Differential Acoustic Resonance Spectroscopy for the acoustic measurement of small and irregular samples in the low frequency range
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
Authors: Wang, Shang-xu; Zhao, Jian-guo; Li, Zhen-hua; Harris, Jerry M.; Quan, Youli
Abstract
Differential Acoustic Resonance Spectroscopy (DARS) has been developed to investigate the acoustic properties of samples in the kilohertz frequency range. This new laboratory measurement technique examines the change in resonant frequencies of a cavity perturbed by the introduction of a small test sample. The resonant frequency shift between the empty and sample-loaded cavity is used to estimate the acoustic properties of the loaded sample. This paper presents a DARS perturbation formula that combines a theoretical derivation with numerical simulation and laboratory measurements. Furthermore, a semi-empirical calibration technique is proposed to estimate the acoustic properties of a test sample. This research demonstrates the potential of the DARS measurement technique for estimating the acoustic properties of acoustically small and/or irregularly shaped samples.
Oncogenic Long Noncoding RNA DARS-AS1 in Childhood Acute Myeloid Leukemia by Binding to microRNA-425
TECHNOLOGY IN CANCER RESEARCH & TREATMENT
Authors: Dou, Binghua; Jiang, Zhu; Chen, Xiaoguang; Wang, Chunmei; Wu, Jing; An, Jindou; Sheng, Guangyao
Abstract
Objective: Acute myeloid leukemia (AML) represents a hematological cancer. The aim of the investigation was to probe the regulatory relevance of long non-coding RNA (lncRNA) aspartyl-tRNA synthetase anti-sense 1 (DARS-AS1)/microRNA-425 (miR-425)/transforming growth factor-beta 1 (TGFB1) to the development of AML. Methods: The DARS-AS1 expression in bone marrow tissues was first analyzed in healthy subjects and AML patients. Subsequently, AML cell lines with DARS-AS1 knockdown were constructed, followed by cell proliferation and apoptosis assays. Afterward, downstream miRNA of DARS-AS1 and target mRNA of the miRNA were analyzed by bioinformatics, and their binding relationships were verified. Functional rescue experiments were then implemented. Finally, activation of the Smad2/3 signaling in MV4-11 and BF-24 cells were detected by western blot. Results: DARS-AS1 was overexpressed in bone marrow tissues of AML patients and cells, and DARS-AS1 knockdown suppressed the proliferation of AML cells and induced apoptosis. DARS-AS1 bound to and negatively correlated with miR-425. Further results suggested that TGFB1 might be a target gene of miR-425 and could promote Smad2/3 phosphorylation and nuclear translocation. Finally, DARS-AS1 depletion could diminish the tumor volumein vivo. Conclusion: All in all, we highlighted here that DARS-AS1 enhanced the expression of TGFB1 through binding to miR-425 to modulate AML progression via the Smad2/3 pathway, which might perform as a therapeutic target for AML.