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In this article, a novel design approach to triple-resonant, circular sector patch antenna with wideband null frequency scanning functionality is advanced. At first, the operation principle of null frequency scanning functionality is revealed by the simplest, straight electric dipole under multiple resonances. Then, a triple-resonant circular sector patch antenna is designed based on a double-wavelength prototype magnetic dipole by synthesizing it usable resonant modes. As synthesized, the resonant TM12/17,1, TM36/17,1, and TM60/17,1 modes within a 255° circular sector patch radiator can be simultaneously excited, properly perturbed, and then used to realize a wideband null frequency scanning functionality. Next, different prototype antennas are designed and fabricated and experimentally verified the design approach on a single layered air substrate. As finally demonstrated, the antenna can exhibit a null frequency scanning range from $\theta =+ 35^{\circ }$ to −60° within an available radiation bandwidth (ARB) of 24% (i.e., 2.20–2.80 GHz) for null depth smaller than −10 dB. [ABSTRACT FROM AUTHOR]

Image segmentation remains an important, but hard-to-solve, problem since it appears to be application dependent with usually no a priori information available regarding the image structure. In recent years, many image segmentation algorithms have been developed, but they are often very complex and some undesired results occur frequently. In this paper, we propose a pixel classification based color image segmentation using quaternion exponent moments. Firstly, the pixel-level image feature is extracted based on quaternion exponent moments (QEMs), which can capture effectively the image pixel content by considering the correlation between different color channels. Then, the pixel-level image feature is used as input of twin support vector machines (TSVM) classifier, and the TSVM model is trained by selecting the training samples with Arimoto entropy thresholding. Finally, the color image is segmented with the trained TSVM model. The proposed scheme has the following advantages: (1) the effective QEMs is introduced to describe color image pixel content, which considers the correlation between different color channels, (2) the excellent TSVM classifier is utilized, which has lower computation time and higher classification accuracy. Experimental results show that our proposed method has very promising segmentation performance compared with the state-of-the-art segmentation approaches recently proposed in the literature. [ABSTRACT FROM AUTHOR]

Abstract: Most parameters of steel tube can be acquired from the computer tomography (CT) image of its section. However, a large number of projections are needed to reconstruct the image, so the collection and calculation of the projection data consume too much time to inspect steel tube online. For the purpose of solving the problem, we adopt the CT system that can collect the projection data without mechanical scanning motion and propose a modified penalized exponential EM (PEEM) algorithm to reconstruct the steel tube section from only three projections. In the method, the image area is restricted and the pixel value is binarized in order to decrease the number of projections needed and accelerate the convergence speed. At last, the problems of flaw inspection, influence of the restricted area and spatial resolution are discussed. The experiment results show that the accuracy and the reconstruction time of the algorithm meet the requirements of online inspection of steel tube, so it might be possible to be used in practical production. [Copyright &y& Elsevier]

Primary failure of eruption (PFE) is a rare disorder that is characterized by the inability of a molar tooth/teeth to erupt to the occlusal plane or to normally react to orthodontic force. This condition is related to hereditary factors and has been extensively researched over many years. However, the etiological mechanisms of pathogenesis are still not fully understood. Evidence from studies on PFE cases has shown that PFE patients may carry parathyroid hormone 1 receptor (PTH1R) gene mutations, and genetic detection can be used to diagnose PFE at an early stage. PTH1R variants can lead to altered protein structure, impaired protein function, and abnormal biological activities of the cells, which may ultimately impact the behavior of teeth, as observed in PFE. Dental follicle cells play a critical role in tooth eruption and root development and are regulated by parathyroid hormone-related peptide (PTHrP)–PTH1R signaling in their differentiation and other activities. PTHrP–PTH1R signaling also regulates the activity of osteoblasts, osteoclasts and odontoclasts during tooth development and eruption. When interference occurs in the PTHrP–PTH1R signaling pathway, the normal function of dental follicles and bone remodeling are impaired. This review provides an overview of PTH1R variants and their correlation with PFE, and highlights that a disruption of PTHrP–PTH1R signaling impairs the normal process of tooth development and eruption, thus providing insight into the underlying mechanisms related to PTH1R and its role in driving PFE. [ABSTRACT FROM AUTHOR]

Accurate segmentation of industrial CT images is of great significance in industrial fields such as quality inspection and defect analysis. However, reconstruction of industrial CT images often suffers from typical metal artifacts caused by factors like beam hardening, scattering, statistical noise, and partial volume effects. Traditional segmentation methods are difficult to achieve precise segmentation of CT images mainly due to the presence of these metal artifacts. Furthermore, acquiring paired CT image data required by fully supervised networks proves to be extremely challenging. To address these issues, this paper introduces an improved CycleGAN approach for achieving semi-supervised segmentation of industrial CT images. This method not only eliminates the need for removing metal artifacts and noise, but also enables the direct conversion of metal artifact-contaminated images into segmented images without the requirement of paired data. The average values of quantitative assessment of image segmentation performance can reach 0.96645 for Dice Similarity Coefficient(Dice) and 0.93718 for Intersection over Union(IoU). In comparison to traditional segmentation methods, it presents significant improvements in both quantitative metrics and visual quality, provides valuable insights for further research. [ABSTRACT FROM AUTHOR]

