The fat mouse: a powerful genetic model to study elevated plasminogen activator inhibitor 1 in obesity/NIDDM

Plasminogen activator inhibitor-1 is elevated in obesity and may be a risk factor for obesity/NIDDM related cardiovascular disease. In spite of this, little is known about the tissue and cellular origin of elevated PAI-1 in obesity or of the mediators and molecular mechanisms that regulate it. We have begun to systematically address these issues using genetically obese (ob/ob, db/db) mice. Plasma PAI-1 levels were 5-fold higher in obese mice compared to their lean counterparts. Subsequent RT-PCR and in situ hybridization studies suggest that the increased plasma PAI-1 originates primarily from the adipocyte in response to chronically elevated levels of tumor necrosis factor-alpha (TNF-alpha), insulin, and transforming growth factor-beta (TGF-beta). Thus, the signals and mechanisms that lead to elevated plasma PAI-1 observed in obesity are complex, and appear to involve interactions between multiple mediators and the adipose tissue itself.     

Characterization of medical waste from hospitals in Tabriz, Iran

Medical waste has not received enough attention in recent decades in Iran, as is the case in most economically developing countries. Medical waste is still handled and disposed of together with domestic waste, creating great health risks to health-care stuff, municipal workers, the public, and the environment. A fundamental prerequisite for the successful implementation of any medical waste management plan is the availability of sufficient and accurate information about the quantities and composition of the waste generated. The objectives of this study were to determine the quantity, generation rate, quality, and composition of medial waste generated in the major city northwest of Iran in Tabriz. Among the 25 active hospitals in the city, 10 hospitals of different size, specializations, and categories (i.e., governmental, educational, university, private, non-governmental organization (NGO), and military) were selected to participate in the survey. Each hospital was analyzed for a week to capture the daily variations of quantity and quality. The results indicated that the average (weighted mean) of total medical waste, hazardous-infectious waste, and general waste generation rates in Tabriz city is 3.48, 1.039 and, 2.439 kg/bed-day, respectively. In the hospital waste studied, 70.11% consisted of general waste, 29.44% of hazardous-infectious waste, and 0.45% of sharps waste (total hazardous-infectious waste 29.89%). Of the maximum average daily medical waste, hazardous-infectious waste, and general waste were associated with N.G.O and private hospitals, respectively. The average composition of hazardous-infectious waste was determined to be 35.72% plastics, 20.84% textiles, 16.70% liquids, 11.36% paper/cardboard, 7.17% glass, 1.35% sharps, and 6.86% others. The average composition of general waste was determined to be 46.87% food waste, 16.40% plastics, 13.33% paper/cardboard, 7.65% liquids, 6.05% textiles, 2.60% glass, 0.92% metals, and 6.18% others. The average bulk densities of total medical waste, hazardous-infectious waste, and general waste were determined to be 99.58, 96.16 and 101.26 kg/m³, respectively. Significant differences were observed between the medical waste characteristics of the hospitals studied here and those reported in other studies. In conclusion, the characteristics of generated medical waste, current environmental problems and strict budgets necessitate that the implementation of efficient management, training, and segregation program be top priorities if we are to minimize the treatment and disposal costs and reduce the risks of hazardous-infectious waste in Tabriz city.     

Femtosecond Ti: Sa ultra short-pulse laser irradiation effects on the properties and morphology of the zirconia surface after ageing

