Fast reconstruction of laser beam near-field and focal spot profiles using deep neural network and numerical propagation.

Inertial confinement fusion (ICF) experiments demand precise knowledge of laser beam parameters on high-power laser facilities. Among these parameters, near-field and focal spot distributions are crucial for characterizing laser beam quality. While iterative phase retrieval shows promise for laser beam reconstruction, its utility is hindered by extensive iterative calculations. To address this limitation, we propose an online laser beam reconstruction method based on deep neural network. In this method, we utilize coherent modulation imaging (CMI) to obtain labels for training the neural network. The neural network reconstructs the complex near-field distribution, including amplitude and phase, directly from a defocused diffraction pattern without iteration. Subsequently, the focal spot distribution is obtained by propagating the established complex near-field distribution to the far-field. Proof-of-principle experiments validate the feasibility of our proposed method.

Mathematical uniqueness of multimode ptychographic imaging.

By writing diffracted intensities as a set of linear equations with the self-correlation of sample's Fourier components as unknown terms and the self-correlation of illumination's Fourier components as coefficients, it was found that the number of unknown terms to be determined is much larger in partially coherent PIE than that in purely coherent PIE. When a partially coherent illumination composed of N modes was applied a unique reconstruction can be determined by scanning the sample to at least 4N positions and recording 4N frames of diffraction patterns. While mathematically illustrating the physical mechanism of multimode ptychography and numerically demonstrating its capability in generating unique reconstruction under partially coherent illumination, this study showed for the first time that multimode ptychography could be an analytic imaging method.

Three-wavelength digital photoelasticity.

A three-wavelength photoelasticity method is proposed to simplify the optical setup and speed up data acquisition. By recording six intensity images with circularly polarized illuminations of three close wavelengths, the phase retardation and corresponding inner stress can be computed accurately with a correspondingly developed computational algorithm. Since the mechanical rotations of wave plates and polarizers required by classic photoelasticity techniques are avoided, the data acquisition of this proposed method is very speedy, and measurement of a dynamic sample can be achieved with a very simple and compact optical setup. Besides theoretical analyses, numerical and experimental evidences are also used to confirm the feasibility of this suggested three-wavelength digital photoelasticity method.

Dual-channel binary diffuser-based coherent modulation imaging.

To improve the performance of binary diffuser-based coherent modulation imaging (CMI), a double-channel optical alignment was proposed. Two diffraction patterns formed by the reflection and transmission of a binary diffuser were simultaneously captured and adopted for iterative reconstruction in combination. The information involved in reflected light, not considered in the traditional single-channel optical alignment, was also reconstructed in this dual-channel binary diffuser-based coherent modulation imaging (DB-CMI). The reconstruction quality and speed were improved and verified by both numerical simulations and proof-of-principle experiments. Therefore, DB-CMI improves traditional CMI and provides a powerful tool for quantitative phase imaging.

sPhaseStation: a whole slide quantitative phase imaging system based on dual-view transport of intensity phase microscopy.

Whole slide imaging scans a microscope slide into a high-resolution digital image, and it paves the way from pathology to digital diagnostics. However, most of them rely on bright-field and fluorescence imaging with sample labels. In this work, we designed sPhaseStation, which is a dual-view transport of intensity phase microscopy-based whole slide quantitative phase imaging system for label-free samples. sPhaseStation relies on a compact microscopic system with two imaging recorders that can capture both under and over-focus images. Combined with the field of view (FoV) scan, a series of these defocus images in different FoVs can be captured and stitched into two FoV-extended under and over-focus ones, which are used for phase retrieval via solving the transport of intensity equation. Using a 10× micro-objective, sPhaseStation reaches the spatial resolution of 2.19 µm and obtains the phase with high accuracy. Additionally, it acquires a whole slide image of a 3m m×3m m region in 2 min. The reported sPhaseStation could be a prototype of the whole slide quantitative phase imaging device, which may provide a new perspective for digital pathology.

