56 research outputs found
Nonlinear actuation of micromechanical Casimir oscillators with topological insulator materials toward chaotic motion:Sensitivity on magnetization and dielectric properties
We have investigated the dynamical actuation of micro-electromechanical systems under the influence of attractive and repulsive Casimir forces between topological insulator plates as a function of their dielectric function and coating magnetization. The analysis of the Casimir force in the limit of strong and weak magnetization shows that the attractive force, which is produced for plate magnetizations in the same direction, is greater than the repulsive force that is produced for opposite magnetizations. However, both forces remain comparable for intermediate magnetizations. Moreover, for weak magnetization, the attractive force becomes stronger for an increasing dielectric function, while the opposite occurs for the repulsive force. On the other hand, increasing magnetization decreases the influence of the dielectric function on both the repulsive and attractive forces. Furthermore, for conservative systems, bifurcation and phase portrait analysis revealed that increasing magnetization decreases the regime of stable operation for devices with attractive forces, while their operation remains always stable under the presence of repulsive forces. Finally, for non-conservative periodically driven systems, the Melnikov function and Poincaré portrait analysis show that for magnetizations in the same direction leading to strong attractive Casimir forces, chaotic motion toward stiction is highly likely to occur preventing the long-term prediction of actuating dynamics. A remedy for this situation is obtained by the application of any magnetization in opposite directions between the interacting surfaces since the repulsive force makes it possible to prevent stiction
Squamous cell carcinoma (SCC) arising in esophageal colon interposition
The idea of using the colon to replace a resected esophagus has a long history. The colon has become a favored organ for esophageal reconstruction in adults with esophageal cancer when the stomach is not suitable or is unavailable. In this article, we introduce an 84-year-old woman that she had surgery 40 years ago and presented with an invasive well differentiated squamous cell carcinoma of colonic origin in reconstructed esophagus. © 2017 The Author
Psychometric Properties of the Inventory of Statements about Self-Injury (ISAS) in Iranian Opioid and Alcohol Abusers
Background: Non-suicidal self-injury (NSSI) is one of the most dangerous behaviors linked to substance abuse. The Inventory of Statements About Self-Injury (ISAS) has been developed to better understanding the factors associated with the onset and maintenance of NSSI behaviors. Objective: The ISAS was translated into the Persian language to study its psychometric properties in Iranian population of opioid and alcohol abusers. Methods: This is a psychometric study investigating opioid and alcohol abusers in Iran, including those residing in addiction rehabilitation camps, prisons, hospitals, and addiction treatment clinics dispensing methadone in 2017. The sample size of this study was 470. The subjects completed the Inventory of Statements About Self-Injury, Barrat Impulsiveness Scale (BIS), and the Distress Tolerance Scale (DTS). Results: The test-retest results were estimated for two weeks using the Intra-class Correlation Coefficient (ICC). The absolute reliability was determined to be 2.62. There was a significant correlation between convergent and divergent instruments. The results of the exploratory factor analysis on 235 individuals in the sample showed all subscales of the inventory measure a single factor in the Iranian population. The total Cronbach�s alpha coefficient for this subscale was 0.93. Also, the results of confirmatory factor analyses on the rest of the sample (235), after applying the AMOS software suggestions to improve the model, showed this inventory was a good indicator for this population (�2 = 131.69; P < 0.001; df = 56; �2/df = 2.35; CFI = 0.97; RMSEA = 0.76; GFI = 0.92). Conclusions: The Persian version of the Inventory of Statements About Self-Injury has high validity and reliability among the opioid and alcohol-abusing population in Iran. Copyright © 2020, Author(s)
Effects of Aflatoxin B1 and Fumonisin B1 on Blood Biochemical Parameters in Broilers
The individual and combined effects of dietary aflatoxin B1 (AFB1) and fumonisin B1 (FB1) on liver pathology, serum levels of aspartate amino-transferase (AST) and plasma total protein (TP) of broilers were evaluated from 8 to 41 days of age. Dietary treatments included a 3 × 3 factorial arrangement with three levels of AFB1 (0, 50 and 200 μg AFB1/kg), and three levels of FB1 (0, 50 and 200 mg FB1/kg). At 33 days post feeding, with the exception of birds fed 50 mg FB1 only, concentrations of AST were higher (p < 0.05) in all other treatment groups when compared with controls. Plasma TP was lower (p < 0.05) at six days post feeding in groups fed 200 μg AFB1/kg alone or in combination with FB1. At day 33 days post feeding, with the exception of birds fed the highest combination of AFB1 and FB1 which had higher plasma TP than control birds, plasma TP of birds fed other dietary treatments were similar to controls. Broilers receiving the highest levels of AFB1 and FB1 had bile duct proliferation and trabecular disorder in liver samples. AFB1 singly or in combination with FB at the levels studied, caused liver damage and an increase in serum levels of AST
