A Broadband Dual Circularly Polarized Conical Four-Arm Sinuous Antenna

A novel wideband four-arm sinuous antenna with dual circular polarizations (CPs) and unidirectional radiation is proposed. Different from the conventional designs, this sinuous antenna is realized in a conical form and no ground plane or absorptive cavity is required to obtain unidirectional radiation. The beamforming network for dual circularly polarized operations consists of a wideband quadrature coupler and two wideband baluns, and an auxiliary feeding patch is introduced to facilitate the connection between baluns and sinuous arms. The design of baluns and coupler is inspired from the printed exponentially tapered microstrip balun and broadside-coupled microstrip coupler, respectively. The dynamic differential evolution algorithm is employed to optimize the geometry of coupler for optimal performance. For both polarizations, the presented antenna has wide impedance bandwidth, good axial ratio, moderate realized gain, and front-to-back ratio within 2–5 GHz. An antenna prototype is fabricated and tested. The agreement between simulation and measurement results validates the proposed antenna framework. The demonstrated antenna has advantages of wide bandwidth, dual CPs, unidirectional radiation, lightweight, and low cost, and is promising for applications in wireless systems

CPW-fed wideband circularly-polarized antenna

A novel shorted CPW-fed slot antenna with wideband circular polarization characteristic is proposed in this letter. The proposed antenna consists of a bi-directional radiation slot antenna printed on a single substrate and a reflector for unidirectional radiation. A half circle slot and a slim slot are involved to optimize the axial ratio (AR) bandwidth and taper on the feeding line is utilised to further improve the impedance bandwidth. The measured results show that the antenna has the impedance bandwidth (S11 <; -10dB) of 12.6% and the AR bandwidth (AR <; 3dB) of 12.7%. The RHCP gain in the main radiation direction is 7.5 dBi.

A Review of Key Technologies for High-Speed Motorized Spindles of CNC Machine Tools

The high-speed and high-precision motorized spindle is the future development trend of the CNC machine tool field, and has become the focus of research in the world. High-speed motorized spindles tend to develop in the direction of high precision, high speed, low energy consumption, high efficiency, and high reliability. We undertake a through, systematic review of the development history perspective of the research on precision bearing technology, dynamic balancing technology, thermal error measurement and compensation technology with regard to the key technologies of high-speed motorized spindles. On this basis, the current level of development of key technologies for high-speed motorized spindles is analyzed, and the objective advantages and disadvantages of existing technologies are summarized. Finally, the development tendency of high-speed motorized spindle technology is predicted and foreseen

Quantitative Surface Crack Evaluation Based on Eddy Current Pulsed Thermography

Eddy current pulsed thermography (ECPT) is an emerging non-destructive testing technology and has an increasing span of application with capabilities of rapid contactless and large surface area detection. The close process loop of ECPT that contains pre-processing, post-processing, and objective quantitative assessment is rarely presented. This paper proposed a complete strategy aims to perform pre- and post- processing for surface crack detection based on ECPT platform. In addition, the quantitative evaluation is involved to objectively evaluate detectability. Specially, a new post-image segmentation algorithm is proposed which based on the idea of grouping histogram and iterative adaption approach that leads to better performance for quantitatively identifying and sizing the defect. Experimental tests on man-made metal and natural defects have been conducted to show the reliability of the proposed strategy. This paper can be further applied for other types of defects detection, quantitative evaluation, and aid in the development of machine vision industry for automated visual inspection

Automatic seeded region growing for thermography debonding detection of CFRP

The carbon fiber reinforced polymer (CFRP) has been widely used in aerospace, automobile and sports industries. In laminated composite materials, cyclic stresses and impact will cause internal defects such as delamination and debonding. In order to guarantee internal quality and safety, optical pulsed thermography (OPT) nondestructive testing has been used to detect the internal defects. However, current OPT methods cannot efficiently tackle the influence from uneven illumination, and the resolution enhancement of the defects detection remains as a critical challenge. In this paper, a hybrid of thermographic signal reconstruction (TSR) and automatic seeded region growing (ASRG) algorithm is proposed to deal with the thermography processing of CFRP. The proposed method has the capability to significantly minimize uneven illumination and enhance the detection rate. In addition, it has the capacity to automate segmentation of defects. It also overcomes the crux issues of seeded region growing (SRG) which can automatically select the growth of image, seed points and thresholds. The probability of detection (POD) has been derived to measure the detection results and this is coupled with comparison studies to verify the efficacy of the proposed method

Transcriptional profiling of human peripheral blood mononuclear cells in household contacts of pulmonary tuberculosis patients provides insights into mechanisms of Mycobacterium tuberculosis control and elimination

