In digital holographic microscopy, shot noise is an intrinsic part of the recording process with the digital camera. We present a study based on simulations and real measurements describing the shot-noise influence in the quality of the reconstructed phase images. Different configurations of the reference wave and the object wave intensities will be discussed, illustrating the detection limit and the coherent amplification of the object wave. The signal-to-noise ratio (SNR) calculation of the reconstructed phase images based on the decision statistical theory is derived from a model for image quality estimation proposed by Wagner and Brown [Phys. Med. Biol. 30, 489 (1985)]. It will be shown that a phase image with a SNR above 10 can be obtained with a mean intensity lower than 10 photons per pixel and per hologram coming from the observed object. Experimental measurements on a glass-chrome probe will be presented to illustrate the main results of the simulations.
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http://dx.doi.org/10.1364/ao.45.007667 | DOI Listing |
Whole-body PET imaging is often hindered by respiratory motion during acquisition, causing significant degradation in the quality of reconstructed activity images. An additional challenge in PET/CT imaging arises from the respiratory phase mismatch between CT-based attenuation correction and PET acquisition, leading to attenuation artifacts. To address these issues, we propose two new, purely data-driven methods for the joint estimation of activity, attenuation, and motion in respiratory self-gated TOF PET.
View Article and Find Full Text PDFWhile the genetic paradigm of cancer etiology has proven powerful, it remains incomplete as evidenced by the widening spectrum of non-cancer cell-autonomous "hallmarks" of cancer. Studies have demonstrated the commonplace presence of high oncogenic mutational burdens in homeostatically-stable epithelia. Hence, the presence of driver mutations alone does not result in cancer.
View Article and Find Full Text PDFSmall
January 2025
Faculty of Materials Science and Engineering, Analysis and Testing Research Center, Kunming University of Science and Technology, Kunming, 650093, P. R. China.
Modulating electronic structure to balance the requirement of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for developing bifunctional catalysts. Herein, phase transformation engineering is utilized to separately regulate catalyst structure, and the designed NiFe@Ni/Fe-MnOOH schottky heterojunction exhibits remarkable bifunctional electrocatalytic activity with low overpotentials of 19 and 230 mV at 10 mA cm for HER and OER in 1M KOH, respectively. Meanwhile, an anion-exchange membrane water electrolyzer employing NiFe@Ni/Fe-MnOOH as electrodes shows low voltages of 1.
View Article and Find Full Text PDFArch Esp Urol
December 2024
Polytechnic University of Coimbra, 3045-093 Coimbra, Portugal.
Penile cancer (PeCa) ranks as the 30th most prevalent cancer globally, predominantly affecting populations in developing countries. Phimosis and Human Papillomavirus (HPV) infection are recognized as the primary risk factors. Early-stage diagnosis typically warrants limited excision or non-invasive therapies.
View Article and Find Full Text PDFPLoS One
January 2025
Cnooc Information Technology Co., Ltd., Shenzhen, Guangdong, China.
A data transmission delay compensation algorithm for an interactive communication network of an offshore oil field operation scene in severe weather is proposed. To solve the problem of unstable microwave signals and a large amount of noise in the communication network caused by bad weather, the communication network signal denoising method based on Lagrange multiplier symplectic singular value mode decomposition is adopted, and the communication network data denoising process is realized through five steps; phase space reconstruction, symplectic geometric similarity transformation, grouping, diagonal averaging, and adaptive reconstruction. Simultaneously, the weak communication signal is compensated after being captured, that is, the characteristics of the weak signal are enhanced.
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