Modeling simulation and experiment of micro-Doppler signature of precession

Spatial precession is a special micro-motion of the spinning-directional target,and the micro-Doppler signature of the cone-shaped target with precession is studied.The micro-motion model of precession is built first,and then the micro-Doppler model is developed based on the proposed concept of micro-motion matrix,by which the theoretical formula of micro-Doppler signature of precession is derived.In order to further approach to the actual case,the occlusion effect is firstly considered in micro-Doppler,and the simulated result with occlusion effect is well in accordance with the measured result in microwave anechoic chamber,which suggests that the micro-motion model and micro-Doppler model of precession are both valid.

Efficient Computation of Scattering from Targets with Negative Impedance Surface

Current surface integral equations used for computing scattering from targets with negative impedance boundary condition(IBC)are not efficient.A modified surface dual integral equation(M-SDIE)for targets with negative IBC is presented.A pure imaginary number is used to balance the formulations.It is proved that the M-SDIE is accurate and efficient with three numerical examples.The first numerical example shows that the M-SDIE is accurate compared with Mie.The second example shows that the presented SIE is efficient.In the third example,a missile head is selected to present the computing power of the M-SDIE.All the examples show that the M-SDIE is an efficient algorithm for negative IBC.

Analysis of Large Slotted-Waveguide Antenna Arrays Using the Parallel DDA-FE-BI-MLFMA

An efficient analyzing approach is presented for large slotted-waveguide antenna arrays by using hybrid finite element-boundary integral-multilevel fast multipole algorithm(FE-BI-MLFMA)in this paper.A simple computation model for slotted-waveguide antenna is presented by using thin current probe excitation and perfectly matched layer(PML)absorber.Since each slotted-waveguide antenna can be considered as a single sub-domain,the domain decomposition algorithm(DDA)can be applied to FE-BI-MLFMA to greatly reduce the computation resources and achieve high efficiency.This DDA-FE-BI-MLMFA is parallelized to further strength its capability.The comparisons of the computed radiation patterns with measured data and results from the commercial software show that our method has good accuracy for slottedwaveguide array.Then the influence of mutual coupling between adjacent slotted-waveguides is studied.To demonstrate capability of the presented method,a carefully designed large X-band slotted-waveguide antenna array containing eighteen waveguides with Taylor amplitude and inverse phase excitation distribution are analyzed in the paper.

Aberrantly Methylated MGMT,hMLH1 and hMSH2 in Tumor and Serum DNA of Gliomas Patients

OBJECTIVE This study is to investigate the prevalence ofpromoter CpG island methylation of O^6-methylguananine-DNAmethyltransferase (MGMT), mismatch repair genes (hMLH1 andhMSH2) in both tumor and serum samples of gliomas.METHODS Methylation-specific PCR (MSP) was employed todetect promoter CpG island methylation of the MGMT, hMLH1and hMSH2 genes in 39 samples taken from surgery and 32samples of pretreatment serum all from the patients with gliomas.RESULTS Promoter CpG island methylation of MGMT, hMLH1and hMSH2 was detected and the results were 46.2%, 10.3% and20.5%, respectively in tumor DNA of the cases with gliomas,and 40.6%, 9.4% and 18.8%, respectively in serum DNA of thecases. The methylation pattern in primary tumor and serum wasfound to be concordant in matched tissue and serum samplesof 21 patients. In the cases with positive result of methylationfor MGMT, hMLH1 and hMSH2 in tumor tissues, the results ofdetection for those in the paired serum sample were 77.8% (7/9),66.7% (2/3) and 75.0 % (3/4), respectively. False positive resultswere not obtained in any of the patients who did not exhibitmethylation. No association was found between the promotermethylation of MGMT, hMLH1, and hMSH2 genes in primarygliomas and gender, age, localization, grade of malignant or tumorstage.CONCLUSION Promoter CpG island methylation is a frequentevent in gliomagenesis. Methylation analysis appears to bea promising predictive factor of the prognosis for the gliomapatients treated with alkylating drugs and a noninvasive tumormarker in serum DNA.

