Multiscale Entropy Analysis of Page Views: A Case Study of Wikipedia

In this study, the Wikipedia page views for four selected topics, namely, education, the economy/finance, medicine, and nature/environment from 2016⁻2018 are collected and the sample entropies of the three years’ page views are estimated and investigated using a short-time series multiscale entropy (sMSE) algorithm for a comprehensible understanding of the complexity of human website searching activities. The sample entropies of the selected topics are found to exhibit different temporal variations. In the past three years, the temporal characteristics of the sample entropies are vividly revealed, and the sample entropies of the selected topics follow the same tendencies and can be quantitatively ranked. By taking the 95% confidence interval into account, the temporal variations of sample entropies are further validated by statistical analysis (non-parametric), including the Wilcoxon signed-rank test and the Mann-Whitney U-test. The results suggest that the sample entropies estimated by the sMSE algorithm are feasible for analyzing the temporal variations of complexity for certain topics, whereas the regular variations of estimated sample entropies of different selected topics can’t simply be accepted as is. Potential explanations and paths in forthcoming studies are also described and discussed

Insight into the Mechanism of Glycerol Dehydration and Subsequent Pyridine Synthesis

In the present study, glycerol was exploited as the feedstock to synthesize pyridine with ammonia gas as a carrier and reactant through thermal conversion. A density functional theory (DFT) at the M06-2X method was applied to understand the mechanism of glycerol dehydration, the ammonization of oxygenated compounds, and the condensation of imines. The results confirmed that glycerol could be directly converted into pyridine in ammonia atmosphere at 550 degrees C. The overall view of the thermal conversion mechanism of glycerol was compared with the previous experimental data and the proposed mechanisms, which indicated that the neutral glycerol dehydration process should mainly produce acrolein, acetaldehyde, formaldehyde, and acetol. The produced oxygenated compounds (acrolein and acetaldehyde) can react with ammonia to form imine, which would further undergo Michael addition, a Diels-Alder reaction, deammonization, and dehydrogenation to form pyridine. In a catalytic condition, ZSM-5 not only plays a shape-selective effect on the conversion of glycerol to pyridine but also changes the path of the reaction. The structure of ZSM-5 limits the formation of multisubstituted pyridine products, which is beneficial to the formation of pyridine and monosubstituted pyridine. Protonated vinylamine intermediates may be a critical step limiting pyridine yield and selectivity. The kinetic analysis that is based on transition state theory was consistent with product contribution in experiments. The present study confirmed the selectivity and the conversion route of glycerol to pyridine

Evaluation of TG202 inhibitor for tubing steels in 15% hydrochloric acid by electrochemical noise technology

Acid fracturing is an effective technology for increasing oil and gas production. However, the acid will cause serious corrosion to the tubing. In this paper, the inhibition performance of the TG202 inhibitor for acidizing of high temperature and high-pressure gas wells on N80 carbon steel and 13Cr martensitic stainless-steel tubing in 15% hydrochloric acid was studied by electrochemical noise technology. The results showed that with the increase of TG202 inhibitor content, the noise resistance increased and the corrosion rate of tubing steel decreased. Under the same condition, the order of corrosion rate of tubing steels: 13Cr > HP-13Cr > N80 > P110. The pitting corrosion of HP-13Cr and 13Cr is significant. The research showed that the TG202 inhibitor had a protective effect on tubing during acidizing. The inhibition mechanism of the TG202 inhibitor was discussed

Significant reduction in creep life of P91 steam pipe elbow caused by an aberrant microstructure after short-term service

Abstract P91 steel is an important steam pipe for ultra-supercritical power plants due to its excellent creep strength, which generally has a design life of 100,000 h. Here, we found a significant aberrant decrease in the creep rupture life of a main steam pipe elbow after only 20,000 h of service. The microstructure in the aberrant piece exhibited a decomposition of martensitic lath into blocky ferrite due to recrystallization and accumulation of M23C6 as well as formation of the Laves phase along the prior austenitic grain boundaries, resulting in the decrease of hardness that no long meet ASME standard requirement. The creep testing of the P91 piece at 550–600 °C and 85–140 MPa shows that the influence of temperature on the cavity formation and cracking is greater than that of the applied stress. The rupture life is nearly two orders of magnitude shorter than the normal P91, attributing to the creep damage of the subgrain growth, M23C6 and Laves phase coarsening (aggregation approaching 3.4 μm). The residual life of the aberrant piece was evaluated to be 53,353 h based on the Larson–Miller parameter, which is much shorter than the design life, suggesting the safety operation of the elbow area should be paid more attention during the afterward service periods. P91 steel, main steam pipe elbow, aberrant microstructure, service degradation, creep life predictio

