Radar Micro-Doppler Signature Generation Based on Time-Domain Digital Coding Metasurface.

Micro-Doppler effect is a vital feature of a target that reflects its oscillatory motions apart from bulk motion and provides an important evidence for target recognition with radars. However, establishing the micro-Doppler database poses a great challenge, since plenty of experiments are required to get the micro-Doppler signatures of different targets for the purpose of analyses and interpretations with radars, which are dramatically limited by high cost and time-consuming. Aiming to overcome these limits, a low-cost and powerful simulation platform of the micro-Doppler effects is proposed based on time-domain digital coding metasurface (TDCM). Owing to the outstanding capabilities of TDCM in generating and manipulating nonlinear harmonics during wave-matter interactions, it enables to supply rich and high-precision electromagnetic signals with multiple micro-Doppler frequencies to describe the micro-motions of different objects, which are especially favored for the training of artificial intelligence algorithms in automatic target recognition and benefit a host of applications like imaging and biosensing.

Thread shape affects the stress distribution of torque force on miniscrews: a finite element analysis.

This study aimed to investigate the effect of miniscrews thread shape on the stress distribution receiving a torque load. Seven thread shapes (S,V1,V2,B1,B2,R1,R2) models were constructed and a 6 Nmm-torque load was applied. The order of maximum equivalent stress (EQV) value was V1 > V2 > B1 > R1 > R2 > B2 > S. The order of maximum displacement of miniscrew (Max DM) value was S > B2 > R1 = V1 > B1 > V2 > R2. Model R2 may be the most appropriate thread shape affording a torque force.

Pulmonary Lymphomatoid Granulomatosis With Hemophagocytic Lymphohistiocytosis as the Initial Manifestation.

Lymphomatoid granulomatosis (LYG) is an extremely rare angio-centric and angio-destructive B-cell lymphoproliferative disease. Driven by Epstein-Barr virus (EBV), LYG predominantly involves the bilateral lungs. Commonly presenting as multiple nodules in the lung, pulmonary LYG can masquerade as various infectious diseases, vasculitis, lung cancer, or other metastatic neoplasm. It is difficult to be diagnosed and is always neglected by clinicians. No standardized therapeutic regimens for LYG has been established yet now. Hemophagocytic lymphohistiocytosis (HLH), a life-threatening condition caused by abnormal activation of macrophages and T-cells, is characterized by fever, hepatosplenomegaly, pancytopenia, hypercytokinemia, and the presence of hemophagocytosis within the bone marrow, liver, spleen, or other lymphatic tissue. We herein report a 55-year-old man with recurrent fever, severe jaundice, and multiple high-density opacities and nodules in both lungs, who was finally diagnosed with pulmonary LYG (Grade 3) manifested with secondary HLH. Administration of HLH-1994 protocol led to the rapid control of the symptoms caused by HLH. Rituximab-based combination therapy was useful yet LYG (Grade 3) progressed rapidly. This case demonstrates that tissue biopsy is essential for early pathological diagnosis and effective treatment of LYG.

[MiR-30b Regulates the Cisplatin-Resistance of Human NK/T Cell Lypnphoma Cell Lines SNK-6 and YTS by Targeting the CCL22].