Effective Trace Acquirement during Product Information Diffusion and Application

Information dissemination has become part of people’s daily communication and there is great interest for both academic and industrial communities. Most previous studies have focused on the strategy and mechanisms. The methods controlling the process of information diffusion have rarely been studied. Thus, previous studies have failed to effectively mine the value of product information diffusion on social networks. In this study, based on the information diffusion product in consumer self-organized social networks, the control of the product information diffusion process was explored. The node identification principle of the QR code sender designed in this study and the linked list that associated information with specific nodes allowed the acquisition of effective traces in long-chain transmission from the information source to the value nodes, and solved user information disclosure during the transmission process. This method was applied to the tracing system of defective vehicles, achieving accurate recall of defective vehicles.

Anemoside B4 inhibits SARS-CoV-2 replication in vitro and in vivo

Objective: Anemoside B4(AB4), the most abundant triterpenoidal saponin isolated from Pulsatilla chinensis, inhibited influenza virus FM1 or Klebsiella pneumoniae-induced pneumonia. However, the anti-SARS-CoV-2 effect of AB4 has not been unraveled. Therefore, this study aimed to determine the antiviral activity and potential mechanism of AB4 in inhibiting human coronavirus SARS-CoV-2 in vivo and in vitro.Methods: The cytotoxicity of AB4 was evaluated using the Cell Counting Kit-8(CCK8) assay. SARS-CoV-2 infected HEK293T, HPAEpiC, and Vero E6 cells were used for in vitro assays. The antiviral effect of AB4 in vivo was evaluated by SARS-CoV-2-infected hACE2-IRES-luc transgenic mouse model. Furthermore,label-free quantitative proteomics and bioinformatic analysis were performed to explore the potential antiviral mechanism of action of AB4. Type Ⅰ IFN signaling-associated proteins were assessed using Western blotting or immumohistochemical staining.Results: The data showed that AB4 reduced the propagation of SARS-CoV-2 along with the decreased Nucleocapsid protein(N), Spike protein(S), and 3C-like protease(3CLpro) in HEK293T cells. In vivo antiviral activity data revealed that AB4 inhibited viral replication and relieved pneumonia in a SARS-CoV-2 infected mouse model. We further disclosed that the antiviral activity of AB4 was associated with the enhanced interferon(IFN)-β response via the activation of retinoic acid-inducible gene Ⅰ(RIG-1) like receptor(RLP) pathways. Additionally, label-free quantitative proteomic analyses discovered that 17 proteins were significantly altered by AB4 in the SARS-CoV-2 coronavirus infections cells. These proteins mainly clustered in RNA metabolism.Conclusion: Our results indicated that AB4 inhibited SARS-CoV-2 replication through the RLR pathways and moderated the RNA metabolism, suggesting that it would be a potential lead compound for the development of anti-SARS-CoV-2 drugs.

Notoginsenoside R1 Protects against Diabetic Nephropathy through TXNIP-NLRP3 Signaling Pathway

Background:Diabetic nephropathy(DN)is a microvascular complication of diabetes mellitus(DM).DN results from many factors,including changes in glomerular hemodynamics,oxidative stress and inflammation,and in-terstitial fibrosis and tubular atrophy.Panax notoginseng,a commonly used Chinese medicine,has been used in the treatment of kidney disease.Notoginsenoside R1(NGR1),the main compound isolated from P.notoginseng,has been reported to have a renoprotective role in DN.However,the therapeutic effect and mechanism of NGR1 in DN remain unclear.Objective:The present study aimed to investigate the therapeutic effect and mechanism of NGR1 in DN.Methods:In this study,mouse podocytes(MPC-5 cells)and db/db mice were used to investigate the effect of NGR1 on DN in vitro and in vivo,respectively.Blood glucose,renal function,inflammatory factors,and PI3K/AKT-Nrf2-NLRP3 signaling pathway proteins were assessed.Results:The study results indicated that NGR1 reversed cell viability induced by high glucose(HG,30 mM).The related mechanism results showed that NGR1 decreased oxidative stress by inhibiting reactive oxygen species(ROS)level and upregulating the expression of Nrf2,NQO1,and HO-1 via TXNIP targeting.In addition,NLRP3 inflammasome and PI3K/AKT were engaged in NGR1-based protection against HG-stimulated podocytes.In db/db mice,NGR1 significantly decreased blood glucose,urine protein,urine output,blood urea nitrogen,and other parameters as well as reversed kidney injury by inhibiting oxidative stress and proinflammatory response.Conclusion:Taken together,this study revealed that NGR1 exerted a significant therapeutic effect on DN both in vitro and in vivo via a mechanism related to the TXNIP-Nrf2 pathway and NLRP3 inflammasome,suggesting that NGR1 is a potential therapeutic option for DN.

