[Dental pulp stem cells in tooth regeneration: advancement and emerging directions].

Regenerating tissues similar to dental structure with normal function are putatively to be the aim in tooth regeneration filed. Currently, researchers preliminarily achieved tooth regeneration by applying dental pulp stem cells (DPSC) and stem cells from human exfoliated deciduous teeth (SHED). However, the regeneration efficiency remains unstable and needs further investigation. The development of single-cell RNA sequencing and organoid culture system provide potential of precise, targeted and controllable functional regeneration. This article reviews the current state of DPSC/SHED on tooth regeneration, and analyzes characteristics and hotspots of them, aiming to shed light on clinical translational application of stable and efficient tooth regeneration.

[Investigation and analysis of late reporting and under-reporting of occupational diseases from 2018 to 2020 in China].

Objective: To understand the late reporting and the under-reporting of occupational disease from 2018 to 2020 in China and analyze the causes, so as to provide scientific evidence for improving the quality of occupational disease reports in China, timely acquiring the incidence of occupational disease, and assessing the occupational hazards. Methods: From May to December 2021, A total of 320 occupational disease diagnostic institutions were selected for investigation. The original documents of occupational disease diagnosis cases from 2018 to 2020 were compared with the online reported cases, and late reported and under-reported cases of occupational disease were analyzed. Results: A total of 32207 diagnosed cases from 2018 to 2020 were investigated, including 28934 confirmed cases and 3273 cases without occupational disease. The overall late reported rate and under-reported rate of confirmed cases were 20.2% and 2.1%, respectively. There were significant differences in the rate of late reporting and under-reporting of occupational diseases in different regions and different types of diagnostic institutions (P<0.001). The southwest region had the highest rates of late reporting and under-reporting, 61.6% and 7.9% respectively. The late reported rate of all kinds of occupational diseases was about 15.0%, and the under-reported rate was from 1.5.0% to 5.0%. Conclusion: At present, the phenomenon of late reporting and under-reporting occupational diseases is still obvious. It is necessary to strengthen the inspection of occupational disease reporting, improve the quality of occupational disease reporting, and provide scientific basis for the formulation of occupational disease prevention and control policies.

[A summary on surveillance system of occupational disease under the framework of National Health Insurance Informatization Project].

The surveillance of occupational disease has entered a new stage ofdevelopment, with the implementation of the national health informatization project. To improve the efficiency and quality of occupational disease monitoring information reporting in this paper, the system architecture and related management regulations, as long as the major changes and achievement of "surveillance system of occupational disease and health hazards information" under the framework of National Health Insurance Informatization Project were elaborated. The deficiencies existing in the system were analyzed, and expectation for the construction of the occupational disease surveillance system was addressed.

Space-efficient optical computing with an integrated chip diffractive neural network.

Large-scale, highly integrated and low-power-consuming hardware is becoming progressively more important for realizing optical neural networks (ONNs) capable of advanced optical computing. Traditional experimental implementations need N2 units such as Mach-Zehnder interferometers (MZIs) for an input dimension N to realize typical computing operations (convolutions and matrix multiplication), resulting in limited scalability and consuming excessive power. Here, we propose the integrated diffractive optical network for implementing parallel Fourier transforms, convolution operations and application-specific optical computing using two ultracompact diffractive cells (Fourier transform operation) and only N MZIs. The footprint and energy consumption scales linearly with the input data dimension, instead of the quadratic scaling in the traditional ONN framework. A ~10-fold reduction in both footprint and energy consumption, as well as equal high accuracy with previous MZI-based ONNs was experimentally achieved for computations performed on the MNIST and Fashion-MNIST datasets. The integrated diffractive optical network (IDNN) chip demonstrates a promising avenue towards scalable and low-power-consumption optical computational chips for optical-artificial-intelligence.

[Early histological changes detected by confocal microscopy in patients with advanced keratoconus receiving collagen cross-linking therapy].

