Ultra-broadband TM-pass polarizer based on anisotropic metamaterials in lithium niobate on an insulator.

An ultra-broadband TM-pass polarizer is designed, fabricated, and experimentally demonstrated based on subwavelength grating (SWG) metamaterials in a lithium niobate on an insulator (LNOI) platform. According to our simulation, the designed device is predicted to work at a 220 nm wavelength range from 1460 to 1680 nm, covering the S-, C-, L-, U-bands of optical fiber communication. By depositing and subsequently etching a silicon nitride thin film atop the LNOI chip, the SWG structures are formed successfully by using complementary metal-oxide semiconductor (CMOS)-compatible fabrication processes. The measured results show a high polarization extinction ratio larger than 20 dB and a relatively low insertion loss below 2.5 dB over a 130 nm wavelength range from 1500 to 1630 nm, mainly limited by the operation bandwidth of our laser source.

2D absolute position measurement based on the hybrid encoding method.

This paper introduces a new method of absolute position measurement based on the hybrid encoding principle that can precisely measure the absolute position of a two-dimensional (2D) micro displacement table. The method uses pseudo-random sequences and binary codes to generate the long-distance position encoding sequences. It combines the encoding sequences with checkerboards to form a hybrid encoding to complete the design of the 2D encoding of plane positions. Then a 2D encoding disk is designed as a tool to measure 2D absolute position. Among them, the X and Y positions are designed by the modular approach, respectively, to efficiently detect the accuracy of 2D position values during the measurement. Moreover, the designed 2D encoding disk can quickly realize image correction. In order to verify the feasibility of the designed 2D encoding disk for measuring the 2D absolute position, the corresponding measurement system is built using a 2D encoding disk, a CCD camera, and a telecentric lens. The experimental results demonstrate that the average position deviation of the 2D absolute position measurement system is less than ±1 µm.

An optical method based auto-collimation for measuring five degrees of freedom error motions of rotary axis.

The paper presents an optical method based on auto-collimation to simultaneously measure five degrees of freedom error motions of the rotary axis. The proposed method consists of the collimated lasers, beam splitters, focusing lens, quadrant photodiode detectors, a high-precision steel ball, and a special mirror fixed to the rotary axis. The mathematical model is established byoptical ray tracing, and the corresponding optical path is also simulated by OpticStudio. Meanwhile, an adjusting mechanism for X-Y micro-displacement, based on the elastic deformation of the material, is designed to adjust the installation eccentricity error of the high-precision steel ball. The calibration results of the proposed system demonstrate that the displacement errors are ±0.25 µm within the measuring range of ±10 µm, and the tilt angle errors are ±0.6 arcsec within the measuring range of ±25 arcsec. Taking a direct drive (DD) motor as the test object, the radial error motions of the rotary axis range from -3.2 to 4.1 µm, the axial error motions range from -4.9 to 4.7 µm, and the tilt error motions around the X and Y axes range from -2.8 to 1.8 arcsec and -2.6 to 2.0 arcsec, respectively.

Shikonin as a WT1 Inhibitor Promotes Promyeloid Leukemia Cell Differentiation.

This study aims to observe the differentiating effect of shikonin on Wilms' tumor 1 (WT1)-positive HL-60 cells and investigate the fate of the differentiated leukemia cells. WT1 overexpression unaffected cell viability but promoted resistance to H2O2-induced DNA injury and cell apoptosis. The binding of shikonin to the WT1 protein was confirmed by molecular docking and drug affinity reaction target stability (DARTS). Shikonin at the non-cytotoxic concentration could decrease the WT1 protein and simultaneously reduced the CD34 protein and increased the CD11b protein in a dose-dependent manner in normal HL-60 cells but not in WT1-overexpressed HL-60 cells. Shikonin unaffected HL-60 cell viability in 48 h. However, it lasted for 10 days; could attenuate cell proliferation, mitochondrial membrane potential (MMP), and self-renewal; prevent the cell cycle; promote cell apoptosis. In a mouse leukemia model, shikonin could decrease the WT1 protein to prevent leukemia development in a dose-dependent manner. In this study, we also confirmed preliminarily the protein-protein interactions between WT1 and CD34 in molecular docking and CO-IP assay. Our results suggest that: 1. shikonin can down-regulate the WT1 protein level for leukemia differentiation therapy, and 2. the interaction between WT1 and CD34 proteins may be responsible for granulocyte/monocyte immaturity in HL-60 cells.

