Regularizing future cosmological singularities with varying speed of light

Cosmological models may result in future singularities. We show that, in the framework of dynamical varying speed of light theories, it is possible to regularize those singularities

Ontology-oriented e-government service integration utilising the semantic web

University of Technology, Sydney. Faculty of Engineering and Information Technology.E-government service integration process has recently become an important research topic in e-government domain since many countries have developed various levels of e-government services. Non-interoperability between government agencies in service delivery implementation and platform posing the technical challenge, and the lack of the formulated modelling framework is the main methodological obstacle on the way of achieving dynamic delivery of integrated e-government services. This research is a study of the problems associated with the integration and delivery of integrated e-government services, and proposes a novel solution to tackle them. We start with investigating the fundamentals of e-government as a field of research to build a sensible argument for the questions investigated by this research, which lead to the exposure of the methodological as well as technological problems with the mechanics of e-government in the areas of service integration and delivery. The outcomes of this study in Chapters 3, 4, 5, 6, and 7 respectively 1) suggests the most practically relevant and technically possible evolutionary pathway to e-government transformation, 2) proposes a modified software engineering process to achieve such transformation, 3) develops an innovative framework for modelling the service integration, 4) proposes an ontology as its knowledgebase, and 5) develops an innovative and intelligent software to support the practice of service integration and delivery. These outcomes collectively result in the introduction of a novel, complete and coherent solution for the abovementioned problems. This research is a cross disciplinary study of software integration engineering frameworks, e-government service delivery platform and semantic web technology, all working to devise the most efficient and robust framework of using semantic web capabilities to enable the delivery of integrated e-government services in an intelligent platform

PVA-Based Nanofibers Containing Chitosan Modified with Graphene Oxide and Carbon Quantum Dot-Doped TiO2 Enhance Wound Healing in a Rat Model

Electrospun nanofibrous constructs based on nanoparticles and biopolymers have recently been used in tissue engineering because of their similarity to the extracellular matrix in nature. In this study, electrospun chitosan-carbon quantum dot-titanium dioxide-graphene oxide (CS-CQD-TiO2-GO) nanofibrous mats were synthesized for use as wound dressings by the electrospinning method. To increase the biodegradation rate and water resistance, the fabricated nanofibrous mats were cross-linked. SEM images showed a uniform and coherent structure of CS-CQD-TiO2-GO nanocomposites and CS-CQD-TiO2-GO electrospun nanofibers mats. FTIR analysis, XRD pattern, SEM mapping, and EDS spectrum demonstrate the accuracy of the synthesis as well as the elemental and chemical structure of the nanofibrous mat. The water contact angle indicated that the nanofibrous mat had a hydrophilic property, which is essential for controlling wound exudates. The tensile strength and elongation tests showed that the nanofibrous mat has suitable mechanical properties for wound dressing, including significant flexibility and strength. Interestingly, antimicrobial testing illustrated that the fabricated nanofibrous mat had antibacterial activity against Gram-negative and Gram-positive bacteria. Appropriate cell viability and cytocompatibility of treated mouse fibroblast NIH3T3 cells with the nanofibrous mat were determined using an MTT assay. The animal study results confirmed the proper potential of the nanofibrous mat in wound dressing applications

In-hospital and six-month outcomes of elderly patients undergoing primary percutaneous coronary intervention for acute st-elevation myocardial infarction

BACKGROUND: Elderly patients constitute a rapidly growing proportion of the population, and hence the increasing rises in the number of patients with ST-segment-elevation myocardial infarction (STEMI). Primary percutaneous coronary intervention (PCI), which is now established as the preferred reperfusion strategy in STEMI patients, has been inadequately investigated in this high-risk group. The aim of the present study was to investigate the in- hospital and 6-month outcomes of primary PCI in elderly patients (� 75 years) with STEMI. METHODS: A total of 100 elderly patients with STEMI including those with cardiogenic shock were included. Primary PCI procedures were performed in a tertiary referral center between 2009 and 2014. In-hospital and 6-month outcomes of patients were recorded and analyzed. RESULTS: The average age of the patients was 79.6 ± 3.8 years (range = 75-90 years) and 27.0 were women. Cardiovascular risk factors and prior events were common. Nearly, half of the patients had three-vessel disease and the left anterior descending artery (LAD) was the most common infarct-related artery. The presence of cardiogenic shock but not the other variables was associated with less anatomic and procedural success (P < 0.001). It was also the major independent predictors of 6-month mortality in the patients aged � 75 years, hazard ratio (HR) = 8.02; 95% confidence interval (CI): 1.75-25.97, P < 0.001. In-hospital mortality was 2.4% in the patients without and 83.0% in those with cardiogenic shock. CONCLUSION: Primary PCI in aged patients could be associated with low complication rates and improved survival if performed in high-volume centers with experienced operators. Considering the very high rate of mortality in patients with cardiogenic shock, there should be measures to treat these patients before the onset of hemodynamic instability. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved

Impella 2.5 in a patient with left main coronary artery occlusion

Short-term assist devices have been indicated in many clinical settings mostly as a bridge to the next step. In this article, we report a case of cardiogenic shock due to acute occlusion of left main coronary artery who was scheduled to be transferred from Iran to Germany for the next treatment (permanent assist device implantation). Impella 2.5 (Abiomed Inc., Danvers, MA, USA), a short-term assist device, made the long distance journey possible.. © 2013

Excitable media in open and closed chaotic flows

We investigate the response of an excitable medium to a localized perturbation in the presence of a two-dimensional smooth chaotic flow. Two distinct types of flows are numerically considered: open and closed. For both of them three distinct regimes are found, depending on the relative strengths of the stirring and the rate of the excitable reaction. In order to clarify and understand the role of the many competing mechanisms present, simplified models of the process are introduced. They are one-dimensional baker-map models for the flow and a one-dimensional approximation for the transverse profile of the filaments.Comment: 14 pages, 16 figure

Lattice instabilities of cubic NiTi from first principles

The phonon dispersion relation of NiTi in the simple cubic B2 structure is computed using first-principles density-functional perturbation theory with pseudopotentials and a plane-wave basis set. Lattice instabilities are observed to occur across nearly the entire Brillouin zone, excluding three interpenetrating tubes of stability along the (001) directions and small spheres of stability centered at R. The strongest instability is that of the doubly degenerate M5' mode. The atomic displacements of one of the eigenvectors of this mode generate a good approximation to the observed B19' ground-state structure.Comment: 11 pages, 3 figure

The predictors of no-reflow phenomenon after primary angioplasty for acute myocardial infarction

Background: No-reflow phenomenon is a serious complication of primary Percutaneous Coronary Intervention (PCI), which may increase the risk of progressive myocardial damage, profound left ventricular dysfunction, and death. Objectives: This study aimed to investigate the incidence of no-reflow phenomenon and its clinical, para-clinical, and angiographic determinants in patients who underwent primary PCI for ST Elevation Myocardial Infarction (STEMI). Patients and Methods: This non-randomized prospective cohort study was conducted on 397 patients in a cardiovascular tertiary care center in Tehran, Iran from April 2012 to April 2014. The inclusion criteria of the study were presenting with acute STEMI of � 12 h duration or having admitted between 12 and 24 hours after onset with symptoms and signs of ongoing ischemia. The participants underwent standard coronary angiography. No-reflow phenomenon was defined as a Thrombolysis In Myocardial Infarction (TIMI) flow � 2 and no presence of spasm, distal embolization, or dissection after completion of the procedure. The association between no-reflow and its determinants was assessed by chi-square, student�s t-test, or Mann�Whitney U test. Logistic regression models were also used for multivariate analysis. P values < 0.05 were considered to be statistically significant. Results: The participants� mean (SD) age was of 59 (12.2) years and female/male ratio was 83/314. The incidence of no-reflow phenomenon was 63 (15.9). Besides, the results of multivariate analysis showed that only thrombus burden, lesion length, time to reperfusion, and type of occlusion had an adjusted association with this phenomenon. Conclusions: The study results suggested that no-reflow phenomenon after primary PCI would be predictable. Thus, preventive measures, such as using distal protective devices or administration of platelet glycoprotein IIb/IIIa antagonists, are advised to be used in high-risk patients. © 2016, Iranian Cardiovascular Research Journal. All rights reserved

A Mutation in HOXA2 Is Responsible for Autosomal-Recessive Microtia in an Iranian Family

Microtia, a congenital deformity manifesting as an abnormally shaped or absent external ear, occurs in one out of 8,000-10,000 births. We ascertained a consanguineous Iranian family segregating with autosomal-recessive bilateral microtia, mixed symmetrical severe to profound hearing impairment, and partial cleft palate. Genome-wide linkage analysis localized the responsible gene to chromosome 7p14.3-p15.3 with a maximum multi-point LOD score of 4.17. In this region, homeobox genes from the HOXA cluster were the most interesting candidates. Subsequent DNA sequence analysis of the HOXA1 and HOXA2 homeobox genes from the candidate region identified an interesting HOXA2 homeodomain variant: a change in a highly conserved amino acid (p.Q186K). The variant was not found in 231 Iranian and 109 Belgian control samples. The critical contribution of HoxA2 for auditory-system development has already been shown in mouse models. We built a homology model to predict the effect of this mutation on the structure and DNA-binding activity of the homeodomain by using the program Modeler 8v2. In the model of the mutant homeodomain, the position of the mutant lysine side chain is consistently farther away from a nearby phosphate group; this altered position results in the loss of a hydrogen bond and affects the DNA-binding activity. © 2008 The American Society of Human Genetics

Modeling Elasticity in Crystal Growth

A new model of crystal growth is presented that describes the phenomena on atomic length and diffusive time scales. The former incorporates elastic and plastic deformation in a natural manner, and the latter enables access to times scales much larger than conventional atomic methods. The model is shown to be consistent with the predictions of Read and Shockley for grain boundary energy, and Matthews and Blakeslee for misfit dislocations in epitaxial growth.Comment: 4 pages, 10 figure