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Self‐luminous projection technologies, such as Micro‐LED chips, compared with traditional projection methods, does not require complex lighting path. So it can significantly improve light utilization rate and reduce costs. However, technical challenges in Micro‐LED chip production make it difficult to improve the chip's resolution further. Some studies have shown that compared with the original image resolution of the spatial light modulator (SLM), the projection images overlapped is an effective method to improve the resolution of the projector. In this paper, we study the working principle of the extended pixel resolution actuator and propose a self‐luminous projection resolution enhancement system based on Micro‐LED chip. It can improve the resolution of the projection images with the resolution of the Micro‐LED chip unchanged. The resolution enhancement system consists of a Micro‐LED chip, an extended pixel resolution actuator and a projection lens. According to the working principle of the extended pixel resolution actuator, the projection lens is an image‐space telecentric structure, in which modulation transfer function of projection imaging at Nyquist frequency 100 lp/mm is greater than 0.4. Finally, the tolerance analysis on the projection lens is completed. The results show that the projection lens has a high success rate in processing. This work is of great significance for improving the resolution of Micro‐LED self‐luminous projection images. [ABSTRACT FROM AUTHOR]

Digital watermarking technology is an important security protection technology for secret communication and content authentication. To better realize the copyright protection of color images, this paper proposes three large-capacity watermark embedding schemes based on the prime number distribution theory. In the process of watermark embedding, the three channels of R, G, and B of the color carrier image are separated, and according to the division of the prime number set within 0-255, through three different pixel replacement principles, the color image of 256 × 256 can be realized at one time. Embed three binary watermark images of the same size, and the watermark embedding capacity is 24567 bit. The experimental results show that the PSNR values of the three schemes are all greater than 40dB, and the NC values are all close to 1. In addition to the sizeable embedding capacity, the scheme proposed in this paper can resist common image processing attacks while ensuring good watermark imperceptibility and has good tamper detection and localization capabilities. [ABSTRACT FROM AUTHOR]

The edge elasticity and its effect on flexoelectric response of the Janus MoSSe nanoribbons are systematically explored by means of density functional theory based first-principles calculations. We report edge stresses, edge elastic moduli, and structural deformations of the Janus MoSSe nanoribbons with various widths. It is shown that both armchair and zigzag terminated edges of the MoSSe nanoribbons are essentially subjected to tension, due to the existence of the edge stresses. The magnitude of average zigzag edge stresses is much larger than that of the average armchair ones. Furthermore, our results show that both misfit strain induced by asymmetric chalcogen atomic layers, and the edge stresses cause the spontaneous bending deformation of such Janus nanoribbons. More importantly, flexoelectronic properties of semiconducting armchair MoSSe nanoribbons are carefully evaluated and compared with those of armchair MoS 2 and MoSTe nanoribbons. In particular, it is found that the out-of-plane flexoelectronic coefficients strongly depend on their widths. Additionally, the flexoelectric response resulting from spontaneous bending is weaker than that from the opposite one. The implicit mechanisms on deformations and flexoelectronic properties of such Janus nanoribbons have been carefully explored. The results in this work provide useful insights into their potential applications in nanoscale electromechanical systems. [ABSTRACT FROM AUTHOR]

Introduction: There was limited evidence on the quality of reporting and methodological quality of prediction models using machine learning methods in preterm birth. This systematic review aimed to assess the reporting quality and risk of bias of a machine learning‐based prediction model in preterm birth. Material and methods: We conducted a systematic review, searching the PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, China Biology Medicine disk, VIP Database, and WanFang Data from inception to September 27, 2021. Studies that developed (validated) a prediction model using machine learning methods in preterm birth were included. We used the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) statement and Prediction model Risk of Bias Assessment Tool (PROBAST) to evaluate the reporting quality and the risk of bias of included studies, respectively. Findings were summarized using descriptive statistics and visual plots. The protocol was registered in PROSPERO (no. CRD 42022301623). Results: Twenty‐nine studies met the inclusion criteria, with 24 development‐only studies and 5 development‐with‐validation studies. Overall, TRIPOD adherence per study ranged from 17% to 79%, with a median adherence of 49%. The reporting of title, abstract, blinding of predictors, sample size justification, explanation of model, and model performance were mostly poor, with TRIPOD adherence ranging from 4% to 17%. For all included studies, 79% had a high overall risk of bias, and 21% had an unclear overall risk of bias. The analysis domain was most commonly rated as high risk of bias in included studies, mainly as a result of small effective sample size, selection of predictors based on univariable analysis, and lack of calibration evaluation. Conclusions: Reporting and methodological quality of machine learning‐based prediction models in preterm birth were poor. It is urgent to improve the design, conduct, and reporting of such studies to boost the application of machine learning‐based prediction models in preterm birth in clinical practice. [ABSTRACT FROM AUTHOR]