The risk factors of prostate cancer: A multicentric case-control study in Iran
Prostate cancer (PC), in Iran, is the third most frequently diagnosed visceral cancer among men and the seventh most common underlying cause of cancer mortality. We evaluated the relation between speculated factors and PC risk using data from a multicentric case-control study conducted in Iran from 2005 to 2007 on 130 cases of incident, clinicopathologically confirmed PC, and 75 controls admitted to the same network of hospitals without any malignant disease. Odds ratios(OR) and corresponding 95 confidence intervals (CIs) were estimated using conditional logistic regression models. The risk of PC was increased with aging (OR: 5.35, 95 CI: 2.17-13.19; P<0.0001), and with the number of sexual intercourse �2 times/week (OR: 3.14, 95 CI: 1.2-8.2; P=0.02). One unit elevation in serum estradiol and testosterone concentration was related to increase (OR: 1.04, 95 CI: 1.01-1.06; P=0.006) and decrease (OR: 0.79; 95 CI: 0.64-0.96; P=0.02) of PC risk, respectively. Cases were less likely to have a history of diabetes (OR: 0.34, 95 CI: 0.12-0.98; P=0.04). Increasing in dietary consumption of lycopene and fat was associated with declined (OR: 0.45, 95 CI: 0.09-2.12) and increased (OR: 2.38, 95 CI: 0.29-19.4) PC development, respectively. Other factors including educational level, marriage status, dietary meat consumption, vasectomy and smoking have not been shown to affect PC risk in the Iranian population. Ourstudy adds further information on the potential risk factors of PC and is the first epidemiologic report from Iran. However, justification of these results requires more well-designed studies with a larger number of participants
Knowledge Management and Organisational Culture
This international Handbook provides a comprehensive overview of key topics, debates and issues within the now well-established field of Knowledge Management (KM)
Liver cell therapy: is this the end of the beginning?
The prevalence of liver diseases is increasing globally. Orthotopic liver transplantation is widely used to treat liver disease upon organ failure. The complexity of this procedure and finite numbers of healthy organ donors have prompted research into alternative therapeutic options to treat liver disease. This includes the transplantation of liver cells to promote regeneration. While successful, the routine supply of good quality human liver cells is limited. Therefore, renewable and scalable sources of these cells are sought. Liver progenitor and pluripotent stem cells offer potential cell sources that could be used clinically. This review discusses recent approaches in liver cell transplantation and requirements to improve the process, with the ultimate goal being efficient organ regeneration. We also discuss the potential off-target effects of cell-based therapies, and the advantages and drawbacks of current pre-clinical animal models used to study organ senescence, repopulation and regeneration
Cancer stem cells as a therapeutic target in bladder cancer
Bladder cancer is one of the most prevalent genitourinary cancers responsible for about 150,000 deaths per year worldwide. Currently, several treatments, such as endoscopic and open surgery, appended by local or systemic immunotherapy, chemotherapy, and radiotherapy are used to treat this malignancy. However, the differences in treatment outcome among patients suffering from bladder cancer are considered as one of the important challenges. In recent years, cancer stem cells, representing a population of undifferentiated cells with stem-cell like properties, have been eyed as a major culprit for the high recurrence rate in superficial papillary bladder cancer. Cancer stem cells have been reported to be resistant to conventional treatments, such as chemotherapy, radiation, and immunotherapy, which induce selective pressure on tumoral populations resulting in selection and growth of the resistant cells. Therefore, targeting the therapeutic aspects of cancer stem cells in bladder cancer may be promising. In this study, we briefly discuss the biology of bladder cancer and then address the possible relationship between molecular biology of bladder cancer and cancer stem cells. Subsequently, the mechanisms of resistance applied by cancer stem cells against the conventional therapeutic tools, especially chemotherapy, are discussed. Moreover, by emphasizing the biomarkers described for cancer stem cells in bladder cancer, we have provided, described, and proposed targets on cancer stem cells for therapeutic interventions and, finally, reviewed some immunotargeting strategies against bladder cancer stem cells. © 2018 Wiley Periodicals, Inc
Recommended from our members
Mechanical properties of functionally graded hierarchical bamboo structures
This paper presents the results of a series of multi-scale experiments and numerical models concerning the mechanical properties of moso culm functionally graded bamboo structures. On the nano- and microscales, nanoindentation techniques are used to study the local variations in the Young’s moduli of moso culm bamboo cross-sections. These are then incorporated into finite element models in which the actual variations in Young’s moduli are used to model the deformation and fracture of bamboo during fracture toughness experiments. Similarly, the measured gradations in moduli are incorporated into crack bridging models that predict the toughening observed during resistance curve tests. The implications of the results are discussed for the bio-inspired design of structures that mimic the layered, functionally graded structure of bamboo
- …