Objective: To investigate the early histological changes by confocal microscopy of patients with advanced keratoconus receiving collagen cross-linking therapy. Methods: In this prospective case series study, confocal microscopy was used to observe 23 patients (32 eyes) who were diagnosed with advanced keratoconus and treated with collagen cross-linking at the Department of Ophthalmology, Chinese PLA General Hospital from September 2017 to March 2019, aged (26±10) year. All patients were examined before and at 1 week, 1 month and 3 months after the therapy. The tissue structure changes, the density of nerve fibers, stromal cells and endothelial cells, and the depth of the corneal stroma were recorded and compared. The overall differences at different times were compared by repeated measurement analysis of variance or Friedman test, and the pairwise comparison was corrected by LSD-t test or Bonferroni test. Results: One week after collagen cross-linking, the epithelial cells were in the repair stage, showing an increased nucleolar size and an enhanced reflection, and the activated cells could be detected under the epithelium. The superficial corneal stroma was swollen and spongiform, while the deep corneal stroma was patchy or cord-like, scattered and with a strong reflection. One month after the therapy, epithelial cells recovered, subepithelial nerves began to grow, the superficial corneal stroma still showed a spongy structure, and the reflection was further enhanced. The activation of the deep corneal stroma exhibited as thicker plaques or cord-like structure. Three months after the therapy, the continuous elongation of single nerve fibers could be detected occasionally. There was statistically significant difference in the density of nerve fibers before and early after the therapy (F=233.30, P<0.001). Compared with the preoperative value [(14.60±2.57) mm/mm2], the density of subepithelial nerve fibers decreased significantly in the early postoperative period, which was (0.51±0.31), (3.65±2.21) and (8.50± 4.02) mm/mm2, respectively, at 1 week, 1 month and 3 months, and there were significant differences between different time points (all P<0.05). There was also statistically significant differences in the density of anterior stromal cells before and early after the therapy (χ2=92.48, P<0.001). Compared with the preoperative value [347.00(345.00,395.75) cells/mm2] the density of anterior stromal cells decreased significantly in the early postoperative period, which was 2.00(1.00,5.75), 2.50(1.00,5.75) and 79.00(64.25,94.00) cells/mm2, respectively, at 1 week, 1 month and 3 months, and there were significant differences between different time points (all P<0.05). Within 3 months after the therapy, the depth of the corneal stroma observed by confocal microscopy ranged from 245 to 536 µm, with an average of (400.56±86.12) µm. Histologically, the depth of the corneal stroma ranged from 245 to 536 µm [average, (402.13±89.20) µm], from 251 to 527 µm [average, (399.88±85.92) µm] and from 259 to 530 µm [average, (399.69±85.94) µm] at 1 week, 1 month and 3 months, respectively, with no significant difference (F=0.797, P=0.455). There was no significant difference in the density of posterior stromal cells [(260.6±33.2) cells/mm2 preoperatively, (264.4±44.5) cells/mm2 at 1 week, (263.9±37.6) cells/mm2 at 1 month and (266.3±40.2) cells/mm2 at 3 months] and endothelial cells [(2 707±152.6) cells/mm2 preoperatively, (2 704±148.5) cells/mm2 at 1 week, (2 705±152.6) cells/mm2 at 1 month and (2 704±150.1) cells/mm2 at 3 months] between different time points (F=1.380, 1.011; P=0.259, 0.351). Conclusions: Confocal microscopy is able to clearly document the early morphological characteristics after collagen cross-linking in the treatment of keratoconus, including the epithelial and subepithelial nerve injury repair, the spongiform superficial corneal stroma, the patchy or cord-like deep corneal stroma, and the relatively stable stromal depth change.

An optical neural chip for implementing complex-valued neural network.

