This study aims to ensure the effectiveness of medical ultrasound diagnostic equipment in clinical applications by testing multiple key performance indicators using tissue-mimicking phantoms and exploring the changes in these performance indicators over time. Firstly, 17 in-service medical ultrasound diagnostic equipments were selected, and their depth of penetration, dead zone, lateral resolution, axial resolution, geometric position error, and cystic focal diameter error were tested according to the verification regulations. In addition, the study retrospectively analyzed the performance testing data of 19 medical ultrasound diagnostic equipments over the past three consecutive years and conducted statistical analysis. Through the testing, all performance indicators of the 17 equipments met the requirements of the verification regulations, indicating that they can stably and reliably provide high-quality ultrasound diagnostic images and data in clinical applications. Meanwhile, retrospective data showed that with the increase with the increase in service life, the resolving ability at the far field of the 19 equipments decreased, and the cystic focal diameter error increased. Therefore, it is recommended that medical institutions establish a regular testing and maintenance system for medical ultrasound diagnostic equipment, conducting regular performance evaluations and maintenance to ensure its good working condition.
Phantoms, Imaging ; Ultrasonography/instrumentation* ; Retrospective Studies

MicroRNAs are endogenously expressed non-coding RNAs, which are composed of approximately 18 nucleotides to 25 nucleotides. Mature microRNAs regulate gene expression by base pairing with the 3'-untranslated region of target mRNAs. These mature microRNAs can degrade target mRNAs or inhibit translation. This process is a type of post-transcriptional regulation of gene ex-pression. Studies have shown that microRNAs are important in physiological and pathological processes, such as cell proliferation, cell differentiation, and cell death. This article provides an overview of the function of microRNAs in the regulation of macrophages.