Single-shot measurement of the near-field and focal spot profiles of a 351 nm laser beam for SGII-upgraded facility with multiple-focal-plane constraint coherent modulation imaging.

Inertial confinement fusion (ICF) places an urgent demand for precise measurement of 351 nm (3ω) laser beam parameters when performing physical experiments on high-power laser facilities. The near-field and focal spot distributions are the utmost important parameters to characterize the quality of the laser beam. Coherent modulation imaging (CMI) is a promising technique for online laser beam measurement, however, it fails to reconstruct the near-field and focal spot profiles when it is used to measure the beam quality of a 351 nm laser beam for SGII-upgrade facility. To solve this problem, a novel CMI reconstruction algorithm is proposed in this work, and the performance of the algorithm in 3ω laser beam measurement can be obviously improved. By adopting multiple-virtual-focal-plane constraint in the proposed algorithm, the near-field and focal spot profiles of the 3ω laser beam can be successfully reconstructed. Experiments have been conducted on SGII-upgrade facility to verify the feasibility of the proposed method.

Safety and efficacy of telitacicept in refractory childhood-onset systemic lupus erythematosus: A self-controlled before-after trial.

OBJECTIVE: To observe the efficacy and safety of telitacicept in refractory childhood-onset systemic lupus erythematosus (cSLE). METHODS: A self-controlled before-after trial. Children with active SLE, aged 5-18 years, who cannot tolerate side effects of glucocorticoid, were enrolled in our study. Patients received subcutaneous injection of telitacicept weekly based on the standard treatment. SLE responder index-4 (SRI-4) was assessed before the first administration and at least 4 weeks after the first administration. RESULTS: Among the 15 cases of refractory cSLE, three were males (20%) and 12 were females (80%). The median age and weight were 13 years old and 52 kg, respectively. The median duration of disease was 30 months. 5-26 weeks (80 or 160 mg per week) after administration of telitacicept, 66.7% (n=10) reached SRI-4 response. 12 cases reduced their glucocorticoid intake from 40 mg/d to 17.5 mg/d. The urinary protein after treatment declined in 8 cases whose 24-h proteinuria was >0.5 g at baseline. The urinary protein in two of the eight cases turned negative and plasma albumin in five of the eight cases rose to normal. In addition, three of these eight cases demonstrated varying degrees of improvement in renal impairment, whose estimated glomerular filtration rate (eGFR, ml/min·1.73 m2) rose from 17.4 to 26.6, 40.7 to 48.2, and 63.2 to 146.0, respectively. There were mild to moderate adverse events after treatment. CONCLUSION: Telitacicept combined with the standard treatment may significantly increase the SRI-4 response rate and reduce the glucocorticoid dosage in refractory cSLE, and also shown efficacy on lupus nephritis. The related adverse drug events were controllable.

Cloning, expression, purification, and biochemical characterization of CpxR protein from pectobacterium carotovorum.

The cpxR gene, encoding a new cytoplasmic response regulator, which effects virulence, biofilm formation, chemotaxis, resistance to antimicrobials, and controls soft rot, was amplified by the polymerase chain reaction, cloned into the prokaryotic expression vector pET-15b, and expressed through the induction of isopropyl-ß-d-thiogalactoside in Escherichia coli BL21 (DE3). Then, highly purified and stable CpxR protein was produced by nickel affinity chromatography and fast protein liquid chromatography, digested by thrombin and identified by Western blotting. Furthermore, the structure of the CpxR protein was estimated by circular dichroism spectroscopy and SWISS-MODEL. The CpxR protein was a functional part in signal transduction and bacterial resistance for Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The resear ch of the protein stability indicated the CpxR protein had excellent thermal stability and was suitable for crystallization. Then the small crystals of CpxR protein were found in the crystallizing tank. The latest 34 cpxR sequences from the public database were selected and analyzed by molecular clustering and multisequence alignment. These cpxR sequences were roughly divided into four categories. These results laid an important foundation for the further structural study of the CpxR protein.