Complex-valued neural networks have many advantages over their real-valued counterparts. Conventional digital electronic computing platforms are incapable of executing truly complex-valued representations and operations. In contrast, optical computing platforms that encode information in both phase and magnitude can execute complex arithmetic by optical interference, offering significantly enhanced computational speed and energy efficiency. However, to date, most demonstrations of optical neural networks still only utilize conventional real-valued frameworks that are designed for digital computers, forfeiting many of the advantages of optical computing such as efficient complex-valued operations. In this article, we highlight an optical neural chip (ONC) that implements truly complex-valued neural networks. We benchmark the performance of our complex-valued ONC in four settings: simple Boolean tasks, species classification of an Iris dataset, classifying nonlinear datasets (Circle and Spiral), and handwriting recognition. Strong learning capabilities (i.e., high accuracy, fast convergence and the capability to construct nonlinear decision boundaries) are achieved by our complex-valued ONC compared to its real-valued counterpart.

[Advances in esophageal microbiota and esophageal related diseases].

Esophagus, as the pipe connecting oral cavity and stomach, has unique anatomical structure and physiological functions. The related diseases including esophageal cancer and precancerous lesions are the ones of major public health problems in China. The pathogenesis of esophageal diseases is still not clear. The exploration of correlation between the changes of esophageal microbiota and esophageal diseases becomes a new breakthrough in the study of etiology. Previous studies have found enrichment of gram-positive bacteria in the normal esophagus, while a decrease in diversity of bacteria and a dominant gram-negative anaerobe in diseased esophagus. Although much progress has been made in the study of esophageal microbiota, the standard method of how to accurately and noninvasively collect esophageal microbiota is still lack, which is an important part of the esophageal microbial research.

Microring resonator-assisted Fourier transform spectrometer with enhanced resolution and large bandwidth in single chip solution.

Single chip integrated spectrometers are critical to bring chemical and biological sensing, spectroscopy, and spectral imaging into robust, compact and cost-effective devices. Existing on-chip spectrometer approaches fail to realize both high resolution and broad band. Here we demonstrate a microring resonator-assisted Fourier-transform (RAFT) spectrometer, which is realized using a tunable Mach-Zehnder interferometer (MZI) cascaded with a tunable microring resonator (MRR) to enhance the resolution, integrated with a photodetector onto a single chip. The MRR boosts the resolution to 0.47 nm, far beyond the Rayleigh criterion of the tunable MZI-based Fourier-transform spectrometer. A single channel achieves large bandwidth of ~ 90 nm with low power consumption (35 mW for MRR and 1.8 W for MZI) at the expense of degraded signal-to-noise ratio due to time-multiplexing. Integrating a RAFT element array is envisaged to dramatically extend the bandwidth for spectral analytical applications such as chemical and biological sensing, spectroscopy, image spectrometry, etc.

Author Correction: Sculpting nanoparticle dynamics for single-bacteria-level screening and direct binding-efficiency measurement.

The original version of this Article omitted the author Kuan Wang, who is from the 'College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan' and 'Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore.'Also, the author S.H. Lim was incorrectly given as L.S. Hoi and A. Larsson was incorrectly given as A. Larson.The "Author contributions" was amended to reflect the authorship changes. It previously read 'Y.Z.S., C.-W.Q., and A.Q.L. jointly conceived the idea. Y.Z.S., S.X., Y.Z., J.B.Z., W.S., J.H.W., T.N.C., Z.C.Y., Y.L.H., B.L., P.H.Y., D.P.T., and C.-W.Q. performed the numerical simulations and theoretical analysis. Y.Z.S., S.X., and L.K.C. did the fabrication and experiments of particle hopping, biomolecule binding and flow cytometry. A.L. and L.S.H. did the SPR experiments. S.X., Y.Z.S., Y.Z., C.-W.Q., Y.-Y.C., L.K.C., T.H.Z., and A.Q.L. prepared the manuscript. S.X., Y.Z., C.-W.Q., and A.Q.L. supervised and coordinated all the work. All authors commented on the manuscript.' The correct version states 'B.L., K. W., P.H.Y.' instead of 'B.L., P.H.Y.' and 'S.H.L.' in place of 'L.S.H.'This has been corrected in both the PDF and HTML versions of the Article.