Microstructure and Mechanical Properties of an Ultrahigh-strength Titanium alloy Ti-4.5Al-5Mo-5V-6Cr-1Nb Prepared Using Laser Directed Energy Deposition and Forging:A Comparative Study

The application of titanium alloys in aerospace put forward the requirement for higher strength.Additive manu-facturing is a promising method for the efficient and economical processing of titanium alloys.However,research on the additive manufacturing of ultrahigh-strength titanium alloys is still limited.The mechanisms of microseg-regation for high alloying elements and poor plasticity are still not clear.In this study,an ultrahigh-strength titanium alloy Ti-4.5Al-5Mo-5V-6Cr-1Nb(TB18)was prepared using two methods:laser direct energy deposi-tion(LDED)and forging.The LDEDed alloy contains three zones with similar grain morphologies but different microstructure.The microsegregation of the alloy is limited due to the rapid solidification and almost eliminated after the thermal cycle and solution treatment.With stress relief treatment,the LDEDed alloy exhibits anisotropic mechanical properties.After solution and aging treatments,its ultimate strength is enhanced;however,its plas-ticity is relatively lower than that of the wrought alloy with equally high strength.The excellent balance of the strength and plasticity of the wrought alloy can be ascribed to the formation of𝛼WGB and multiscale𝛼laths,which provides enlightenment for optimizing the properties of the LDEDed alloy.

Illumination Adaptive Identification Algorithm of a Reconfigurable Modular Robot

Reconfigurable modular robots feature high mobility due to their unconstrained connection manners.Inspired by the snake multi-joint crawling principle,a chain-type reconfigurable modular robot(CRMR)is designed,which could reassemble into various configurations through the compound joint motion.Moreover,an illumination adaptive modular robot identification(IAMRI)algorithm is proposed for CRMR.At first,an adaptive threshold is applied to detect oriented FAST features in the robot image.Then,the effective detection of features in non-uniform illumination areas is achieved through an optimized quadtree decomposition method.After matching features,an improved random sample consensus algorithm is employed to eliminate the mismatched features.Finally,the reconfigurable robot module is identified effectively through the perspective transformation.Compared with ORB,MA,Y-ORB,and S-ORB algorithms,the IAMRI algorithm has an improvement of over 11.6%in feature uniformity,and 13.7%in the comprehensive indicator,respectively.The IAMRI algorithm limits the relative error within 2.5 pixels,efficiently completing the CRMR identification under complex environmental changes.

腺嘌呤所致大鼠肾损伤的蛋白质组变化及其白头翁皂苷B4的调节作用（英文）

腺嘌呤常常用于制作慢性肾损伤及其肾间质纤维化的动物模型。除了炎性损伤之外,作为内源性物质的腺嘌呤对肾脏的损害尚未得到充分研究和阐明。为此,我们利用LC-MS/MS技术对腺嘌呤负荷后大鼠肾脏的蛋白质组学进行了分析,并观察了anemoside B4(B4)的作用。结果表明,腺嘌呤与正常组相比可以下调285个基因,上调大鼠肾组织中的164个基因。下调基因主要影响能量代谢的通路,而上调基因则影响炎症反应途径和其它一些代谢途径。B4可以显著逆转下调基因中的40个基因,这些基因涉及线粒体、氧化还原过程、细胞外外泌体、乙酰化和其他信号传导途径。同时,B4可明显抑制由腺嘌呤引起的6个上调基因,主要涉及细胞周期、卵母细胞减数分裂、PI3K-Akt等信号通路。使用实时定量PCR方法对其中一些基因进行mRNA表达,其结果也与蛋白质组学分析结果基本一致。因此可见,由腺嘌呤引起的大鼠肾损伤更复杂,不仅与炎症反应有关,而且对身体各种代谢过程有广泛影响。该工作为全面了解腺嘌呤诱导的肾损伤提供了有价值的线索。