Method for improving the measurement accuracy of binocular stereo vision in a scattering environment.

In the scattering environment, binocular stereo vision measurement technology produces large errors due to the change of refractive index of the imaging light path and the decrease in target image contrast. To address this problem, this paper proposes a method for improving the measurement accuracy of binocular stereo vision in a scattering environment combined with polarization imaging theory. First, scattering images with different polarization directions are obtained and filtered by a Gaussian low-pass filter to calculate the degree of polarization and angle of polarization. Then, the scattered light intensity is calculated by using polarization information to obtain images after removing the scattering. Second, feature extraction and matching are carried out for the images after scattering removal. Finally, the target is measured based on the binocular stereo vision measurement model. The experimental results show that when the scattering concentration is high enough, the conventional method can no longer perform measurement, but the method proposed in this paper can still obtain the target parameters at this time, and can also improve measurement accuracy by at least 46.30%. In conclusion, the proposed method provides a valuable reference to improve the accuracy of binocular stereo vision measurement in a scattering environment by reducing the interference of scattering light.

A 4.8 ps root-mean-square resolution time-to-digital converter implemented in a 20 nm Cyclone-10 GX field-programmable gate array.

It is difficult to improve the resolution and precision of a field-programmable gate array (FPGA)-based time-to-digital converter (TDC) in time interval measurement. In this study, we design a carry-look-ahead delay chain structure and integrate an interleaved sampling method with an online calibration and bin readjustment approach to implement a TDC. We take advantage of the adaptive logic module units applied in a Cyclone-10 GX (10CX220YF780E5G), which is a 20 nm low-power consumption and low-cost FPGA. In this new generation FPGA, we implemented a high-precision time interval measurement, which exceeded all our previous works with a 4.8 ps root-mean-square resolution and a 5.68 ps least-significant-bit resolution.

Integrating network pharmacology and transcriptomic validation to investigate the efficacy and mechanism of Mufangji decoction preventing lung cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Mufangji decoction (MFJD), a famous traditional Chinese medicine formula in Synopsis of Golden Chamber (Jingui yaolue), has been utilized to treat cough and asthma and release chest pain over 2000 years in China. Chinese old herbalist doctor use MFJD to treat lung cancer and cancerous pleural fluid, but the preventive effect of MFJD on lung cancer and the underlying mechanism are indefinite. AIM OF THE STUDY: The goal of this study is to explore the efficacy and mechanism of Mufangji decoction preventing lung cancer referring to the traditional use. MATERIALS AND METHODS: Tumor allograft experiment and host versus tumor experiment were used to observe the direct anti-tumor effect and indirect anti-tumor immune effect, the mouse lung carcinogenic model was used to evaluate the dose-response and the preventive effect of MFJD on lung cancer. The active ingredients of MFJD were obtained by UPLC-MS/MS. The potential targets of MFJD were screened by network pharmacology and transcriptomics. The therapeutic targets and pathways of MFJD on lung cancer were obtained by protein-protein interaction, molecular docking and David database. The predicted results were verified in vitro and in vivo. RESULTS: MFJD could significantly prevent tumor growth in host versus tumor experiment but could not in tumor allograft experiment, indicating an anti-tumor immune effect against lung cancer. MFJD could reduce lung nodules with a dose-response in mouse lung carcinogenic model. Myeloperoxidase (MPO) was selected as the core target due to the highest degree value in Protein-Protein interaction network and had potently binding activity to sinomenine and dehydrocostus lactone in molecular docking. In vivo, MPO-expressed neutrophils are negatively correlated with lung cancer progression and MFJD could promote the neutrophil-related immune surveillance. In vitro, sinomenine and dehydrocostus lactone could promote neutrophil phagocytosis, MPO and ROS production in a dose dependent manner. The major compounds from MFJD were identified to regulate 36 targets for lung cancer prevention by UPLC-MS/MS, network pharmacology and transcriptomics. David database exhibited that MFJD plays an important role in immunoregulation by modulating 4 immune-related biological processes and 3 immune-related pathways. CONCLUSIONS: MFJD prevents lung cancer by mainly promoting MPO expression to maintain neutrophil immune surveillance, its key compounds are sinomenine and dehydrocostus lactone.

