Underground transportation system risk assessment to mitigate vulnerability against natural disasters through intelligent urban management

Quantitative and qualitative monitoring and evaluation of risk management programs will play an important role in the development of Tehran metropolitan railway transport. Considering the tectonic studies, seismic zones, land degradation and faults in north and south of Tehran, the development of underground railway lines, the assessment of the vulnerability of subway stations and the escalation of the crisis with the destruction of urban exhausted earthquakes is very important with the occurrence of earthquake and flood. This study, focusing on the issue of risk assessment and vulnerability of the development of the rail transport network and the approach to physical and aerospace hazard monitoring of metro stations. For this purpose, three selected metro stations in Tehran were studied. In the research, a combined method based on library studies, review of records and records, Delphi technique, AHP method, and overlaying of layers have been used. The results of the vulnerability assessment indicate that each of Tajirish, Nawab and Darvazeh Shemiran, with a risk number of 5.10, 5.76, and 5.79, are in the risk limit range, respectively. In fact, all stations need to adopt smart measures and management and executive solutions to reduce potential damage

Interatomic coulombic decay rate in endohedral complexes

Interatomic coulombic decay (ICD) in van der Waals endohedral complexes was predicted to be anomalously fast. However, the available theoretical calculations of the ICD rates in endohedral complexes only consider the equilibrium geometry, in which the encapsulated atom is located at the centre of the fullerene cage. Here we show analytically that the dominant contribution of the dipole plasmon resonance to ICD does not deviate from its equilibrium geometry value, while contributions of higher multipole plasmons to the ICD can be neglected for most atomic displacements possible for an endohedral complex at room temperature. This is in contrast to the behaviour predicted for ionic endohedral compounds. Our results show that the conclusion of the earlier works on the ultrafast character of the ICD in endohedral complexes holds generally for a wide range of geometries possible under a thermal distribution, rather than only for the equilibrium geometry

Improved Differentiation of Mesenchymal Stem Cells into Hepatocyte-like Cells using FGF4 and IGF-1 in 3D Culture

Human Umbilical Cord Mesenchymal Stem Cells (UCMSCs) are considered as an excellent candidate for cell therapy to treat end-stage liver disease. Fibroblast Growth Factor-4 (FGF4), Hepatocyte Growth Factor, and Insulin-like Growth Factor-1 are some of the critical cytokines involved in liver development and regeneration. To evaluate the differentiation potency of cells into hepatocyte-like cells we used these cytokines. UCMSCs were isolated from Wharton's jelly of fullterm infants. The cells were characterized as MSCs by flow-cytometry and their multilineage differentiation capacity. Then, UCMSCs were cultured in 3D collagen scaffold and hepatogenic media with or without FGF4 for 21 days and the data were compared to control. The expression of liver specific genes was evaluated by real-time quantitative RT-PCR and immunocytochemistry. These cells expressed MSC markers and could differentiate into adipocytes and osteocytes. A non–significant higher level of liver specific genes, such as cytokeratin-18 and 19, alpha-fetoprotein and albumin, and also a significant higher level of CYP2B6 expressed by UCMSCs in hepatogenic medium containing FGF4 compared with control. In some specimens, cytokeratin-19-positive cells surrounded a luminal space within collagen scaffolds. Liver-specific marker expression was increased by pre-exposing the cells to FGF4 before treating with IGF-1 and HGF in 3D collagen scaffold. Abbreviations: UCMSCs: Human Umbilical Cord Mesenchymal Stem Cells; FGF4: Fibroblast Growth Factor 4; HGF: Hepatocyte Growth Factor; IGF-1: Insulin-like Growth Factor-1; MSCs: Mesenchymal Stem Cells; ICG: Indocyanine green; PAS: periodic acid Schiff; CK-18: cytokeratin-18; CK-19: Cytokeratin-19; AFP: alpha-fetoprotein; G6P: glucose 6 phosphatase; PEPCK: phosphoenolpyruvate carboxykinase; TAT: tyrosine amino transferase; FBS: Fetal Bovine Serum; OSM: oncostatin M; RT-PCR: Reverse Transcription Polymerase Chain Reaction; PBS: Phosphate-Buffered Saline; Hep- Par1: Hepatocyte paraffin 1; DAB: Diaminobenzidine; CYP2B6: Cytochrome P450 2B6

Selective synthesis of dimethyl ether on eco-friendly K10 montmorillonite clay

The methanol dehydration reaction was studied over environmentally benign, easily accessible and inexpensive K10 montmorillonite clay used as the catalyst at a temperature range between 200–700 °C. Nearly 100% selectivity towards dimethyl ether (DME) at 80% methanol conversion was observed at 300 °C. However, upon heating, the selectivity shifted and the catalyst produced formaldehyde as well as an almost 1:1 M ratio of methane and carbon monoxide at 700 °C. Calcination at 300 °C increased the catalyst acidity due to desorption of chemisorbed water, thereby enhancing the methanol conversion to form DME. Higher calcination temperatures negatively affected the catalyst structure and, therefore, its activity. Catalyst characterization by means of X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), and solid-state Nuclear Magnetic Resonance (MAS NMR) spectroscopy, revealed that the calcination temperature affected the near surface Si/Al ratio as well as the surface hydroxyl groups. It was concluded that the density of the surface Brønsted acid sites is directly proportional to methanol conversion to DME

Prominent role of mesopore surface area and external acid sites for the synthesis of polyoxymethylene dimethyl ethers (OME) on a hierarchical H-ZSM-5 zeolite