Graves' disease (GD) is one of the most common autoimmune conditions, but the mechanisms underlying the associated induction of autoimmunity are not known. We explored the role of peripheral lymphocyte subpopulations in disease pathogenesis. In total, 32 patients and 40 age- and sex-matched healthy controls were recruited in this study. Peripheral levels of T, B, NK, CD4+ T, CD8+ T, Th1, Th2, Th17, and Treg cells were measured using flow cytometry. For all patients, we compared all lymphocyte subpopulations between GD patients and healthy controls. Changes in patient lymphocyte subsets were compared before and after treatment. The absolute numbers of circulating Th17 cells (0.45 ± 1.16, p > 0.05) between GD patients and healthy controls were not significantly different. However, the percentage of Th17 cells was significantly increased (0.25 ± 0.11, p < 0.05). The absolute numbers and percentages of circulating Tregs in GD patients were significantly decreased compared with those in healthy participants (11.61 ± 2.75, p < 0.05). There was a significant difference in Treg absolute numbers between the untreated and drug-treated groups. Furthermore, we found that the Treg percentage in untreated patients (mean=4.78) was not significantly different from that in the drug-treated group (mean=4.81). In addition, circulating Treg absolute numbers in GD patients with exophthalmos were significantly lower than those in GD patients without exophthalmos (9.96 ± 4.16, p < 0.05). A similar trend was observed in GD patients with weight loss (11.97 ± 3.28, p < 0.05). GD pathogenesis was associated with a lower Treg population and an increased Th17/Treg ratio (T helper cell 17/ regulatory T cells). Th17 cells in this study were not related to the disease. Furthermore, anti-thyroid drug therapy improved immune-mediated system disorders. Finally, we found lower absolute numbers of circulating Tregs in GD patients with certain positive signs, such as exophthalmos and/or weight loss. Thus, immune changes are correlated with partial clinical manifestations. • The pathogenesis of Graves'disease is associated with lower Treg absolute counts and increased ratio of Th17/Treg. • Th17 cells in this study were proved to be not related to the disease. • Antithyroid drug therapy may improve immune-mediated system disorders to some extent. • The absolute counts of Tregs in peripheral blood of Graves'disease patients with some positive signs was reduced. [ABSTRACT FROM AUTHOR]

We studied and compared the transport properties of charge carriers in bilayer graphene, monolayer graphene, and the conventional semiconductors (the two-dimensional electron gas (2DEG)). It is elucidated that the normal incidence transmission in the bilayer graphene is identical to that in the 2DEG but totally different from that in the monolayer graphene. However, resonant peaks appear in the non-normal incidence transmission profile for a high barrier in the bilayer graphene, which do not occur in the 2DEG. Furthermore, there are tunneling and forbidden regions in the transmission spectrum for each material, and the division of the two regions has been given in the work. The tunneling region covers a wide range of the incident energy for the two graphene systems, but only exists under specific conditions for the 2DEG. The counterparts of the transmission in the conductance profile are also given for the three materials, which may be used as high-performance devices based on the bilayer graphene. [ABSTRACT FROM AUTHOR]

In this paper, a quantitative precipitation estimation based on the hydrometeor classification (HCA-QPE) algorithm was proposed for the first operational S band dual-polarization radar upgraded from the CINRAD/SA radar of China. The HCA-QPE algorithm, localized Colorado State University-Hydrometeor Identification of Rainfall (CSUHIDRO) algorithm, the Joint Polarization Experiment (JPOLE) algorithm, and the dynamic Z-R relationships based on variational correction QPE (DRVC-QPE) algorithm were evaluated with the rainfall events from March 1 to October 30, 2017 in Guangdong Province. The results indicated that even though the HCA-QPE algorithm did not use the observed rainfall data for correction, its estimation accuracy was better than that of the DRVC-QPE algorithm when the rainfall rate was greater than 5 mm h-1; and the stronger the rainfall intensity, the greater the QPE improvement. Besides, the HCA-QPE algorithm worked better than the localized CSU-HIDRO and JPOLE algorithms. This study preliminarily evaluated the improved accuracy of QPE by a dual-polarization radar system modified from CINRAD-SA radar. [ABSTRACT FROM AUTHOR]