Femtosecond pulses from a Ti:Sapphire laser were used to irradiate specimens of yttria-stabilised (35% mol) tetragonal zirconia (Y-TZP) with the purpose of studying the effects of the irradiations on their surface properties and morphology after ageing. Zirconia disks were divided into eight groups (n = 32) according to their surface treatment and subsequent ageing: Control: no treatment; sandblasting: Al₂O₃ sandblasting 50 μm; and ultrashort laser pulses irradiation with 25 μJ pulses, considering two different scanning steps based on the width between two grooves. These groups were duplicated and submitted to ageing. The surfaces were analysed using scanning electron microscopy (SEM), and X-ray diffraction. A finite element analysis, a biaxial flexure test, as well as fractographic and Weibull analyses, were performed. The strengths of the disks were statistically different for the treatment factor, and the principal stresses seemed to be concentrated at the centre of the specimens, as predicted by the computer simulations. Ageing decreased the strengths for all groups and increased the Weibull modulus for the laser group with the 40 μm-width between two grooves. The sandblasting group presented the highest monoclinic phase peak. Although the most significant strength was found within the sandblasting group, the phase transformation was favourable to the laser groups. The Weibull modulus was higher for the laser group with the 60 μm-width between two grooves, confirming the highest homogeneity of its failure distribution. Regardless of the surface treatment, strength was decreased with ageing in all groups. The femtosecond Ti:Sa ultra-short pulse laser irradiation can be suggested as an alternative to the gold standard sandblasting in long-term Y-TZP zirconia rehabilitations, such as crowns and veneers.     

Corrigendum to “A model to control environmental performance of project execution process based on greenhouse gas emissions using earned value management” [Int. J. Proj. Manag. 36 (3) (April 2018) 397-413]

Abstract was revised as follows:In response to recent climate change, which is believed to be attributed to the release of greenhouse gas (GHG) emissions, many countries are placing CO₂ abatement programs such as carbon tax and cap-and-trade. Projects do have a significant share in GHGs and therefore their environmental performance, like their schedule and cost performance, should be monitored and controlled. Although many large projects would pass an environmental assessment in the project evaluation phase, the issue of environmental performance monitoring during the project execution phase has not been addressed in project management methodologies. The objective of this paper is to develop a model to estimate project GHG emissions, and to measure project GHG performance using the developed metrics, which can be used at any point in time over the life of a project. A comprehensive study is conducted to collect information on GHG emission factors of various project activity data (such as material use, energy and fuel consumption, transportation, etc.), and a user form interface is developed to calculate the total GHG of an activity. Also, a breakdown structure is proposed which supports managing all the project GHG accounts. The monitoring and control model is formulated based on the logic used in earned value management (EVM) methodology. The proposed model is then implemented to a work package of a real construction project. The results present the project initial GHG plan and show that the model is able to calculate project GHG variance by the reporting date and predict project final GHG based on a project GHG performance index. The method presented in this paper is general and can be applied to any type of projects in an organization that aims to reduce its carbon footprint. The same structure can be applied to monitor and control any other environmental impact associated with project execution process.     

Predicting catastrophic temperature changes based on past events via a CNN-LSTM regression mechanism

Neural Computing and Applications - The modelling and prediction of extreme temperature changes in enclosed compartments is a domain with applications ranging from residential fire alarms,...     

Mechanical Cues Regulating Proangiogenic Potential of Human Mesenchymal Stem Cells through YAP‐Mediated Mechanosensing

Stem cells secrete trophic factors that induce angiogenesis. These soluble factors are promising candidates for stem cell–based therapies, especially for cardiovascular diseases. Mechanical stimuli and biophysical factors presented in the stem cell microenvironment play important roles in guiding their behaviors. However, the complex interplay and precise role of these cues in directing pro‐angiogenic signaling remain unclear. Here, a platform is designed using gelatin methacryloyl hydrogels with tunable rigidity and a dynamic mechanical compression bioreactor to evaluate the influence of matrix rigidity and mechanical stimuli on the secretion of pro‐angiogenic factors from human mesenchymal stem cells (hMSCs). Cells cultured in matrices mimicking mechanical elasticity of bone tissues in vivo show elevated secretion of vascular endothelial growth factor (VEGF), one of representative signaling proteins promoting angiogenesis, as well as increased vascularization of human umbilical vein endothelial cells (HUVECs) with a supplement of conditioned media from hMSCs cultured across different conditions. When hMSCs are cultured in matrices stimulated with a range of cyclic compressions, increased VEGF secretion is observed with increasing mechanical strains, which is also in line with the enhanced tubulogenesis of HUVECs. Moreover, it is demonstrated that matrix stiffness and cyclic compression modulate secretion of pro‐angiogenic molecules from hMSCs through yes‐associated protein activity.