Intermittent lead-induced stress on antioxidant enzyme activity and subcellular distribution of Pb in Pogonatherum crinitum seedlings.

Pogonatherum crinitum is a promising lead (Pb) hyperaccumulator due to its high Pb tolerance and accumulation ability. However, the mechanisms that support Pb accumulation and tolerance in P. crinitum are not yet clearly understood. An indoor hydroponic experiment was conducted by cultivating P. crinitum seedlings exposed to intermittent Pb stress for 60 days, divided into four stages (T1, T2, T3 and T4), with a 15-day duration per stage. The following concentrations of Pb were used: 0, 500, 0, 500 mg·l-1 and 0, 1000, 0, 1000 mg·l-1 ). Antioxidant enzyme activity, Pb concentration and subcellular distribution of Pb were measured at each of the above stages. The results showed that superoxide dismutase (SOD) activity in shoots, and SOD, peroxidase (POD) and malondialdehyde (MDA) activity in shoots and roots significantly increased from T1 (no Pb stress) to T2 (Pb stress) in both 500 mg·l-1 and 1000 mg·l-1 treatments; however, no significant difference was noted between stages T3 (no Pb stress) and T4 (Pb stress). There was no obvious effect of Pb stress on catalase (CAT) activity in shoots and roots among different stages. The Pb concentration in shoots was up to 5090.90 mg·kg-1 and 7573.57 mg·kg-1 , and the bioconcentration factor (BFC) was 10.18 and 7.57 for the 500 mg·l-1 and 1000 mg·l-1 treatments, respectively, which confirmed the Pb hyperaccumulator characteristics of P. crinitum. For plants under Pb stress, most of the Pb was fixed in the cell walls, with a smaller amount in leaves and root vacuoles. Both SOD and POD scavenging of reactive oxygen radicals and fixing and compartmentalisation of Pb in the cell wall might play important roles in detoxification of P. crinitum seedlings in response to Pb stress. There was no phased response of P. crinitum to intermittent Pb stress and the physiological response to Pb stress may be contiguous.

Sculpting nanoparticle dynamics for single-bacteria-level screening and direct binding-efficiency measurement.

Particle trapping and binding in optical potential wells provide a versatile platform for various biomedical applications. However, implementation systems to study multi-particle contact interactions in an optical lattice remain rare. By configuring an optofluidic lattice, we demonstrate the precise control of particle interactions and functions such as controlling aggregation and multi-hopping. The mean residence time of a single particle is found considerably reduced from 7 s, as predicted by Kramer's theory, to 0.6 s, owing to the mechanical interactions among aggregated particles. The optofluidic lattice also enables single-bacteria-level screening of biological binding agents such as antibodies through particle-enabled bacteria hopping. The binding efficiency of antibodies could be determined directly, selectively, quantitatively and efficiently. This work enriches the fundamental mechanisms of particle kinetics and offers new possibilities for probing and utilising unprecedented biomolecule interactions at single-bacteria level.

[Changes of intestinal mucosal barrier in mice with chronic ulcerative colitis].