Segmentation involves separating an object from the background in a given image. Image segmentation has a variety of applications and has received considerable attention in multimedia application and computer vision. Although numerous approaches have been introduced, image segmentation is still far from being solved due to most of image segmentation algorithms are often so complicated and some unsatisfactory results appear frequently. Therefore, developing a suitable technique of image segmentation is still a challenging problem. In this article, a novel color image segmentation will be introduced based on quaternion radial harmonic Fourier moments (QRHFMs) and proximal classifier. Firstly, the image feature of pixel-level is represented by the accurate and invariant QRHFMs holistically as a vector field, which can describe sufficiently the image pixel information due to take into account the relationship among different color channels. Secondly, the image feature from pixel-level is utilized as the input of the proximal classifier with consistency (PCC), which not only has lower computation time but also has better generalization compared to traditional support vector machines classifiers. Then, we choose the training samples by Tsallis entropy thresholding to train PCC classification model. Finally, the color image is classified by the trained PCC classification model. Our algorithm can make full use of the accurate and robust local image feature, as well the quickness and generalization ability of PCC classifier. A series of experimental results shows that this algorithm has better segmentation performance than the state-of-the-art method from the literature. [ABSTRACT FROM AUTHOR]

First, based on routine meteorological data, the synoptic characteristics of a heavy warm-sector rainfall that occurred on June 13, 2008 in the Pearl River Delta were analyzed. Second, a mesoscale numerical model, Weather Research and Forecasting (WRFV2.2), was used to simulate the heavy rainfall. Diagnostic analyses were done of moist potential vorticity (MPV) for its horizontal components (MPV2) and vertical components (MPV1) based on the simulation results of WRFV2.2 to identify the mechanism of the rainfall development. The results showed that the heavy rainfall occurred when there were high MPV1 in the upper levels and low MPV1 and high MPV2 in the lower levels. Disturbances of high MPV1 in the upper levels came from the southwest or northwest, those of low MPV1 in the lower levels came from the southwest, and those of high MPV2 came from the south. Disturbances of low MPV1 at low levels were the direct cause of convective instability. Enhanced vertical shear of meridional wind led to increased MPV2 at lower levels, strengthened baroclinicity, and active warm and wet flows. These distributions of MPV helped to trigger the release of unstable energy and produce warm-sector heavy rainfall. As it integrates the evolution of dynamic and thermal fields, MPV is able to reveal the development of this heavy rainfall effectively. [ABSTRACT FROM AUTHOR]

Abstract: The practicality of using juvenile in vitro embryo transfer (JIVET) on a field scale in China was evaluated in each of three seasons (summer, autumn and winter) from 2006 to 2007. A total of 102 donor Merino lambs (18 summer, 69 autumn and 15 winter) aged 4–8 weeks were stimulated with 4×40mg FSH administered at 12h intervals plus 400IU PMSG given at the time of the first FSH treatment. Overall, 89.2% (91/102) of the lambs exhibited follicle development and 79.1±65.5 (mean±S.D.) cumulus–oocyte complexes were recovered per donor lamb. Compared with the groups of summer (84.9±55.3) and autumn (83.6±70.8) lambs, the number of recovered cumulus–oocyte complexes was significantly decreased in winter (51.4±43.7; p <0.05). After recovery, the cumulus–oocyte complexes were matured and fertilized in vitro using frozen–thawed semen and culture in synthetic oviduct fluid medium to the 2–4-c stage of development, when they were transferred surgically in groups of 3–8 (5.33±1.47) to the ipsilateral uterine horn of a total of 603 synchronized recipients. The overall mean proportion of cumulus–oocyte complexes developing to 2-c embryos was 61.4% (4308/7013) and differed significantly between seasons (summer 38.5%, autumn 66.1%, winter 74.6%; p <0.01). Pregnancy rate assessed by ultrasound examination approximately 60 days after embryo transfer was 54.4% (328/603) overall, and 36.7% (221/603) of the recipients maintained their pregnancy to full-term, producing an average 1.49 (330/221) offspring, of which 1.21 (267/221) were viable and healthy lambs, per pregnant recipient. Pregnancy rate at day 60 was affected by season (summer 40.5%, autumn 56.7%, winter 55.7%; p <0.05), but did not differ significantly between seasons at full-term (summer 34.2%, autumn 38.9%, winter 30.4%; p >0.05). Based on the number of donors stimulated, the total number of offspring and viable progeny produced per donor lamb in autumn (5.81 and 4.87) was significantly (p <0.01) higher than that of summer (2.79 and 1.94) and winter (4.24 and 3.31). This study showed that each donor lamb after stimulation produced an average of 48.6 transferable embryos that resulted in 4.04 viable and healthy progeny. These results indicate that JIVET is a cost-effective method of multiplying desirable sheep genotypes in China. [Copyright &y& Elsevier]