An experiment demonstrating single-pixel single-arm complementary compressive microscopic ghost imaging based on a digital micromirror device (DMD) has been performed. To solve the difficulty of projecting speckles or modulated light patterns onto tiny biological objects, we instead focus the microscopic image onto the DMD. With this system, we have successfully obtained a magnified image of micron-sized objects illuminated by the microscope's own incandescent lamp. The image quality of our scheme is more than an order of magnitude better than that obtained by conventional compressed sensing with the same total sampling rate, and moreover, the system is robust against intensity instabilities of the light source and may be used under very weak light conditions. Since only one reflection direction of the DMD is used, the other reflection arm is left open for future infrared light sampling. This represents a big step forward toward the practical application of compressive microscopic ghost imaging in the biological and material science fields. * gjzhai@nssc.ac.cn

We present an experimental demonstration of edge detection based on ghost imaging (GI) in the gradient domain. Through modification of a random light field, gradient GI (GGI) can directly give the edge of an object without needing the original image. As edges of real objects are usually sparser than the original objects, the signal-to-noise ratio (SNR) of the edge detection result will be dramatically enhanced, especially for large-area, high-transmittance objects. In this study, we experimentally perform one- and two-dimensional edge detection with a double-slit based on GI and GGI. The use of GGI improves the SNR significantly in both cases. Gray-scale objects are also studied by the use of simulation. The special advantages of GI will make the edge detection based on GGI be valuable in real applications.

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Purpose Ultra‐high dose rate FLASH irradiation (FLASH‐IR) has been shown to cause less normal tissue damage compared with conventional irradiation (CONV‐IR), this is known as the “FLASH effect.” It has attracted immense research interest because its underlying mechanism is scarcely known. The purpose of this study was to determine whether FLASH‐IR and CONV‐IR induce differential inflammatory cytokine expression using a modified clinical linac. Materials and methods An Elekta Synergy linac was used to deliver 6 MeV CONV‐IR and modified to deliver FLASH‐IR. Female FvB mice were randomly assigned to three different groups: a non‐irradiated control, CONV‐IR, or FLASH‐IR. The FLASH‐IR beam was produced by single pulses repeated manually with a 20‐s interval (Strategy 1), or single‐trigger multiple pulses with a 10 ms interval (Strategy 2). Mice were immobilized in the prone position in a custom‐designed applicator with Gafchromic films positioned under the body. The prescribed doses for the mice were 6 to 18 Gy and verified using Gafchromic films. Cytokine expression of three pro‐inflammatory cytokines (tumor necrosis factor‐α [TNF‐α], interferon‐γ [IFN‐γ], interleukin‐6 [IL‐6]) and one anti‐inflammatory cytokine (IL‐10) in serum samples and skin tissue were examined within 1 month post‐IR. Results The modified linac delivered radiation at an intra‐pulse dose rate of around 1 × 106 Gy/s and a dose per pulse over 2 Gy at a source‐to‐surface distance (SSD) of 13 to 15 cm. The achieved dose coverage was 90%–105% of the maximum dose within −20 to 20 mm in the X direction and 95% within −30 to 30 mm in the Y direction. The absolute deviations between the prescribed dose and the actual dose were 2.21%, 6.04%, 2.09%, and 2.73% for 6, 9, 12, and 15 Gy as measured by EBT3 films, respectively; and 4.00%, 4.49%, and 2.30% for 10, 14, and 18 Gy as measured by the EBT XD films, respectively. The reductions in the CONV‐IR versus the FLASH‐IR group were 4.89%, 10.28%, −7.8%, and −22.17% for TNF‐α, IFN‐γ, IL‐6, and IL‐10 in the serum on D6, respectively; 37.26%, 67.16%, 56.68%, and −18.95% in the serum on D31, respectively; and 62.67%, 35.65%, 37.75%, and −12.20% for TNF‐α, IFN‐γ, IL‐6, and IL‐10 in the skin tissue, respectively. Conclusions Ultra‐high dose rate electron FLASH caused lower pro‐inflammatory cytokine levels in serum and skin tissue which might mediate differential tissue damage between FLASH‐IR and CONV‐IR.