H-ZSM-5 zeolite has been shown to be an active catalyst for the synthesis of polyoxymethylene dimethyl ethers (OME). However, we demonstrated – by passivation of the zeolite's external surface – that the reaction rate is limited due to severe internal diffusion limitations of the reactants and products. External acid sites thus played a more prominent role in the observed overall reaction rate compared to the acid sites in the zeolite's micropores. Through controlled introduction of an intercrystalline network of mesopores the zeolite's activity was significantly enhanced by allowing a more significant part of the reaction to take place within the zeolite's micropores. By optimising alkaline treatment and consequent acid wash of H-ZSM-5, we achieved a two-fold increase in the initial reaction rate and a 10% increase in selectivity towards OME with 3 to 5 oxymethylene units (OME3–5), which are the more desirable products

The Effect of Sand and Dust Storms (SDSs) and Rain on the Performance of Cellular Networks in the Millimeter Wave Band

Future cellular systems are expected to use millimeter-wave (mm-Wave) frequency bands in addition to the existing microwave bands under 6 GHz. Severe weather conditions, including sand and dust storms (SDSs) and heavy rainfalls, challenge reliable communications over wireless links at those higher frequencies. In such conditions, besides frequency-dependent path-loss, radio signals experience additional attenuation. The SDS attenuation is related to visibility, receiver distance to the storm origin point, soil type, frequency, temperature and humidity. On the other hand, the rainfall attenuation is affected by rainfall rate, polarization, carrier frequency, temperature and raindrop size distribution. Leveraging on experimental measurements carried out in previous works, a novel unified mathematical framework is introduced in this paper to include SDS/rainfall-dependent attenuation in the performance evaluation of terrestrial wireless cellular networks in terms of coverage probability, bit error rate (BER) and achievable rate in the mm-Wave band. Extensive numerical results are presented to show the effects of the different SDS/rainfall parameters on performance, showing that the degradation due to SDS is generally higher than that due to rain and may cause a reduction of even six orders of magnitude in the average achievable bit rate when the frequency increases from 28 to 38 GHz

Apigenin as Tumor Suppressor in Cancers: Biotherapeutic Activity, Nanodelivery, and Mechanisms With Emphasis on Pancreatic Cancer

Pancreatic cancer is the most lethal malignancy of the gastrointestinal tract. Due to its propensity for early local and distant spread, affected patients possess extremely poor prognosis. Currently applied treatments are not effective enough to eradicate all cancer cells, and minimize their migration. Besides, these treatments are associated with adverse effects on normal cells and organs. These therapies are not able to increase the overall survival rate of patients; hence, finding novel adjuvants or alternatives is so essential. Up to now, medicinal herbs were utilized for therapeutic goals. Herbal-based medicine, as traditional biotherapeutics, were employed for cancer treatment. Of them, apigenin, as a bioactive flavonoid that possesses numerous biological properties (e.g., anti-inflammatory and anti-oxidant effects), has shown substantial anticancer activity. It seems that apigenin is capable of suppressing the proliferation of cancer cells via the induction of cell cycle arrest and apoptosis. Besides, apigenin inhibits metastasis via down-regulation of matrix metalloproteinases and the Akt signaling pathway. In pancreatic cancer cells, apigenin sensitizes cells in chemotherapy, and affects molecular pathways such as the hypoxia inducible factor (HIF), vascular endothelial growth factor (VEGF), and glucose transporter-1 (GLUT-1). Herein, the biotherapeutic activity of apigenin and its mechanisms toward cancer cells are presented in the current review to shed some light on anti-tumor activity of apigenin in different cancers, with an emphasis on pancreatic cancer. © Copyright © 2020 Ashrafizadeh, Bakhoda, Bahmanpour, Ilkhani, Zarrabi, Makvandi, Khan, Mazaheri, Darvish and Mirzaei

Determination of maternal risk factors of preterm delivery: Adjusted for sparse data bias; results from a population-based case-control study in Iran

Objective To determine the maternal risk factors associated with preterm delivery in Iran. Methods A population-based case-control study was conducted including 48 women having preterm delivery (case group) and 100 women having term delivery (control group) between March 2007 and March 2012 in the maternity hospitals of the Selseleh County, Lorestan province, Iran. Information regarding maternal risk factors was collected by structured interview and reviewing the medical records. The maternal risk factors associated with preterm delivery were identified using univariate and multivariable logistic regression analysis after adjusting the sparse data bias. The area under the receiver operating characteristic (ROC) curves was estimated to evaluate the discrimination power of the statistical models. Results Multivariable analysis demonstrated that multiparty (odds ratio OR, 14.23; 95% confidence interval CI, 1.60-127.05), history of gestational diabetes (OR, 0.10; 95% CI, 0.01-0.99), thyroid dysfunction (OR, 97.32; 95% CI, 5.78-1,637.80), urinary tract infection (OR, 16.60; 95% CI, 3.20-85.92), and taking care during pregnancy (OR, 0.12; 95% CI, 0.03-0.50) had significant impact on preterm delivery after adjusting the potential confounders. The area under the ROC curve for the aforementioned maternal risk factors was 0.86 (95% CI, 0.80-0.92). Conclusion Our study provides evidence for the associations between multiparty, history of gestational diabetes, thyroid dysfunction, urinary tract infection, as well as taking care during pregnancy, and preterm delivery. © 2020 Korean Society of Obstetrics and Gynecology