OBJECTIVE: To explore the effect and mechanism of miR-30b on cisplatin-resistance of human NK/T cell lymphoma lines SNK-6 and YTS cells. METHODS: Normal NK cells, SNK-6 and YTS cells were cultured, the expression levels of miR-30b and macrophage-derived chemokine (CCL22) were detected by real-time PCR assay, and the CCL22 expression was detected by Western blot. The SNK-6 and YTS cells were transfected with miR-30b mimics and inhibitor respectively, then the effect of cisplatin resistance in SNK-6 and YTS cells was measured by MTT assay, the activity of caspase-3 was detected by caspase-3 assay kit, and the cell apoptosis was analyzed by flow cytometry. Dual-luciferase reporter gene assay was used to determine the targeting relationship between miR-30b and CCL22. Furthermore, the effect of CCL22 on cisplatin-resistance and caspase-3 actirity was also evaluated. RESULTS: Compared with the normal NK cells, the expression levels of miR-30b significantly decreased in both SNK-6 and YTS cells (P＜0.01), but CCL22 mRNA expression increase in both cells (P＜0.01). MiR-30b mimics decreased the cell activity (P＜0.05), down-regulated the cisplatin-resistance (P＜0.05), and increased cell apoptosis and caspase-3 activity (P＜0.05). The effects of miR-30b inhibitor were contrary to the mimics. Up-regulation of miR-30b expression significantly decreased the luciferase activity in CCL22 3'-UTR-transfected NK cells, but not in Mut-CCL22 3'UTR group, suggesting that CCL22 could act as a direct target of miR-30b. The expressions of CCL22 pathway proteins were down-regulated after SNK-6 cells transfected with miR-30b mimics (P＜0.05), while this effect was restored by overexpression of CCL22. Moreover, CCL22 overexpression also increased the cell activity and decreased caspase-3 activity when SNK-6 cells were transfected with miR-30b mimics. CONCLUSION: MiR-30b inhibits cisplatin-resistance of human NK/TCL SNK-6 and YTS cells by targeting CCL22.

Finite Element Analysis of Bone Stress around Micro-Implants of Different Diameters and Lengths with Application of a Single or Composite Torque Force.

BACKGROUND: Stress on the bone surrounding dental micro-implants affects implant success. PURPOSE: To compare the stress on the bone surrounding a micro-implant after application of a single force (SF) of 200 g or a composite force (CF) of 200 g and 6 N.mm torque. MATERIALS AND METHODS: Finite element models were developed for micro-implant diameters of 1.2, 1.6, and 2.0 mm, and lengths of 6, 8, 10, and 12 mm and either a SF or CF was applied. The maximum equivalent stress (Max EQS) of the bone surrounding the micro-implant was determined, and the relationships among type of force, diameter, and length were evaluated. RESULTS: The Max EQS of the CF exceeded that of the SF (P< 0.05). The effect of force on stress was related to implant diameter, but not to implant length. The larger CF led to greater instability of the micro-implant and the effect was most pronounced at an implant diameter of 1.2 mm. The use of implant diameters of 1.6 mm and 2.0 mm produced no significant difference in implant stability when either a CF or SF was applied. CONCLUSION: When considering the use of an implant to perform three-dimensional control on the teeth, the implant diameter chosen should be > 1.2 mm.

[Influence of the diameter and length of the mini-implant on the primary stability after loading with composite forces].

OBJECTIVE: To investigate the influence of the diameter and length of the mini-implant on the primary stability after loading with composite forces (CF) which contained torque and horizontal forces (HF). METHODS: Ninety-six finite element models were established by the combination of mini-implant and bone, diameters (1.2 mm, 1.6 mm, 2.0 mm) and length (6 mm, 8 mm, 10 mm, 12 mm). There were 12 sizes, each size corresponded with 8 models. Group HF (each size n = 4) was loaded with 1.96 N horizontal force and Group CF (each size n = 4) was loaded with composite force which contained 6 N·mm torque and 1.96 N horizontal force. The maximum displacement of mini-implant with different force directions, implant diameters and lengths were evaluated. RESULTS: The effect of force direction on the displacement related to diameter of mini-implant. The maximum displacement under load with HF respectively was changed with the changing of diameter[1.2 mm: (7.71 ± 0.49) µm; 1.6 mm: (3.94 ± 0.31) µm; 2.0 mm: (2.32 ± 0.43) µm], which were smaller than the maximum displacement of Group CF [1.2 mm: (9.22 ± 0.63) µm; 1.6 mm: (4.62 ± 0.52) µm; 2.0 mm: (2.69 ± 0.49) µm] (P < 0.05). When diameter was 1.2 mm, the difference of the maximum displacement [(1.61 ± 0.22) µm] between Group HF and CF was more obvious than that when the diameter was 1.6 mm or 2.0 mm [(0.64 ± 0.12), (0.49 ± 0.06) µm] (P < 0.05). CONCLUSIONS: The composite force had unfavorable effect on the primary stability of the mini-implant. The diameter of the mini-implant had better be larger than 1.2 mm when the composite forces were applied.