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Raindrop size and flow depth interactions determine the energy available for erosion processes. A detailed laboratory study was conducted to investigate the influence of raindrop size on sediment sorting in shallow flows on steep slopes. Raindrops with sizes of 1.34, 2.45, and 4.04 mm were applied to three inflows (0.65, 1, and 2 L/min) with the same rainfall intensity (90 mm/hr). The De Brouckere mean diameter (D[4,3]) was enhanced with increases in the ratio between flow depth and raindrop size (h/d; p < 0.05), indicating that more raindrop energy dissipated in deeper flows. Moreover, a greater proportion of energy was dissipated from small raindrops than from large ones with an increasing flow depth. Particles >0.5 mm were slightly enriched by rolling under 1.34‐mm raindrop impact, whereas enrichment did not occur under 2.45‐ and 4.04‐mm raindrop impact, probably because the latter induced more severe aggregate disintegration, resulting in fewer coarse particles. The mean sediment concentrations under inflows of 0.65, 1, and 2 L/min were 101.65, 89.32, and 79.02 g/L, respectively. Shallow flows on steep slopes effectively carried detached particles; moreover, coarse particles could roll along the slopes, which was inconsistent with their behavior on gentle slopes. This study highlights the need to understand the influence of the interaction between raindrop size and flow depth on erosion processes associated with sediment size selectivity for better erosion modeling and water quality prediction. Key Points: Sediment size is significantly enhanced as the ratio between flow depth and raindrop size increases on steep slopesA greater proportion of energy is dissipated from small raindrops than from large ones with increasing flow depthCoarse particles are slightly enriched in sediment associated with bed load transport under small raindrop impact [ABSTRACT FROM AUTHOR]

Abstract: This study focuses on the investigation of the effects of computer simulation and animation (CSA) on students' cognitive processes in an undergraduate engineering course. The revised Bloom's taxonomy, which consists of six categories in the cognitive process domain, was employed in this study. Five of the six categories were investigated, including remember, understand, apply, analyze, and evaluate. Data were collected via a think‐aloud protocol involving two groups of student participants: One group learned a worked example problem with a CSA module, and the other group learned the same problem with traditional textbook‐style instruction. A new concept called frequency index was proposed for use in qualitative research that involves the quantitative comparison of the overall popularity of a particular mental activity performed by two groups of students. The results show that as compared to traditional textbook‐style instruction, CSA significantly increases students' activities in the understand category of the revised Bloom's taxonomy during learning and significantly increases students' activities in the understand, apply, analyse, and evaluate categories during subsequent problem‐solving. That learning via CSA has a profound impact on subsequent problem‐solving is attributed to intensive human–computer interactions built in the CSA learning module. [ABSTRACT FROM AUTHOR]

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Computer simulation and animation (CSA) has been receiving growing attention and wide application in engineering education in recent years. A new interactive CSA module was developed in the present study to improve student learning of particle kinetics in an undergraduate engineering dynamics course. The unique feature of this CSA module is that it integrates computer visualization with mathematical modeling, so students can directly connect engineering dynamics phenomena to underlying mathematics. A quasi-experimental pretest-post-test research design including a comparison group ( n = 65) and an intervention group ( n = 77) was implemented to assess to what extent the developed CSA module improved student learning. The results show that this new CSA module increased students' class-average conceptual and procedural learning gains by 29% and 37% respectively. The difference in learning gains between the two groups is statistically significant ( Z = −4.526, p = 0.000) based on a nonparametric statistical Mann-Whitney U test. It is found that the improvement of students' conceptual understanding and the improvement of their procedural skills are asymmetrical in this CSA learning environment. The CSA module can serve as an excellent tool to supplement traditional lectures, but cannot fully replace human teachers or tutors in teaching. [ABSTRACT FROM AUTHOR]

The biological effects on cardiovascular development of chicken embryos were examined after radiation exposure using mobile phone (900 MHz; specific absorption rate˜1.07 W/kg) intermittently 3 h per day during incubation. Samples were selected by morphological and histological methods. The results showed the rate of embryonic mortality and cardiac deformity increased significantly in exposed group ( P < 0.05). No any histological pathological changes were observed on Day 5-7 (D5-D7) of incubation. A higher distribution of lipid droplets was unexpectedly present in myocardial tissue from the exposure groups on D10-D13. Soon afterwards, myofilament disruption, atrioventricular valve focal necrosis, mitochondria vacuolization and atrial natriuretic peptide ( ANP) decrease appeared on D15-D21 of incubation. Comet assay data showed the haemocyte mean tail in the exposed group was significantly larger than that of the control ( P < 0.01). The arterial vascular wall of exposed group was thicker ( P < 0.05) than that of the control on D13, which was reversed to normal in later stages. Our findings suggest that long-term exposure of MPR may induce myocardium pathological changes, DNA damage and increased mortality; however, there was little effect on vascular development. [ABSTRACT FROM AUTHOR]