Al-free cladding-layer blue laser diodes with a low aspect ratio in far-field beam pattern

c-plane GaN-based blue laser diodes(LDs) were fabricated with Al-free cladding layers(CLs) and deepened etching depth of mesa structure, so the aspect ratio of the far-field pattern(FFP) of the laser beam can be reduced to as low as 1.7, which is nearly the same as conventional AlGa In P-based red LDs. By using GaN CLs,the radiation angle of the laser beam θ⊥ is only 10.1° in the direction perpendicular to the junction plane. After forming a deeply etched mesa, the beam divergence angle parallel to the junction plane of FFP, θ_(//), increases from4.9° to 5.8°. After using the modified structure, the operation voltage of LD is effectively reduced by 2 V at an injection current of 50 mA, but the threshold current value increases. The etching damage may be one of the main reasons responsible for the increase of the threshold current.

Irrational-Behavior-Proof Conditions Based on Limit Characteristic Functions

Irrational-behavior-proof(IBP) conditions are important aspects to keep stable cooperation in dynamic cooperative games. In this paper, we focus on the establishment of IBP conditions.Firstly, the relations of three kinds of IBP conditions are described. An example is given to show that they may not hold, which could lead to the fail of cooperation. Then, based on a kind of limit characteristic function, all these conditions are proved to be true along the cooperative trajectory in a transformed cooperative game. It is surprising that these facts depend only upon the individual rationalities of players for the Shapley value and the group rationalities of players for the core. Finally,an illustrative example is given.

Integrating Krylov Deferred Correction and Generalized Finite Difference Methods for Dynamic Simulations of Wave Propagation Phenomena in Long-Time Intervals

In this paper,a high-accuracy numerical scheme is developed for long-time dynamic simulations of 2D and 3D wave propagation phenomena.In the derivation of the present approach,the second order time derivative of the physical quantity in the wave equation is treated as a substitution variable.Based on the temporal discretization with the Krylov deferred correction(KDC)technique,the original wave problem is then converted into the modified Helmholtz equation.The transformed boundary value problem(BVP)in space is efficiently simulated by using the meshless generalized finite difference method(GFDM)with Taylor series after truncating the second and fourth order approximations.The developed scheme is finally verified by four numerical experiments including cases with complicated domains or the temporally piecewise defined source function.Numerical results match with the analytical solutions and results by the COMSOL software,which demonstrates that the developed KDC-GFDM can allow large time-step sizes for wave propagation problems in longtime intervals.

3D printed on-chip microtoroid resonators and nested spiral photonic devices

An integrated polymer microtoroid resonator system fabricated using single-step,two-photon polymerization laser lithography is reported.The integrated microtoroid-waveguide system includes an integrated coupling waveguide for ease of optical coupling and has a quality factor of 16,000.We further demonstrate a nested doublespiral waveguide that allows higher spatial density of data,akin to a macroscopic form of space-division multiplexing.Experimental characterization reveals good transmission properties in the double-spiral waveguide device.In addition,the waveguides are demonstrated to support 30 Gb/s nonreturn-to-zero and 28 Gb/s pulse amplitude modulation 4 high-speed data.

GaN-based ultraviolet microdisk laser diode grown on Si

This work reports a demonstration of electrically injected GaN-based near-ultraviolet microdisk laser diodes with a lasing wavelength of 386.3 nm at room temperature. The crack-free laser structure was epitaxially grown on Si substrates using an Al-composed down-graded Al N/AlGaN multilayer buffer to mitigate the mismatches in the lattice constant and coefficient of thermal expansion, and processed into “sandwich-like” microdisk structures with a radius of 12 μm. Air-bridge electrodes were successfully fabricated to enable the device electrical characterization. The electrically pumped lasing of the as-fabricated microdisk laser diodes was evidenced by the rapid narrowing down of electroluminescence spectra and dramatic increase in the light output power, as the current exceeded the threshold of 248 mA.