Genomic imprinting is essential for mammalian development. PGC7, an important maternal factor, binds to dimethylated histone H3K9 (H3K9me2), maintaining DNA methylation in zygotes and stem cells. However, the underlying molecular mechanisms of PGC7-maintained genomic imprinting in stem cells are not clear. Our previous study has identified that PGC7 interacts with HP1BP3, a novel member of the histone H1 family. In this study, we found that PGC7 interacts with the central globular domain of HP1BP3 through its C-terminal tail and that HP1BP3 is responsible for the recruitment of PGC7 at the Meg3 differentially methylated region (DMR) in the Dlk1-Dio3 imprinted domain. HP1BP3 or PGC7 depletion decreases enrichment in the Meg3-DMR, leading to DNA hypermethylation in this region. Moreover, the cooperative binding of PGC7 and HP1BP3 can antagonize the enrichment of DNMT3A in the Meg3-DMR, and the depletion of HP1BP3 or PGC7 separately induces chromosome decondensation in this region. In summary, this is the first study demonstrating that PGC7 and HP1BP3 synergistically maintain the methylation status of the Meg3-DMR by enabling a chromatin configuration that interferes with the binding of the de novo DNA methyltransferase DNMT3A., (© 2024 Wiley Periodicals LLC.)

Primordial germ cell 7 (PGC7)(Dppa3 or Stella) is a small inherently disordered protein that is mainly expressed in oocytes and plays a vital role in the regulation of DNA methylation reprogramming in imprinted loci through interaction with other proteins. Most of PGC7-deficient zygotes are blocked at two-cell stage with an increased tri-methylation at lysine 27 of histone H3 (H3K27me3) level in the nucleus. Our previous work has indicated that PGC7 interacts with yin-yang1 (YY1) that is essential for the recruitment of enhancer of zeste homolog 2 (EZH2)-containing Polycomb repressive complex 2 (PRC2) to H3K27me3 modification sites. Here, we found that the presence of PGC7 weakened the interaction between YY1 and PRC2 without disrupting the assembly of core subunits of the PRC2 complex. In addition, PGC7 promoted AKT to phosphorylate serine 21 of EZH2, resulting in inhibition of EZH2 activity and the dissociation of EZH2 from YY1, thereby decreasing H3K27me3 level. In zygotes, the PGC7-deficient and AKT inhibitor MK2206 both promoted EZH2 to enter the pronuclei but without disturbing the subcellular localization of YY1 and caused an increase in the level of H3K27me3 in the pronuclei, as well as inhibition of the expression of zygote-activating genes regulated by H3K27me3 in two-cell embryos. In summary, PGC7 could affect zygotic genome activation during early embryonic development by regulating the level of H3K27me3 through regulation of PRC2 recruitment, EZH2 activity, and subcellular localization. NEW & NOTEWORTHY PGC7 and YY1 interaction inhibits recruitment of PRC2 by YY1. PGC7 promotes AKT and EZH2 interaction to increase pEZH2-S21 level, which weakens YY1 and EZH2 interaction, thereby decreasing H3K27me3 level. In zygotes, the PGC7-deficient and AKT inhibitor MK2206 promote EZH2 to enter the pronuclei, and increase H3K27me3 level in the pronuclei, as well as inhibition of the expression of zygote-activating genes regulated by H3K27me3 in two-cell embryos, which ultimately affects early embryo development.