Resolution enhancement with highly curved illumination in ptychography.

By deducing a formula to compute a sample from recorded diffraction intensity directly and analytically, the relationship among the highest reachable resolution of the ptychographic iterative engine (PIE), its illumination angle, and its collection angle was discussed analytically. Curved illumination was then proposed to realize the resolution enhancement for PIE, and a corresponding computing algorithm was proposed to avoid an undersampling effect without increasing the size of the computing matrix, thus realizing speedy high-resolution PIE imaging with a simple experimental setup. While theoretical analysis was carried out, the feasibility of this proposed method was verified both numerically and experimentally.

Laser-pulse-induced temperature, thermal stress, and crater morphology effect during multipulse nanosecond laser manufacturing.

We construct a numerical model for multipulse laser drilling. It is found that the previous laser-pulse-induced temperature accumulation, thermal stress occurrence, and crater morphology change promote subsequent pulse laser drilling. Among them, previous laser-pulse-induced temperature accumulation contributes significantly to the drilled crater depth when the workpiece temperature is higher than its melting point just before the subsequent laser pulse irradiation, especially in a short pulse interval condition. The crater morphology change becomes the main contributor when the workpiece temperature decreases below the melting point, often in a long pulse interval condition. Besides, the previous occurrence of laser-pulse-induced thermal stress always has had little influence on the drilled crater. This work can be a theoretical reference, especially for multipulse laser manufacturing.

Whole genome sequencing and comparative genomics analysis of Pectobacterium carotovorum identifies key pathogenic genes.

Based on Single moleculereal time(SMRT)sequencing technology, the high-quality whole genome sequence of Pectobacterium carotovorum (PC1) was obtained by the PacBio RS II sequencer. The genome is a single circular chromosome of 5.3 Mb in size, containing three kinds of m6A methylation modification by SMRT Portal analysis. Genome annotation showed that 575 virulence factor genes, 304 drug resistance genes, 774 pathogen genes, 7 secretory systems and 22 pairs of two-component regulatory system could be relevant to bacterial pathogenicity. In addition, the average nucleotide identities (ANI) analysisshowed that the PC1 exhibited the highest homology with the Pectobacteriumcarotovorumsubsp.carotovorumstrain BP201601.1 (NZ_CP034236). There are 28 unique gene families to PC1 using cluster analysis of gene families. According to the analysis of key pathogenic genes, we have obtained three kinds of highly conserved genes related to cell wall degrading enzymes, including 19 pectinase genes, 25 cellulase genes and 22 protease genes. Our studies have provided a theoretical basis for investigation of bacterial soft rot and biological specific bactercides of PC1.

Multiple interference theoretical model for graphene metamaterial-based tunable broadband terahertz linear polarization converter design and optimization.

Terahertz (THz) polarization converters often working as modulators and switches have many applications in THz sensing, imaging and communication, but many of them still suffer from low polarization conversion efficiency, fixed and narrow polarization conversion band, and low output polarization purity, which are mainly due to the lack of theoretical model for THz polarization converter design and optimization. In order to solve the problem, we adopt multiple interference theory to successfully design and optimize a graphene metamaterial-based tunable broadband THz linear polarization converter: it achieves polarization conversion ratio (PCR) over 0.97, polarization azimuth angle of almost ±90° and rather low ellipticity within a broad polarization conversion band of 1.25 THz; and additionally, its polarization conversion band can be actively tuned by adjusting the graphene chemical potential and almost insensitive to the incident THz radiation angle below 50°. Considering the high performance of the optimal graphene metamaterial-based tunable broadband THz linear polarization converter, this work provides an optimal design offering a way in high-quality manipulation of THz radiation polarization; but more importantly, delivers a theoretical model for tunable THz polarization converter design and optimization.

REPAID: resolution-enhanced plenoptic all-in-focus imaging using deep neural networks.