Background Sevoflurane post-conditioning ( Spost C) protects young hearts against ischemia-reperfusion injury. It is unknown whether the infarct-limiting effect is also maintained in aged cohorts and whether there are age-associated differences in the underlying mechanisms. Methods Young or old rats were randomly subjected to 30-min myocardial ischemia, followed by 120-min reperfusion in vivo, with or without SpostC in the presence or absence of phosphatidylinositol 3-kinase ( PI3K) or mitogen-activated protein kinase kinase 1/2 ( MEK1/2) inhibitor. Western blotting was used to determine the phosphorylation of protein kinase B ( Akt) and extracellular signal-regulated kinase 1/2 ( ERK1/2). Myocardial nicotinamide adenine dinucleotide ( NAD+) level was measured to indicate mitochondrial permeability transition pore ( mPTP) opening. Results SpostC significantly decreased infarct size in young (35 ± 4% vs. 56 ± 3%, P < 0.05) but not old rats (45 ± 3% vs. 47 ± 4%, P > 0.05) compared with each control group. SpostC substantially augmented phosphorylation of Akt (0.74 ± 0.03 arbitrary units vs. 0.27 ± 0.03 arbitrary units, P < 0.05) or ERK1/2 (0.85 ± 0.04 arbitrary units vs. 0.29 ± 0.04 arbitrary units, P < 0.05) compared with control group, which was abolished by PI3K or MEK1/2 inhibitor in young rats, respectively, but failed to activate Akt and ERK1/2 in old rats. NAD+ level (nmol/g tissue) was higher in SpostC group in young (118.57 ± 9.27 vs. 46.78 ± 4.54, P < 0.05) but not old rats (58.50 ± 7.16 vs. 61.15 ± 5.50, P > 0.05) compared with each control group. PI3K or MEK1/2 inhibitor abrogated the infarct-sparing effect and inhibition of loss of NAD+ induced by SpostC in young rats, respectively. Conclusion SpostC-mediated cardioprotection in young rats is not effective in senescent rats, which may at least be the consequence of failure to activate Akt and ERK1/2, and resultant failure to inhibit mPTP opening. [ABSTRACT FROM AUTHOR]

SIRT2 is a NAD + -dependent deacetylase that deacetylates a diverse array of protein substrates and is involved in many cellular processes, including regulation of inflammation. However, its precise role in the inflammatory process has not completely been elucidated. Here, we identify heat-shock protein 90α (Hsp90α) as novel substrate of SIRT2. Functional investigation suggests that Hsp90 is deacetylated by SIRT2, such that overexpression and knock-down of SIRT2 altered the acetylation level of Hsp90. This subsequently resulted in disassociation of Hsp90 with glucocorticoid receptor (GR), and translocation of GR to the nucleus. This observation was further confirmed by glucocorticoid response element (GRE)-driven reporter assay. Nuclear translocation of GR induced by SIRT2 overexpression repressed the expression of inflammatory cytokines, which were even more prominent under lipopolysaccharide (LPS) stimulation. Conversely, SIRT2 knock-down resulted in the up-regulation of cytokine expression. Mutation analysis indicated that deacetylation of Hsp90 at K294 is critical for SIRT2-mediated regulation of cytokine expression. These data suggest that SIRT2 reduces the extent of LPS-induced inflammation by suppressing the expression of inflammatory factors via SIRT2-Hsp90-GR axis., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

PTEN is a tumour suppressor that is frequently mutated in a variety of cancers. Hence, PTEN has significant potential as a therapeutic molecule. PTEN-long is an alternative translation variant, with an additional 173 amino acids added to the N-terminal of the canonical PTEN when CUG of the mRNA is utilized as the start codon. PTEN-long is secreted into serum and can re-enter cells throughout the body. One of the major barriers for gene therapy is to efficiently and specifically deliver DNA or RNA material to target cells. As an alternative approach, if a therapeutic protein can be directly delivered to target cell of interest, it should theoretically function well within the cells, particularly for genes that are deficiently expressed in vivo. Most therapeutic proteins are incapable of efficiently permeating the cell membrane. In this study, we have employed CRISPR/Cas9 gene editing tool combined with single-stranded template to edit CTG of PTEN-long to ATG in the genome. Two guide RNAs close to CTG site were found to have similar efficiency in driving PTEN-long expression. Furthermore, we detected PTEN-long expression in transfected whole-cell lysate and in concentrated culture media in Western blot. Interestingly, the culture media of PTEN-long expression can reduce Akt phosphorylation level and repress U87 cell proliferation compared to wild-type U87 or control media. Taken together, PTEN-long driven by CRISPR/Cas9 imports and exports cells and represses nearby cell proliferation, indicating the PTEN-long generated by CRISPR/Cas9 has potential to be an alternative strategy for PTEN gene therapy., (© 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Virus-like particles (VLPs) are being currently investigated in vaccines against viral infections in humans. There are different recombinant-protein-expression systems available for obtaining the necessary VLP preparation for vaccination. However, the differences in post-translational modifications of the recombinant proteins obtained and their differences in efficacy in eliciting an anti-viral response in vaccines are not well established. In this study we have compared the post-translational modifications of human papillomavirus type-6b major capsid protein L1 (HPV 6bL1) expressed using recombinant baculovirus (rBV) in Sf9 (Spodoptera frugiperda) insect cells, with the protein expressed using recombinant vaccinia virus (rVV) in CV-1 kidney epithelial cells. Two-dimensional gel electrophoresis of biosynthetically labelled rBV-expressed HPV 6bL1 showed several post-translationally modified variants of the protein, whereas rVV-expressed HPV 6bL1 showed only a few variants. Phosphorylations were detected at threonine and serine residues for the L1 expressed from rBV compared with phosphorylation at serine residues only for the L1 expressed from rVV. HPV 6bL1 expressed using rBV incorporated [(3)H]mannose and [(3)H]galactose, whereas HPV 6bL1 expressed using rVV incorporated only [(3)H]galactose. We conclude that post-translational modification of recombinant HPV 6bL1 can differ according to the system used for its expression. Since recombinant L1 protein is a potential human-vaccine candidate, the implication of the observed differences in post-translational modifications on immunogenicity of L1 VLPs warrants investigation.