A broadband folded reflectarray antenna (FRA) is presented employing a novel single-layer cross-polarization conversion (CPC) subwavelength element in this letter. The proposed element has a very simple structure and consists of only a square ring resonator loaded with two splits, thereby realizing easy fabrication with low cost. By varying the length of the ring and mirroring the element, a 360° phase change range is achieved with low losses at the center frequency. These characteristics make the proposed configuration unique, as most of the reported FRA elements rely on complex and multilayer structures to realize the broadband CPC. Furthermore, an FRA using the proposed elements is designed and measured at 22 GHz. A good agreement between the simulated and measured results is obtained. The measured results demonstrate that the proposed FRA realizes a 1 dB gain bandwidth of 20.9% and a maximum aperture efficiency of 47.8%.

A reconfigurable balanced dual-band bandpass filter (BPF) with constant differential-mode (DM) absolute bandwidth (ABW) and high selectivity is designed in this article. The proposed BPF is composed of a set of asymmetric short stub-loaded resonators (A-SSLRs) and balanced microstrip-to-slotline transition structures (MSTSs). Four varactor diodes are employed to achieve the reconfigurable characteristics with small insertion losses. By changing the coupling distances and selecting the positions of the loaded varactor diodes on A-SSLRs, the DM coupling coefficients $K_{i}$ and quality factors $Q_{i}$ of the proposed BPF can be easily controlled to keep a constant DM ABW. In the overall tuning range, a superior common-mode (CM) suppression is achieved intrinsically, and the DM responses are independent of the CM ones. Furthermore, five DM transmission zeros (TZs) are generated by the mixed-coupling and source–load coupling, which can improve the selectivity obviously. Compared with the published reconfigurable balanced BPFs, the proposed one has the advantages of constant DM ABW, smaller insertion losses, and more independent control on the two DM passbands. In order to validate the design strategies, a prototype circuit is designed, fabricated, and measured. The simulated and measured results are presented with a good agreement to verify the theory and design.

Two balanced microstrip dual-band bandpass filters (BPFs) based on short stub loaded resonator (SSLR) and open stub loaded resonator (OSLR) are presented in this paper, respectively. The center frequencies of the two differential-mode (DM) passbands can be controlled quasi-independently by adjusting the lengths of resonators. Moreover, a stepped impedance microstrip line etched with an interdigital coupling line is utilized to introduce a coupling between the two resonators, which generates two extra controlled transmission zeros (TZs) to obtain better selectivities. Furthermore, balanced microstrip/ slotline (MS) transition structures are employed as feed networks, which can suppress common-mode (CM) inherently while the DM responses are not affected, thereby the design procedure can be simplified significantly. In order to demonstrate the theoretical design, two balanced dual-band BPFs were designed and fabricated. The simulated responses are compared with the measured ones and a good agreement is obtained.

We recently proposed a direction-of-arrival (DOA) estimation method for the coexistence of uncorrelated and coherent signals, which is related to the uniform linear antenna arrays with mutual coupling (MC) in the presence of unknown nonuniform noise. This technique, however, relies on the assumption of mixed signals and is not suitable for scenarios with purely coherent signals. This paper extends the mixed signal scenario to the purely coherent signals one on one hand, and on the other hand, allows us to directly adopt the ESPPRIT algorithm to perform DOA estimation in MC environments. To be specific, with the help of the least squares (LS) criterion, the nonuniform noise is first eliminated, and the traditional middle subarray scheme can then be employed to be immune to the influence of MC. Unlike the former operation, following a different line of attack the latter can make full use of the whole array and provide a larger array antenna aperture. Furthermore, we derive a new strategy to directly determine the DOAs without taking MC into account and performing spectral search. This brings substantial benefits to the DOA estimation accuracy and computational cost. The superiority of the proposed approaches is verified by numerical examples.

As a dioxygenase, Ten-Eleven Translocation 2 (TET2) catalyzes subsequent steps of 5-methylcytosine (5mC) oxidation. TET2 plays a critical role in the self-renewal, proliferation, and differentiation of hematopoietic stem cells, but its impact on mature hematopoietic cells is not well-characterized. Here we show that Tet2 plays an essential role in osteoclastogenesis. Deletion of Tet2 impairs the differentiation of osteoclast precursor cells (macrophages) and their maturation into bone-resorbing osteoclasts in vitro. Furthermore, Tet2−/− mice exhibit mild osteopetrosis, accompanied by decreased number of osteoclasts in vivo. Tet2 loss in macrophages results in the altered expression of a set of genes implicated in osteoclast differentiation, such as Cebpa, Mafb, and Nfkbiz. Tet2 deletion also leads to a genome-wide alteration in the level of 5-hydroxymethylcytosine (5hmC) and altered expression of a specific subset of macrophage genes associated with osteoclast differentiation. Furthermore, Tet2 interacts with Runx1 and negatively modulates its transcriptional activity. Our studies demonstrate a novel molecular mechanism controlling osteoclast differentiation and function by Tet2, that is, through interactions with Runx1 and the maintenance of genomic 5hmC. Targeting Tet2 and its pathway could be a potential therapeutic strategy for the prevention and treatment of abnormal bone mass caused by the deregulation of osteoclast activities.

In complex scenes, it is a huge challenge to accurately detect motion-blurred, tiny, and dense objects in the thermal infrared images. To solve this problem, robust thermal infrared vehicle and pedestrian detection method is proposed in this paper. An important weight parameter β is first proposed to reconstruct the loss function of the feature selective anchor-free (FSAF) module in its online feature selection process, and the FSAF module is optimized to enhance the detection performance of motion-blurred objects. The proposal of parameter β provides an effective solution to the challenge of motion-blurred object detection. Then, the optimized anchor-free branches of the FSAF module are plugged into the YOLOv3 single-shot detector and work jointly with the anchor-based branches of the YOLOv3 detector in both training and inference, which efficiently improves the detection precision of the detector for tiny and dense objects. Experimental results show that the method proposed is superior to other typical thermal infrared vehicle and pedestrian detection algorithms due to 72.2% mean average precision (mAP).