Berberine regulates PADI4-related macrophage function to prevent lung cancer.

Coptis chinensis Franch (CCF) has been widely used by Chinese old herbalist doctor to treat internal and external diseases including malignant sore and cancer. Berberine (BBR) is a major bioactive compound in CCF and may exert anti-tumor and anti-inflammatory effects like CCF. However, the prevention effect of berberine against lung cancer and its relevance of anti-inflammation property to cancer-preventing effect are still obscure. Protein arginine deaminase 4 (PAD4) played an important role in macrophage related inflammatory response, the purpose of this study was to identify whether berberine can prevent lung cancer and explore its effect on PADI4-related macrophage function. In vitro, PADI4 overexpression affects cell-activated state in macrophages. PADI4 overexpressed macrophages promote epithelial-mesenchymal transition (EMT) of A549 lung cancer cells and inhibit cell apoptosis. Berberine at the experiment dose had no effect on cell viability of U937-derived macrophages, but could significantly inhibit PADI4 expression to reverse the macrophage-activated state and the lung cancer -promoting effect of PADI4-overexpressed macrophages. Unlike GSK484, berberine had a little effect on the PADI4 citrullination activity at the experimental doses, its IC50 for PADI4 inhibition is 45.07 µM (44.03-46.12 µM). In the mouse lung carcinogenetic model, PADI4 expression was directly related to the number of lung nodules. Berberine had the similar role to GSK484 in reducing the number of lung tumor nodules with the improved lung pathology in a dose-dependent manner and significantly inhibited PADI4 expression. Further, we found that PADI4 overexpression could inhibit IRF5 expression, up-regulate CD163 and CD206 and down-regulate CD86 in macrophages, which could be reversed by berberine. Our results suggest that berberine may regulate PADI4-related macrophage function to prevent lung cancer.

Resonant-type piezoelectric inertial drive mechanism with asymmetric inertial masses.

Resonant-type piezoelectric impact motors can improve the output capability effectively. A new construction of asymmetric inertial masses is proposed to synthesize approximate saw-tooth wave resonant vibration with matched anti-phase and in-phase modes. A prototype is designed, manufactured, and tested. With 40 Vp-p, 400 Hz exciting voltage for the anti-phase mode and 16 Vp-p, 800 Hz exciting voltage for the in-phase mode, the prototype provides a maximum no-load velocity of 17.2 mm/s and a maximum output power of 0.72 mW with 100 mN load. The velocity and output power of the prototype in the proposed resonant state are near three orders of magnitude higher than those in the traditional quasi-static state.

Absolute Positioning Accuracy Improvement in an Industrial Robot.