Gut-on-a-chip for exploring the transport mechanism of Hg(II)

Abstract Animal models and static cultures of intestinal epithelial cells are commonly used platforms for exploring mercury ion (Hg(II)) transport. However, they cannot reliably simulate the human intestinal microenvironment and monitor cellular physiology in situ; thus, the mechanism of Hg(II) transport in the human intestine is still unclear. Here, a gut-on-a-chip integrated with transepithelial electrical resistance (TEER) sensors and electrochemical sensors is proposed for dynamically simulating the formation of the physical intestinal barrier and monitoring the transport and absorption of Hg(II) in situ. The cellular microenvironment was recreated by applying fluid shear stress (0.02 dyne/cm2) and cyclic mechanical strain (1%, 0.15 Hz). Hg(II) absorption and physical damage to cells were simultaneously monitored by electrochemical and TEER sensors when intestinal epithelial cells were exposed to different concentrations of Hg(II) mixed in culture medium. Hg(II) absorption increased by 23.59% when tensile strain increased from 1% to 5%, and the corresponding expression of Piezo1 and DMT1 on the cell surface was upregulated

Differences in responses to X-ray exposure between osteoclast and osteoblast cells

Radiation-induced bone loss is a potential health concern for cancer patients undergoing radiotherapy. Enhanced bone resorption by osteoclasts and decreased bone formation by osteoblasts were thought to be the main reasons.In this study, we showed that both pre-differentiating and differentiating osteoclasts were relatively sensitive to X-rays compared with osteoblasts. X-rays decreased cell viability to a greater degree in RAW264.7 cells and in differentiating cells than than in osteoblastic MC3T3-E1 cells. X-rays at up to 8 Gy had little effects on osteoblast mineralization. In contrast, X-rays at 1 Gy induced enhanced osteoclastogenesis by enhanced cell fusion, but had no effects on bone resorption. A higher dose of X-rays at 8 Gy, however, had an inhibitory effect on bone resorption. In addition, actin ring formation was disrupted by 8 Gy of X-rays and reorganized into clusters. An increased activity of Caspase 3 was found after X-ray exposure. Actin disorganization and increased apoptosis may be the potential effects of X-rays at high doses, by inhibiting osteoclast differentiation. Taken together, our data indicate high radiosensitivity of osteoclasts. X-ray irradiation at relatively low doses can activate osteoclastogenesis, but not osteogenic differentiation. The radiosensitive osteoclasts are the potentially responsive cells for X-ray-induced bone loss.KEYWORDS: ionizing radiation, osteoblasts, osteoclasts, differentiatio

Mouse intestinal Lgr5+ stem cells are more sensitive to heavy ion irradiation than Bmi1+ stem cells

Before the human exploration of the Mars or other long-duration missions in outer space, the risks of cancer and other radiation injury induced by space radiations, containing high linear energy transfer (LET) particles such as heavy ions, must be accurately estimated and mitigated. On the other hand, accelerated carbon ions have been successfully used for clinical tumor treatment, and their damages to normal tissues are also of concern. Therefore, heavy ion particles are severely risky not only to manned space exploration but also to the patients experiencing particle radiotherapy [1,2].Earlier studies suggested that intestine was a radio-sensitive tissue which was seriously injured, and then lost main digestion absorption function for individual survival after low LET radiation such as γ-rays and X-rays. But there is much uncertainty in understanding heavy-ion-induced intestinal injury because sufficient in vivo mechanistic data are not available. Here, we demonstrate for the first time that the Bmi1-expressing cells are more resistant to carbon ions than Lgr5+ cells in mouse intestine and may be the major stem cells for the self-renewal of intestinal cells after intestinal injury induced by carbon ion irradiation