ABSTRACTHousehold contacts (HHCs) of patients with active tuberculosis (ATB) are at higher risk of Mycobacterium tuberculosis (M. tuberculosis) infection. However, the immune factors responsible for different defense responses in HHCs are unknown. Hence, we aimed to evaluate transcriptome signatures in human peripheral blood mononuclear cells (PBMCs) of HHCs to aid risk stratification. We recruited 112 HHCs of ATB patients and followed them for 6 years. Among the HHCs, only 2 developed ATB, while the remaining HHCs were classified into three groups: (1) HHC-1 group (n = 23): HHCs with consistently positive T-SPOT.TB test, negative chest radiograph, and no clinical symptoms or evidence of ATB during the 6-year follow-up period; (2) HHC-2 group (n = 15): HHCs with an initial positive T-SPOT result that later became negative without evidence of ATB; (3) HHC-3 group (n = 14): HHCs with a consistently negative T-SPOT.TB test and no clinical or radiological evidence of ATB. HHC-2 and HHC-3 were combined as HHC-23 group for analysis. RNA sequencing (RNA-seq) in PBMCs, with and without purified protein derivative (PPD) stimulation, identified significant differences in gene signatures between HHC-1 and HHC-23. Gene ontology analysis revealed functions related to bacterial pathogens, leukocyte chemotaxis, and inflammatory and cytokine responses. Modules associated with clinical features in the HHC-23 group were linked to the IL-17 signaling pathway, ferroptosis, complement and coagulation cascades, and the TNF signaling pathway. Validation using real-time PCR confirmed key genes like ATG-7, CXCL-3, and TNFRSF1B associated with infection outcomes in HHCs. Our research enhances understanding of disease mechanisms in HHCs. HHCs with persistent latent tuberculosis infection (HHC-1) showed significantly different gene expression compared to HHCs with no M. tuberculosis infection (HHC-23). These findings can help identify HHCs at risk of developing ATB and guide targeted public health interventions

Jiangrines A–F and Jiangolide from an Actinobacterium, <i>Jiangella gansuensis</i>

Seven new compounds, including five pyrrol-2-aldehyde derivatives, jiangrines A–E (<b>1</b>–<b>5</b>), one indolizine derivative, jiangrine F (<b>7</b>), and one glycolipid, jiangolide (<b>8</b>), along with a known compound, pyrrolezanthine (<b>6</b>), were isolated from the fermentation broth of <i>Jiangella gansuensis</i>, an actinobacterium assigned to a novel family, Jiangellaceae, and a novel order, Jiangellales. The structures were elucidated by detailed spectroscopic analysis and through chemical methods. Compounds <b>1</b>, <b>2</b>, <b>3</b>/<b>4</b>, <b>5</b>, <b>6</b>, and <b>8</b> demonstrated inhibitory effects on lipopolysaccharide-induced NO production in RAW 264.7 macrophage cells, with IC₅₀ values of 97.8, 60.7, 30.1, 54.9, 58.8, and 61.4 μM, respectively

A Dual Inhibitor of DYRK1A and GSK3β for β-Cell Proliferation: Aminopyrazine Derivative GNF4877

Loss of β-cell mass and function can lead to insufficient insulin levels and ultimately to hyperglycemia and diabetes mellitus. The mainstream treatment approach involves regulation of insulin levels; however, approaches intended to increase β-cell mass are less developed. Promoting β-cell proliferation with low-molecular-weight inhibitors of dual-specificity tyrosine-regulated kinase 1A (DYRK1A) offers the potential to treat diabetes with oral therapies by restoring β-cell mass, insulin content and glycemic control. GNF4877, a potent dual inhibitor of DYRK1A and glycogen synthase kinase 3β (GSK3β) was previously reported to induce primary human β-cell proliferation in vitro and in vivo. Herein, we describe the lead optimization that lead to the identification of GNF4877 from an aminopyrazine hit identified in a phenotypic high-throughput screening campaign measuring β-cell proliferation

A Dual Inhibitor of DYRK1A and GSK3β for β‐Cell Proliferation: Aminopyrazine Derivative GNF4877

Loss of β-cell mass and function can lead to insufficient insulin levels and ultimately to hyperglycemia and diabetes mellitus. The mainstream treatment approach involves regulation of insulin levels; however, approaches intended to increase β-cell mass are less developed. Promoting β-cell proliferation with low-molecular-weight inhibitors of dual-specificity tyrosine-regulated kinase 1A (DYRK1A) offers the potential to treat diabetes with oral therapies by restoring β-cell mass, insulin content and glycemic control. GNF4877, a potent dual inhibitor of DYRK1A and glycogen synthase kinase 3β (GSK3β) was previously reported to induce primary human β-cell proliferation in vitro and in vivo. Herein, we describe the lead optimization that lead to the identification of GNF4877 from an aminopyrazine hit identified in a phenotypic high-throughput screening campaign measuring β-cell proliferation