Collaborative Mobile-Learning Systems for Music Education and Training

Ph.DDOCTOR OF PHILOSOPH

Thoracic low-dose CT image processing using an artifact suppressed large-scale nonlocal means.

International audienceThe x-ray exposure to patients has become a major concern in computed tomography (CT) and minimizing the radiation exposure has been one of the major efforts in the CT field. Due to plenty high-attenuation tissues in the human chest, under low-dose scan protocols, thoracic low-dose CT (LDCT) images tend to be severely degraded by excessive mottled noise and non-stationary streak artifacts. Their removal is rather a challenging task because the streak artifacts with directional prominence are often hard to discriminate from the attenuation information of normal tissues. This paper describes a two-step processing scheme called 'artifact suppressed large-scale nonlocal means' for suppressing both noise and artifacts in thoracic LDCT images. Specific scale and direction properties were exploited to discriminate the noise and artifacts from image structures. Parallel implementation has been introduced to speed up the whole processing by more than 100 times. Phantom and patient CT images were both acquired for evaluation purpose. Comparative qualitative and quantitative analyses were both performed that allows conclusion on the efficacy of our method in improving thoracic LDCT data

Farm-waste-derived recyclable photothermal evaporator

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tian, Y., Liu, X., Li, J., Deng, Y., DeGiorgis, J. A., Zhou, S., Caratenuto, A., Minus, M. L., Wan, Y., Xiao, G., & Zheng, Y. Farm-waste-derived recyclable photothermal evaporator. Cell Reports Physical Science, 2(9), (2021): 100549, https://doi.org/10.1016./j.xcrp.2021.100549Interfacial solar steam generation is emerging as a promising technique for efficient desalination. Although increasing efforts have been made, challenges exist for achieving a balance among a plethora of performance indicators—for example, rapid evaporation, durability, low-cost deployment, and salt rejection. Here, we demonstrate that carbonized manure can convert 98% of sunlight into heat, and the strong capillarity of porous carbon fibers networks pumps sufficient water to evaporation interfaces. Salt diffusion within microchannels enables quick salt drainage to the bulk seawater to prevent salt accumulation. With these advantages, this biomass-derived evaporator is demonstrated to feature a high evaporation rate of 2.81 kg m−2 h−1 under 1 sun with broad robustness to acidity and alkalinity. These advantages, together with facial deployment, offer an approach for converting farm waste to energy with high efficiency and easy implementation, which is particularly well suited for developing regions.This project is supported by the National Science Foundation through grant no. CBET-1941743. This project is based upon work supported in part by the National Science Foundation under EPSCoR Cooperative Agreement no. OIA-1655221

PANDORA-seq expands the repertoire of regulatory small RNAs by overcoming RNA modifications

Although high-throughput RNA sequencing (RNA-seq) has greatly advanced small non-coding RNA (sncRNA) discovery, the currently widely used complementary DNA library construction protocol generates biased sequencing results. This is partially due to RNA modifications that interfere with adapter ligation and reverse transcription processes, which prevent the detection of sncRNAs bearing these modifications. Here, we present PANDORA-seq (panoramic RNA display by overcoming RNA modification aborted sequencing), employing a combinatorial enzymatic treatment to remove key RNA modifications that block adapter ligation and reverse transcription. PANDORA-seq identified abundant modified sncRNAs—mostly transfer RNA-derived small RNAs (tsRNAs) and ribosomal RNA-derived small RNAs (rsRNAs)—that were previously undetected, exhibiting tissue-specific expression across mouse brain, liver, spleen and sperm, as well as cell-specific expression across embryonic stem cells (ESCs) and HeLa cells. Using PANDORA-seq, we revealed unprecedented landscapes of microRNA, tsRNA and rsRNA dynamics during the generation of induced pluripotent stem cells. Importantly, tsRNAs and rsRNAs that are downregulated during somatic cell reprogramming impact cellular translation in ESCs, suggesting a role in lineage differentiation

Intelligent Suppression Method for Ionospheric Clutter Based on Clustering and Greedy Strategy

Clutter is a term used for unwanted echoes in electronic systems, particularly in reference to radars. Such echoes are typically returned from ground, sea, rain, animals/insects, chaff, and atmospheric turbulences, and can cause serious performance issues with radar systems. Ionospheric clutter is a time-varying, nonstationary, and non-Gaussian complex clutter in High-Frequency Surface-Wave Radar (HFSWR) system and its suppression is a daunting task. Extensive research on intelligent classification systems and suppression techniques of ionospheric clutter was conducted to solve the universal problem of single clutter suppression algorithm. After a complete analysis of the characteristics of ionospheric clutter, the present work proposes an intelligent ionospheric clutter processing method based on clustering and greedy algorithms for the classification and suppression of ionospheric clutter. Experimental results showed that the proposed method has a better performance than the traditional algorithm in suppressing ionospheric clutter

Inhibition of EGFR/PI3K/AKT cell survival pathway promotes TSA\u27s effect on cell death and migration in human ovarian cancer cells

Trichostatin A (TSA), a hydroxamate-type inhibitor of mammalian histone deacetylases, is emerging as one of a potentially new class of anticancer agents. TSA is known to act by promoting the acetylation of histones, leading to uncoiling of chromatin and activation of a variety of genes implicated in the regulation of cell survival, proliferation, differentiation, and apoptosis. In addition, there is an increasing appreciation of the fact that TSA may act through mechanisms other than induction of histone acetylation. Accumulated experimental data indicate that TSA activates phosphatidyl inositol-3-kinase (PI3K)/AKT signaling. Using human ovarian cancer cell line Caov3 cells, we observed that TSA induced cell death in a time- and dose-dependent manner and also inhibited cell migration. TSA transiently activated EGFR tyrosine phosphorylation and AKT activation in a time- and dose-dependent manner, which had been inhibited by EGFR inhibitor PD153035 and PI3 kinase inhibitor LY294002. We also observed that TSA transiently induced survivin expression that had been inhibited by PD153035 and LY294002, suggesting that TSA-induced survivin expression is mediated by EGFR/PI3 kinase pathway. Combination of EGFR inhibitor 153035 or PI3 kinase inhibitor LY294002 with TSA enhanced TSA-induced cell death and TSA reduction of cell migration. Collectively, our data demonstrate that TSA transiently activated EGFR/PI3K/AKT cell survival pathway, leading to expression of survivin. Inhibition of this pathway enhanced TSA-induced cell death and inhibited cell migration. Our data suggest that combination of EGFR/PI3K/AKT cell survival pathway inhibitors with TSA be a better approach to ovarian cancer treatment

preparationandopticalpropertiesofcdtecdonh2ocoreshellnanocompositesinaqueoussolution

The deposition of CdO·nH_2O on CdTe nanoparticles was studied in an aqueous phase. The CdTe nanocrystals (NCs) were prepared in aqueous solution through the reaction between Cd~(2+) and NaHTe in the presence of thioglycolic acid as a stabilizer. The molar ratio of the Cd~(2+) to Te~(2-) in the precursory solution played an important role in the photoluminescence of the ultimate CdTe NCs. The strongest photoluminescence was obtained under 4.0 of Cd~(2+)/Te~(2-) at pH～8.2. With the optimum dosage of Cd(II) hydrous oxide deposited on the CdTe NCs, the photoluminescence was enhanced greatly. The photoluminescence of these nanocomposites was kept constant in the pH range of 8.0–10.0, but dramatically decreased with an obvious blue-shifted peak while the pH was below 8.0. In addition, the photochemical oxidation of CdTe NCs with cadmium hydrous oxide deposition was markedly inhibited