Objective: To study the damage and mechanism of intestinal mucosal barrier function in mice with ulcerative colitis induced by Dextran sulphate sodium (DSS). Methods: Mice models of chronic ulcerative colitis induced by DSS were established. The mice were completely randomized into normal control group and DSS group, 25 mice in each group. The body weight and colon length of the mice were monitored. The pathological examination of colon tissue was confirmed the success of the model and assessed the integrity of the colonic mucosal barrier; Evan's Blue's intestinal permeability analysis assessed the function of colon mucosal barrier; immunofluorescence staining and Western blot were used to evaluate the expression of intestinal mucosal barrier integrity-related proteins. Results: Compared with the normal control group, the DSS group had lower body weight [(25.6±0.7)g vs (23.5±0.7)g, t=2.14, P<0.05], and the colon length was shorter [(7.3±0.4)cm vs (5.6±0.2)cm, t=3.975, P<0.001]; colonic pathological results showed that the intestinal mucosa became thinner and part of the intestinal mucosa was defective; Evan's Blue instilled into the intestinal lumen was more abundant into the intestinal mucosa, and the optical density at 620 nm (OD(620))/colon tissue weight (g) was higher [(0.11±0.01) vs (0.15±0.01), t=4.174, P<0.05]; immunofluorescence and Western blot results showed lower expression of ZO-1, Claudin-1, and F-actin in colonic mucosa. Conclusion: The structure and function of intestinal mucosal barrier in DSS-induced chronic ulcerative colitis mice is impaired.

Tunable Polarization Conversion and Rotation based on a Reconfigurable Metasurface.

Polarization is an important property of electromagnetic (EM) wave and different polarization manipulations are required for varied optical applications. Here we report a reconfigurable metasurface which achieves both the polarization conversion and the polarization rotation in THz regime. The metasurface is reconfigured through the micro-electro-mechanical-systems (MEMS) actuation. The cross polarization transmittance from a linear polarized incidence is experimentally tuned from 0 to 28% at 2.66 THz. In addition, the polarization rotation angle is effectively changed from -12.8° to 13.1° at 1.78 THz. The tunable bi-functional metasurface for polarization conversion and the polarization rotation can be flexibly applied in various applications such as imaging, polarization microscopy and material analysis, etc.

Haemolysis during sodium dimercaptosulphonate therapy for Wilson's disease in G6PD-deficient patients: First report of two cases.

WHAT IS KNOWN AND OBJECTIVE: Wilson's disease (WD) is an inherited disorder in which defective biliary excretion of copper leads to its accumulation. Sodium dimercaptosulphonate (DMPS) is used as the primary therapy in China. CASE DESCRIPTION: We report two cases, with WD and G6PD deficiency, who developed haemolysis on treatment with DMPS, without any other known risk. After withdrawal of DMPS and administration of dexamethasone and packed red blood cells, the patients recovered. WHAT IS NEW AND CONCLUSION: Clinicians should keep in mind haemolysis as a potentially life-threatening side effect of DMPS in patients with G6PD.

High-resolution and multi-range particle separation by microscopic vibration in an optofluidic chip.

An optofluidic chip is demonstrated in experiments for high-resolution and multi-range particle separation through the optically-induced microscopic vibration effect, where nanoparticles are trapped in loosely overdamped optical potential wells created with combined optical and fluidic constraints. It is the first demonstration of separating single nanoparticles with diameters ranging from 60 to 100 nm with a resolution of 10 nm. Nanoparticles vibrate with an amplitude of 3-7 µm in the loosely overdamped potential wells in the microchannel. The proposed optofluidic device is capable of high-resolution particle separation at both nanoscale and microscale without reconfiguring the device. The separation of bacteria from other larger cells is accomplished using the same chip and operation conditions. The unique trapping mechanism and the superb performance in high-resolution and multi-range particle separation of the proposed optofluidic chip promise great potential for a diverse range of biomedical applications.

[Effects of cell-to-cell communication and histone acetyltransferase on the change of osteogenic differentiation ability among single-cell clones from healthy periodontium with heterogeneity of osteogenic differentiation abilities].