Due to limited depth-of-focus, classical 2D images inevitably lose details of targets out of depth-of-focus, while all-in-focus images break through the limit by fusing multi-focus images, thus being able to focus on targets in extended depth-of-view. However, conventional methods can hardly obtain dynamic all-in-focus imaging in both high spatial and temporal resolutions. To solve this problem, we design REPAID, meaning resolution-enhanced plenoptic all-in-focus imaging using deep neural networks. In REPAID, multi-focus images are first reconstructed from a single-shot plenoptic image, then upsampled using specially designed deep neural networks suitable for real scenes without ground truth to finally generate all-in-focus image in both high temporal and spatial resolutions. Experiments on both static and dynamic scenes have proved that REPAID can obtain high-quality all-in-focus imaging when using simple setups only; therefore, it is a promising tool in applications especially intended for imaging dynamic targets in large depth-of-view.

[A case of SIFD syndrome caused by novel compound heterozygous variants of TRNT1 gene].

OBJECTIVE: To detect variant of TRNT1 gene in a child featuring sideroblastic anemia with B-cell immunodeficiency, periodic fever and developmental delay (SIFD). METHODS: The proband and his parents were analyzed through trio-whole exome sequencing. Sanger sequencing and bioinformatic analysis were carried out to verify the candidate variant sites associated with the clinical phenotype. RESULTS: Genetic testing showed that the proband has carried compound heterozygous variants of the TRNT1 gene, namely c.88A>G(p.Met30Val) and c.363G>T(p.Glu121Asp). Sanger sequencing confirmed that the variants were respectively inherited from his father and mother. The variants were unreported previously. By bioinformatic analysis, both variants were predicted to affect the stability of binding of the TRNT1 protein with tRNA. Based on the American College of Medical Genetics and Genomics standards and guidelines, c.88A>G and c.363G>T variants of TRNT1 gene were predicted to be uncertain significance (PM2+PP3+PP4) and likely pathogenic (PM1+PM2+PP3+PP4), respectively. CONCLUSION: The c.88A>G (p.Met30Val) and c.363G>T(p.Glu121Asp) compound heterozygous variants of the TRNT1 gene probably underlay the disease in this patient. Above finding has enriched the spectrum of TRNT1 gene variants.

High-speed coherent diffraction imaging by varying curvature of illumination with a focus tunable lens.

A high-speed coherent diffraction imaging method is proposed by varying the curvature of illumination with a focus tunable lens. The imaging setup is free of conventional mechanical translation and takes only milliseconds to refocus by changing the electric signal applied on the lens. It is more compact and also an inexpensive alternative to coherent diffraction imaging with computerized translational stages. A detector that is kept at a fixed distance from the sample records diffraction patterns each time the spherical wavefront illuminations on the sample is changed with a control current. The complex wavefront of the object is then quantitatively recovered from the diffraction intensity measurements using an iterative phase retrieval algorithm. The feasibility of the proposed method is experimentally verified using various samples. Extremely short response time of the focus tunable lens makes the proposed method highly suitable for applications that requires high speed imaging.

Programmable liquid crystal display based noise reduced dynamic synthetic coded aperture imaging camera (NoRDS-CAIC).

Besides traditional lens-based imaging techniques, coded aperture imaging (CAI) can also provide target images but without using any optical lenses, therefore it is another solution in imaging applications. Most CAI methods reconstruct target image only from a single-shot coded image using a fixed coding mask; however, the collected partial information inevitably deteriorates the reconstruction quality. Though multi-exposure CAI methods are designed, these existed algorithms can hardly improve reconstruction signal-to-noise ratio (SNR) and spatial resolution simultaneously; additionally, dynamic coding mask display still requires expensive devices and complicated systems. In order to reconstruct target image with both enhanced spatial resolution and SNR but using cost-effective devices and a simple system, we design a noise reduced dynamic synthetic coded aperture imaging camera (NoRDS-CAIC) in this paper. The NoRDS-CAIC only consists of a programmable liquid crystal display (LCD) and an image recorder, and both of them are integrated with a three-dimensional printed shell with the compact size of 19 cm × 15 cm × 16 cm and controlled by our designed software to automatically realize coding mask display, coded image recording and target image reconstruction. When using the NoRDS-CAIC, the optimized coding mask is first sent to the programmable LCD and displayed, then the corresponding coded image is automatically captured using the image recorder. Next, cycle the above procedures to capture enough coded images with previously known coding masks and measured point spread functions (PSFs), and the target image can be finally reconstructed using our designed NoRDS-CAIC decoding algorithm, which is shown with better noise suppression capability and higher reconstruction resolution compared to other classical CAI algorithms. According to the experimental verifications, the NoRDS-CAIC can reach the high resolution of 99.2 µm and the high SNR of 19.43 dB, proving that the designed NoRDS-CAIC can be potentially used for lensless imaging in practical applications.