The absolute positioning accuracy of a robot is an important specification that determines its performance, but it is affected by several error sources. Typical calibration methods only consider kinematic errors and neglect complex non-kinematic errors, thus limiting the absolute positioning accuracy. To further improve the absolute positioning accuracy, we propose an artificial neural network optimized by the differential evolution algorithm. Specifically, the structure and parameters of the network are iteratively updated by differential evolution to improve both accuracy and efficiency. Then, the absolute positioning deviation caused by kinematic and non-kinematic errors is compensated using the trained network. To verify the performance of the proposed network, the simulations and experiments are conducted using a six-degree-of-freedom robot and a laser tracker. The robot average positioning accuracy improved from 0.8497 mm before calibration to 0.0490 mm. The results demonstrate the substantial improvement in the absolute positioning accuracy achieved by the proposed network on an industrial robot.

A 6.6 ps RMS resolution time-to-digital converter using interleaved sampling method in a 28 nm FPGA.

Based on the adaptive logic module structure implemented in a 28 nm field programmable gate array (FPGA), we propose an interleaved sampling method, together with bin realignment operation, to enable time-to-digital converter (TDC) implementation. The tap status is sampled twice in a single physical channel, meaning that TDC precision beyond the cell delay limit can be anticipated. Two TDC channels were implemented in a 28 nm Cyclone-V FPGA, and the effectiveness of the proposed method was evaluated. After calibration, the TDC produced a timing resolution of 6.6 ps root mean square or 5.8 ps per least significant bit.

A Compact Impact Rotary Motor Based on a Piezoelectric Tube Actuator with Helical Interdigitated Electrodes.

This paper presents a novel impact rotary motor based on a piezoelectric tube actuator with helical interdigitated electrodes which has a compact structure and high resolution. The assembled prototype motor has a maximum diameter of 15 mm and a length of 65 mm and works under a saw-shaped driving voltage. The LuGre friction model is adopted to analyze the rotary motion process of the motor in the dynamic simulations. From the experimental tests, the first torsional resonant frequency of the piezoelectric tube is 59.289 kHz with a free boundary condition. A series of experiments about the stepping characteristics of different driving voltages, duty cycles, and working frequencies are carried out by a laser Doppler vibrometer based on a fabricated prototype motor. The experimental results show that the prototype rotary motor can produce a maximum torsional angle of about 0.03° using a driving voltage of 480 Vp-p (peak-to-peak driving voltage) with a duty ratio of 0% under a small friction force of about 0.1 N. The motor can produce a maximum average angle of about 2.55 rad/s and a stall torque of 0.4 mN∙m at 8 kHz using a driving voltage of 640 Vp-p with a duty ratio of 0% under a large friction force of about 3.6 N. The prototype can be driven in forward and backward motion and is working in stick-slip mode at low frequencies and slip-slip mode at high frequencies.

An 18-ps TDC using timing adjustment and bin realignment methods in a Cyclone-IV FPGA.

The method commonly used to produce a field-programmable gate array (FPGA)-based time-to-digital converter (TDC) creates a tapped delay line (TDL) for time interpolation to yield high time precision. We conduct timing adjustment and bin realignment to implement a TDC in the Altera Cyclone-IV FPGA. The former tunes the carry look-up table (LUT) cell delay by changing the LUT's function through low-level primitives according to timing analysis results, while the latter realigns bins according to the timing result obtained by timing adjustment so as to create a uniform TDL with bins of equivalent width. The differential nonlinearity and time resolution can be improved by realigning the bins. After calibration, the TDC has a 18 ps root-mean-square timing resolution and a 45 ps least-significant bit resolution.

Sub-pixel projector calibration method for fringe projection profilometry.

Digital projectors are used as standard parts at present in fringe projection profilometry systems to project structured-light patterns onto the object surface to be measured, and the distortion of the projector lens must be calibrated and compensated accurately to satisfy the accuracy requirement of industrial applications. A novel method is proposed to determine the projector pixel coordinates of the marker points of a calibration target accurately in terms of projective transform. With the method, the projector can be calibrated with accuracy of sub-pixel level. The method is applicable for the calibration target with a chessboard pattern or a circle pattern, and the calibration result is independent on the results of camera calibration. Experimental results are shown to demonstrate the effectiveness and validity of the proposed method.