Analysis of the mechanism of enhanced heat transfer by nanofluids.

CONTEXT: Industrial production and humans cannot exist without energy, but the low efficiency of the heat transfer in the excessive use of energy is the most significant aspect of energy saving and emission reduction. Molecular dynamics simulation methods are devoted to simulate the heat transfer efficiency of a nanofluid system with different particle sizes, and the heat transfer enhancement mechanism of the nanofluid is simulated and studied from a microscopic perspective. The analysis showed that as nanoparticle size increases, the thermal conductivity of the Al-Ar nanofluid tends to decrease, but all of them are still higher than the thermal conductivity of the liquid argon system. According to the findings of the density and radial distribution function analyses, it can be seen that the microstructure of the system changes after putting solid nanoparticles to the original fluid. This alteration in the system's microstructure is the primary component responsible for the increased heat transfer efficiency of nanofluids. METHODS: In this paper, based on the theory of molecular dynamics, the simulation calculations were mainly performed using LAMMPS software, which is a commonly used open source computational program in the field of MD simulation research. VMD is used for visualization and analysis. The Lennard-Jones potential function was used in the simulation to accurately describe the forces acting between the atoms.

CircHECTD1 up-regulates mucin 1 expression to accelerate hepatocellular carcinoma development by targeting microRNA-485-5p via a competing endogenous RNA mechanism.

BACKGROUND: Non-coding RNAs have attracted considerable attention for their vital role in cancer. The purpose of this study was to determine the effects of non-coding RNAs on hepatocellular carcinoma (HCC) and reveal their regulatory mechanism in the pathophysiological process. METHODS: We measured the expression of mucin 1 (MUC1) and miR-485-5p in tissues from 15 HCC patients and in liver cancer cell lines by quantitative real-time polymerase chain reaction and Western blot, screened for aberrantly expressed microRNAs (miRNAs) by miRNA microarrays. Bioinformatics tools were used to find the miRNA and circular RNA that regulated MUC1, which were validated by RNA immunoprecipitation assay and luciferase reporter assay. Cell counting kit-8, Transwell assays, and flow cytometry were used to conduct functional experiments. Proteins were examined by western blot and immunohistochemical staining assays. Significant differences between groups were estimated using the one-way analysis of variance. A P < 0.05 was considered statistically significant. RESULTS: MUC1 was overexpressed in HCC tissues compared with that in paratumor tissues (normal vs. tumor, 1.007 ±â€Š0.215 vs. 75.213 ±â€Š18.403, t = 18.401, P < 0.001) while miR-485-5p was down-regulated (normal vs. tumor, 4.894 ±â€Š0.684 vs. 1.586 ±â€Š0.398, t = 16.191, P < 0.001). Inhibition of miR-485-5p promoted cell proliferation (73.33% ±â€Š5.13% vs. 41.33% ±â€Š3.51%, t = 8.913, P < 0.001), migration (102 ±â€Š8 cells vs. 46 ±â€Š8 cells, t = 8.681, P < 0.001), invasion (59 ±â€Š7 cells vs. 28 ±â€Š2 cells, t = 8.034, P < 0.01), and suppressed apoptosis (22.64% ±â€Š6.97% vs. 36.33% ±â€Š3.96%, t = 2.958, P < 0.05) of HepG2 cells with which MUC1 is knocked down. Mechanically, miR-485-5p binds to MUC1, while circHECTD1 binds to miR-485-5p, resulting in the indirect up-regulation of the MUC1 level. CONCLUSIONS: Our findings reveal that circHECTD1 facilitates HCC progression by sponging miR-485-5p to up-regulate MUC1.

The molecular structure of novel pyriform spidroin (PySp2) reveals extremely complex central repetitive region.

Orb-weaving spiders produce a diversity of silk fibers throughout their entire lifecycle, and each silk type is given a specific purpose. As a dry fiber material with wet glue, pyriform silks are different from other silk fibers and make the attachment discs which are used for bonding fibers together and attaching dragline silk to other substrates. To date, only two full-length pyriform spidroin 1 (PySp1) gene sequences were identified. Here we present a novel full-length pyriform spidroin 2 (PySp2) from orb-weaving spider, Araneus ventricosus. Although the A. ventricosus PySp2 lack the long linker regions, the central repetitive region of PySp2 is more complex than PySp1 and can be classified into four types of repetitive regions including three novel repetitive sequences and one type of repetitive region that is similar to PySp1 repeats. Prediction of hydrophobicity of A. ventricosus PySp2 reveals the two new repetitive regions display strong hydrophilicity. Analysis of CD spectrum and secondary structure prediction for A. ventricosus PySp2 repeat unit reveal α-helix conformation dominates the repetitive region. Furthermore, recombinant protein-based artificial fibers show the single repeat unit is sufficient for self-assembling into silk fiber.

Sarcomatoid thymic carcinoma arising in metaplastic thymoma: a case report.

Metaplastic thymoma is an extremely rare tumor. To date, only 17 cases of metaplastic thymoma have been reported. To the best of the authors' knowledge, this is the second reported case of a sarcomatoid carcinoma arising in metaplastic thymoma; the carcinoma in this case is larger than that in the previous case. A 63-year-old woman with cough and asthenia for 2 weeks was admitted to the hospital. Computed tomography (CT) revealed a giant mass on the right side of the front mediastinum medium. The mediastinal tumor was excised, and additional pathological examinations, immunohistochemical tests, and electron-microscopic tests were performed. The tumor was diagnosed as a sarcomatoid carcinoma arising in metaplastic thymoma. Here, the authors discuss the clinical pathology of the sarcomatoid carcinoma arising in metaplastic thymoma and describe the biological behaviors with respect to the pathological features.