Optical multi-image encryption based on focal length multiplexing and multimode phase retrieval.

A novel optical multi-image encryption method based on focal length multiplexing and multimode phase retrieval is proposed in this study. During the encryption process of the proposed method, multiple secret images were encrypted into a single intensity-only image using focal length multiplexing and a coherent diffractive imaging-based encryption system. A specially designed iterative algorithm based on multimode phase retrieval is proposed for the accurate decryption of the original multiple secret images from the intensity pattern. The advantages of the proposed method include a compact optical setup and high decryption quality. The feasibility, security, and robustness of the proposed method were investigated by numerical simulations.

Single-shot optical multiple-image encryption by jointly using wavelength multiplexing and position multiplexing.

A single shot large-capacity optical multiple-image encryption method based on wavelength multiplexing and position multiplexing is proposed. In the encryption process of the proposed method, multiple plane waves of different wavelengths are adopted to illuminate secret images that are placed at different positions along the optical axis. All the secret images are encoded into a single grayscale intensity-only image that is recorded by a monochromic camera by applying a diffractive-imaging based double random phase encoding (DRPE) system. In the decryption process, high accuracy images are decrypted without crosstalk from the intensity image through a multimode phase retrieval algorithm and a two-step iterative shrinkage/thresholding (TwIST) algorithm. The feasibility of the proposed method is demonstrated by numerical simulations.

Speckle-illuminated Fourier ptychography: analysis of diffuser roughness and reconstruction aperture on imaging performance.

With a fundamentally modified structural illumination algorithm, the recently proposed speckle-illuminated Fourier ptychography can be a promising superresolution imaging technique with a large field of view. However, its imaging performance, including image resolution and signal-to-noise ratio, has been discussed less, limiting its further applications. Thus, an in-depth study of this new imaging technique is highly required. In this paper, with theoretical analysis, numerical simulations, and experiments, the influence of both diffuser roughness in the experimental setup and numerical aperture size in iterative reconstruction on the imaging performance of speckle-illuminated Fourier ptychography was studied in detail, and the result explained why a rougher diffuser and larger reconstruction aperture can generate a higher-resolution image with more noise and showed how to get optimized diffuser roughness and reconstruction aperture size by considering the trade-off between imaging resolution and signal-to-noise ratio. This work may be a good reference for high-quality imaging using speckle-illuminated Fourier ptychography.

Single-shot aperture-scanning Fourier ptychography.

Aperture-scanning Fourier ptychography [Opt. Express22, 13586 (2014)] is a promising non-interferometric wavefront measurement technique. It eliminates the thin-sample requirement in typical Fourier ptychography employing angle-varying illumination. However, as aperture-scanning Fourier ptychography is based on step-by-step scanning, it requires long data acquisition time and a high-stability optical system. In this paper, we propose a single-shot aperture-scanning Fourier ptychography method. In our method, multiple low-resolution images are collected in a single shot by inserting a Dammann grating at a certain distance before the aperture, and the images are subsequently converted to a high-resolution complex wavefront. Compared with scanning-based aperture-scanning Fourier ptychography, the total acquisition time of the proposed method is dramatically reduced. The feasibility of our proposed method is demonstrated by proof-of-concept experiments.