Staring X-ray backscatter imaging based on ultra-high aspect ratio lobster eye lens: erratum.

An erratum to correct a mistake for the article titled "Staring X-ray backscatter imaging based on ultra-high aspect ratio lobster eye lens" published in Opt. Express32(7), 11600 (2024)10.1364/OE.514941. The corrections have no influence on the results and conclusions of the original paper.

Staring X-ray backscatter imaging based on ultra-high aspect ratio lobster eye lens.

In contrast to conventional X-ray imaging systems, the lobster eye lens, serving as a pivotal component for X-ray focusing, presents the potential for downsizing X-ray backscatter imaging systems. This study reports the successful implementation of a pioneering non-contact staring X-ray backscatter imaging experiment, with the target positioned 1.5 meters away from the system and employing a tube voltage of 60 kV for the X-ray light source. The system is built upon a novel high aspect ratio (500) meridian lobster eye lens, employing a laboratory low illuminance desktop light source and a commercial X-ray detector to achieve high-resolution focused imaging of hard X-rays. Point spread function testing and a series of imaging experiments were carried out to assess the resolution and optimal imaging photon energy of the proposed system. Furthermore, according to the characteristics of the point spread function of the cross image of the lobster eye lens, we proposed an image processing algorithm. The experimental results demonstrate that, after processing, the Structural Similarity (SSIM) Index of the backscatter image and the ground truth image can be improved from an average of 0.0526 to 0.5758. Our research significantly contributes to the advancement of a new generation of X-ray backscatter imaging systems.

Structural design method of the meridional lobster-eye lens with optimal efficiency.

Lobster-eye optics has been proposed as a high-energy detection device with great potential for astronomical observation and safety inspection due to its large-field-of-view (FOV) focusing ability. In this paper, we study the relationship between the optimal structural parameters of the meridional lobster-eye lens and focusing efficiency. The maximum odd-reflection component, which relates only to the FOV and the channel ratio of depth to width, has been found. Furthermore, the structural constant C, which determines the optimal efficiency structure of the meridional lobster-eye lens, is revealed for hard x-rays. Meanwhile, by introducing accurate reflectivity of iridium in soft x-rays, the constraint of the effective FOV with respect to x-ray wavelength is analyzed. The research results can help to design the optimal structure of the lobster-eye lens in multiple spectra.

Enhanced cell growth and tumorigenicity of rat glioma cells by stable expression of human CD133 through multiple molecular actions.

CD133 (Prominin-1/AC133) is generally treated as a cell surface marker found on multipotent stem cells and tumor stem-like cells, and its biological function remains debated. Genetically modified rat glioma cell lines were generated by lentiviral gene delivery of human CD133 into rat C6 glioma cells (hCD133(+) -C6) or by infection of C6 cells with control lentivirus (mock-C6). Stable hCD133 expression promoted the self-renewal ability of C6-formed spheres with an increase in the expression of the stemness markers, Bmi-1 and SOX2. Akt phosphorylation, Notch-1 activation, and Notch-1 target gene expression (Hes-1, Hey1 and Hey2) were increased in hCD133(+) -C6 when compared to mock-C6. The inhibition of Akt phosphorylation, Notch-1 activation, and Hes-1 in hCD133(+) -C6 cells effectively suppressed their clonogenic ability, indicating that these factors are involved in expanding the growth of hCD133(+) -C6. An elevated expression of GTPase-activating protein 27 (Arhgap27) was detected in hCD133(+) -C6. A decline in the invasion of hCD133(+) -C6 by knockdown of Arhgap27 expression indicated the critical role of Arhgap27 in promoting cell migration of hCD133(+) -C6. In vivo study further showed that hCD133(+) -C6 formed aggressive tumors in vivo compared to mock-C6. Exposure of hCD133(+) -C6 to arsenic trioxide not only reduced Akt phosphorylation, Notch-1 activation and Hes-1 expression in vitro, but also inhibited their tumorigenicity in vivo. The results show that C6 glioma cells with stable hCD133 expression enhanced their stemness properties with increased Notch-1/Hes-1 signaling, Akt activation, and Arhgap27 action, which contribute to increased cell proliferation and migration of hCD133(+) -C6 in vitro, as well as progressive tumor formation in vivo.