Objective: To investigate the effect of cell-to-cell communication amongst single-cell clones from healthy periodontium with different osteogenic differentiation potentials on change of osteogenic differentiation capabilities and the role histone acetyltransferase partaken in this process. Methods: In order to research the change of osteogenic differentiation ability via cell-to-cell communication, indirect co-culture method was used by placing two single-cell clones with different osteogenesis potentials in each of the 6-well plates. Blank control, weak and strong osteogenic groups were set up, corresponding to Transwell chambers with blank, cells of weak osteogenesis ability and cells of strong osteogenesis ability, respectively. Each group was made in triplicate. After co-culture for four days, Transwell chamber was removed. Quantitative real-time PCR (qPCR) and alizarin red staining were employed to detect the change of osteogenic differentiation ability. The acetylation level of H3 was measured by using Western blotting. Histone acetyltransferases were detected by qPCR. Results: Single-cell clones were ensured from mesenchymal stem cells by flow cytometer, the positive expression of CD29, CD90, CD105, CD146 was (99.80±0.02)%, (99.36±0.18)%, (99.41±0.05)% and (95.10±2.11)%, respectively. And CD31 and CD34 expression were (0.29±0.11)% and (0.22±0.13)%, respectively. Alizarin red and oil red O staining confirmed that single-cell clones had the abilities of adipogenesis and osteogenesis. Alkaline phosphatase (ALP) and alizarin red staining indicated that different single-cell clones were heterogeneity in osteogenesis differentiation. Indirect co-culture indicated that the mRNA expression of osteocalcin (OCN) were 14.24±5.60 and 4.78±2.90, respectively and Runt-related transcription factor 2 (RUNX2) were 2.75±1.44 and 1.61±0.44, respectively, in strong and weak osteogenic groups. They were significantly higher compared to the blank group (the mRNA expression of OCN and RUNX2 were 1.00±0.47 and 1.00±0.39, respectively). The expression of OCN and RUNX2 were also higher in strong osteogenic group than that in weak osteogenic group (P<0.05). The mean gray level of the acetylation of H3 in strong osteogenic group (0.76±0.09) and weak osteogenic group (0.54±0.12) were also higher than that in the blank group (0.30±0.04)(P<0.05). qPCR results showed that KAT6A in strong osteogenic group exhibiting higher expression (P<0.05) compared to weak osteogenic group and the blank group, which were corresponding to the changes of acetylation levels. Conclusions: Single-cell clones from healthy periodontium showed heterogeneity in osteogenic differentiation abilities. Single-cell clones with strong osteogenesis abilities had an advantage over others by promoting others' osteogenesis differentiation and this change mediated by cell-to-cell communication might be caused by modulating KAT6A to affect the acetylation level of histone.

20-Hydroxyecdysone stimulates nuclear accumulation of BmNep1, a nuclear ribosome biogenesis-related protein in the silkworm, Bombyx mori.

The pathway of communication between endocrine hormones and ribosome biogenesis critical for physiological adaptation is largely unknown. Nucleolar essential protein 1 (Nep1) is an essential gene for ribosome biogenesis and is functionally conserved in many in vertebrate and invertebrate species. In this study, we cloned Bombyx mori Nep1 (BmNep1) due to its high expression in silk glands of silkworms on day 3 of the fifth instar. We found that BmNep1 mRNA and protein levels were upregulated in silk glands during fourth-instar ecdysis and larval-pupal metamorphosis. By immunoprecipitation with the anti-BmNep1 antibody and liquid chromatography-tandem mass spectrometry analyses, it was shown that BmNep1 probably interacts with proteins related to ribosome structure formation. Immunohistochemistry, biochemical fractionation and immunocytochemistry revealed that BmNep1 is localized to the nuclei in Bombyx cells. Using BmN cells originally derived from ovaries, we demonstrated that 20-hydroxyecdysone (20E) induced BmNep1 expression and stimulated nuclear accumulation of BmNep1. Under physiological conditions, BmNep1 was also upregulated in ovaries during larval-pupal metamorphosis. Overall, our results indicate that the endocrine hormone 20E facilitates nuclear accumulation of BmNep1, which is involved in nuclear ribosome biogenesis in Bombyx.

Correction: Optofluidic lens with low spherical and low field curvature aberrations.

Correction for 'Optofluidic lens with low spherical and low field curvature aberrations' by H. T. Zhao et al., Lab Chip, 2016, 16, 1617-1624.