology was analyzed.•Image augmentations were applied to improve ...classification performance.•Grad-cam demonstrate smaller important region for better generality by augmented images.
3D Digitization of dental model is growing in popularity for dental application. Classification of tooth type from single 3D point cloud model without assist of relative position among teeth is still a challenging task.
In this paper, 8-class posterior tooth type classification (first premolar, second premolar, first molar, second molar in maxilla and mandible respectively) was investigated by convolutional neural network (CNN)-based occlusal surface morphology analysis. 3D occlusal surface was transformed to depth image for basic CNN-based classification. Considering the logical hierarchy of tooth categories, a hierarchical classification structure was proposed to decompose 8-class classification task into two-stage cascaded classification subtasks. Image augmentations including traditional geometrical transformation and deep convolutional generative adversarial networks (DCGANs) were applied for each subnetworks and cascaded network.
Results indicate that combing traditional and DCGAN-based augmented images to train CNN models can improve classification performance. In the paper, we achieve overall accuracy 91.35%, macro precision 91.49%, macro-recall 91.29%, and macro-F1 0.9139 for the 8-class posterior tooth type classification, which outperform other deep learning models. Meanwhile, Grad-cam results demonstrate that CNN model trained by our augmented images will focus on smaller important region for better generality. And anatomic landmarks of cusp, fossa, and groove work as important regions for cascaded classification model.
The reported work has proved that using basic CNN to construct two-stage hierarchical structure can achieve the best classification performance of posterior tooth type in 3D model without assistance of relative position information. The proposed method has advantages of easy training, great ability to learn discriminative features from small image region.
Digital holographic microscopy is widely used for quantitative phase information detection. However, in this technique, phase information is usually concealed by aberrations such as tilt, quadratic ...aberration, and other high-order aberrations. There are few methods that truly capable of total phase aberration compensation. The method based on 1D standard polynomials fitting is one of them. Here, we will study its performance, including the ability of compensating large amount of high-order aberrations, the influence of sample locations and noise. The results are compared with that of the classical 2D Zernike polynomials fitting method. We also give some guidance on sample locations so that the samples are properly located to guarantee the good compensation. Additionally, we thoroughly analyze the similarity and difference between the two methods that both based on the 1D standard polynomials fitting. The results will facilitate the understanding and implement of this type of methods.
Holographic fluorescence imaging is very promising, as it can obtain three-dimensional fluorescence imaging without scanning. However, the current method usually records holograms far from the image ...plane, with the fluorescence decaying when spreading broadly. Here we show that the signal-to-noise ratio (SNR) of fluorescence holography can be improved by recording the high-contrast interferogram near the image plane. We found that this can be achieved by setting the focal length of the lens for the reference wave (f(2)) close to that for the object wave (f(1)). With experiments, we demonstrate an example of an increase of about 21 times in SNR by changing f(2) from infinity to 226 mm, which is close to f(1) (323 mm).
Objective: This study aims to examine the clinical significance of ultrasound evaluation of the gastrocnemius muscle (GM) in identifying sarcopenia in patients with type 2 diabetes (T2D). Methods: ...One hundred and fifty-three patients with T2D were included in this study. We measured the appendicular skeletal muscle mass index (ASMI), handgrip strength, and 6-meter walking speed. The US-derived muscle thickness (MT), cross-sectional area (CSA), and shear wave ultrasound elastography (SWE) of GM were also measured. We assessed the correlations between clinical indicators and US features. The model for screening sarcopenia was established using stepwise logistic regression. Stepwise linear regression was used to identify a set of variables that jointly estimated ASMI. The model's ability to identify sarcopenia and low muscle mass was assessed by receiver operating characteristic (ROC) curve analysis. Results: The prevalence of sarcopenia in this study was 24.2%. The CSA, MT and SWE values of the patients with sarcopenia were lower than those of patients without sarcopenia (all p < 0.05). ASMI was positively correlated with CSA(r = 0.56, p<0.001) and MT (r = 0.39, p < 0.001). Handgrip strength was positively correlated with CSA (r = 0.45, p < 0.001), MT (r = 0.25, p < 0.001), and SWE (r = 0.26, p = 0.002). A diagnostic model for sarcopenia was established with a sensitivity of 81.1%, specificity of 75.0%, and an area under the curve (AUC) of 0.800. The estimated ASMI equation was developed and found to have a positive correlation with actual ASMI (r = 0.70, p < 0.001). It was also effective in diagnosing low muscle mass, with an AUC of 0.787 for males and 0.783 for females. Conclusion: Ultrasonographic assessment of the gastrocnemius muscle was found to be a useful and convenient method for detecting sarcopenia in patients with T2D. Keywords: sarcopenia, ultrasound, shear wave elastography, gastrocnemius muscle, T2D
Human CD4
T cells play an important role in the immune response to Mycobacterium tuberculosis (MTB). However, little is known about the spectratyping characteristics of the CD4
T-cell receptor (TCR) ...α- and β-chains CDR3 region in tuberculosis (TB) patients. We sorted MTB peptide E7-bound CD4
T cells by using E7/HLA-DR tetramers constructed with different HLA-DRB1 alleles and extracted the CDR3 amino-acid sequences of TCR α- and β-chains. The results showed that the CDR3 sequences of E7-bound CD4
T cells were completely or partially identical in a single patient. The sequences of MTB peptide C5-bound CD4
T cells shared another, and non-peptide bound CD4
T cells, as well as unbound CD4
T cells with tetramers were different from each other. Specifically, diverse CDR3 sequences of E7-bound CD4
T cells displayed similar protein tertiary structure in one TB patient. In summary, the TCR α- and β-chains of CDR3 lineage of CD4
T cells in TB patients apparently drifted, and the predominant CDR3 sequences of TCR α- and β-chains that recognized the MTB antigen exhibited peptide specificity, and certain HLA-DR restriction was also established. This study elucidates the possible causes and mechanisms of peptide-specific CD4
T-cell-related presentation against MTB.
Scientific Reports 6: Article number: 23351; published online: 30 March 2016; updated: 22 April 2016 This Article contains typographical errors in a grant number in the Acknowledgements section. ...“This work was supported by grants National Natural Science Foundation of China (331470877, 81172811),” should read:
Mycobacterium tuberculosis is a hard-to-eradicate intracellular pathogen that infects one-third of the global population. It can live within macrophages owning to its ability to arrest phagolysosome ...biogenesis. Autophagy has recently been identified as an effective way to control the intracellular mycobacteria by enhancing phagosome maturation. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-mycobacterial response. Both in vivo and in vitro studies showed that miR-155 expression was significantly enhanced after mycobacterial infection. Forced expression of miR-155 accelerated the autophagic response in macrophages, thus promoting the maturation of mycobacterial phagosomes and decreasing the survival rate of intracellular mycobacteria, while transfection with miR-155 inhibitor increased mycobacterial survival. However, macrophage-mediated mycobacterial phagocytosis was not affected after miR-155 overexpression or inhibition. Furthermore, blocking autophagy with specific inhibitor 3-methyladenine or silencing of autophagy related gene 7 (Atg7) reduced the ability of miR-155 to promote autophagy and mycobacterial elimination. More importantly, our study demonstrated that miR-155 bound to the 3'-untranslated region of Ras homologue enriched in brain (Rheb), a negative regulator of autophagy, accelerated the process of autophagy and sequential killing of intracellular mycobacteria by suppressing Rheb expression. Our results reveal a novel role of miR-155 in regulating autophagy-mediated mycobacterial elimination by targeting Rheb, and provide potential targets for clinical treatment.
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