665 research outputs found

    Personalized medicine approach in mycobacterial disease

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    AbstractMycobacterial diseases are a group of illnesses that cause a considerable number of deaths throughout the world, regardless of years of public health control efforts. Personalized medicine is a new but rapidly advancing field of healthcare. Personalized medicine in the field of mycobacteriology may be applied in the different levels of management such as prevention, diagnosis, treatment and prognosis. A genetic predisposition and a protein dysfunction study are recommended to tailor an individual approach in mycobacterial diseases

    Analysis of hydrodynamic drag forces acting on suspended fine particle in porous media

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    An important class of flow and transport problems occurring in porous media involves the interactions between suspended fine particles and the moving fluid at Stokes limit. Historically, due to the complicated geometries of porous media, researchers have had to resort to simplifying assumptions to conceptualize the underlying physics. However, the advent of high performance computing, in recent decades, has made it possible to vigorously investigate this problem at the streamline scale level. In this work, the flow problem is solved by means of a finite-element model. The simulations results are used to compute the drag forces experienced by suspended fine particles. The drag force distributions experienced by suspended fine particles of different sizes in various compact granular porous media – ordered (simple cubic (SC), body-centered cubic (BCC), face-centered cubic (FCC)) and monodisperse disordered packs are reported and discussed. It is concluded that, overall, the trends of the drag force distribution in the face centered cubic (FCC) pack are the closest to those of the disordered pack, despite the considerable difference in their porosity values (~10). Moreover, analyzing the pressure and viscous fractions of the hydrodynamic force experienced by each individual fine particle, it is concluded that the locations where the largest deviations from the Stokes law occur in all the domains have the same spatial characteristic, such as close proximity to grain-to-grain contact points. Similar spatial characteristic is also seen regarding the locations of the smallest and the largest ranges of the drag force in all the different granular domains. It is also seen that the polar circulation zones, which only forms in the SC and the BCC packs, causes unexpected trends in the drag force distributions of particle, which are fully or partially inside these zones. Furthermore, the simulation results are compared with the drag force predictions obtained via the Happel model. The results of the semi-analytical approach, more or less, capture the trend of the drag force distribution obtained via simulation in the FCC and ordered packs, however, the semi-analytical results can significantly underestimate the drag force experienced by the suspended, fine particles.The influence of neighboring suspended fine particles on each other is also briefly analyzed using our direct numerical approach

    Exosomes and Exosomal miRNA in Respiratory Diseases

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    Exosomes are nanosized vesicles released from every cell in the body including those in the respiratory tract and lungs. They are found in most body fluids and contain a number of different biomolecules including proteins, lipids, and both mRNA and noncoding RNAs. Since they can release their contents, particularly miRNAs, to both neighboring and distal cells, they are considered important in cell-cell communication. Recent evidence has shown their possible importance in the pathogenesis of several pulmonary diseases. The differential expression of exosomes and of exosomal miRNAs in disease has driven their promise as biomarkers of disease enabling noninvasive clinical diagnosis in addition to their use as therapeutic tools. In this review, we summarize recent advances in this area as applicable to pulmonary diseases

    Health and Economy in COVID-19 Era: A Plan for Reconstituting Long-Term Economic Security

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    © Copyright © 2020 Allen and Mirsaeidi. COVID-19 is a rapidly evolving pandemic, which represents a multifaceted global threat. Given the economic consequences, most researchers agree that social distancing measures are an effective strategy relative to the cost. Previous studies indicate that community size as well as viral population risk groups should be considered in forming an effective targeted social distancing strategy. The resultant delay in the occurrence of infections in order to support vaccine development has been shown to be an effective policy. However, a return to normalcy from the current situation would require policy intervention that transforms the American economy along with continued targeted social distancing and the use of medical science as a tool to facilitate gradual personal interactions of low-risk individuals. We believe that the adoption of rapid IgG testing would be best suitable for widespread population-level screening as part of a comprehensive plan for incrementally rebuilding the in-person workforce. As such, this crisis represents an opportunity for the United States to increase automation of the manufacturing sector, shrink supply chains, and create higher-level jobs in order to reduce the dependency on other countries for critical supplies. This economic transition to better utilize technology along with reconstruction of the workforce could improve the standard of living for many Americans as well as better prepare the US for future pandemics

    Challenges, advances and future directions in protection of hybrid AC/DC microgrids

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    Hybrid microgrids which consist of AC and DC subgrids interconnected by power electronic interfaces have attracted much attention in recent years. They not only can integrate the main benefits of both AC and DC configurations, but also can reduce the number of converters in connection of Distributed Generation (DG) sources, Energy Storage Systems (ESSs) and loads to AC or DC buses. In this paper, the structure of hybrid microgrids is discussed, and then a broad overview of the available protection devices and approaches for AC and DC subgrids is presented. After description, analysis and classification of the existing schemes, some research directions including communication infrastructures, combined control and protection schemes, and promising devices for the realisation of future hybrid AC/DC microgrids are pointed out

    A novel approach for protection of radial and meshed microgrids

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    During grid-connected operation mode of microgrids, since the main grid provides a large short-circuit current to the fault point, the protection can be performed by the conventional protective devices, but in islanded mode, fault currents are drastically lower than those of grid-connected mode. Hence, employment of traditional overcurrent-based protective devices in micro-grids is no longer valid and some alternative protection schemes should be developed. This paper presents a micro-grid protection scheme based on positive-sequence component using Phasor Measurement Units (PMUs) and a Central Protection Unit (CPU). The salient feature of the proposed scheme in comparison with the previous works is that it has the ability to protect both radial and meshed micro-grids against different types of faults. Furthermore, since the CPU is capable of updating its pickup values (upstream and downstream equivalent positive-sequence impedances of each line) after the first change in the micro-grid configuration (such as transferring from grid-connected to islanded mode and or disconnection of a line, bus, or DER either in grid-connected mode or in islanded mode), it can protect micro-grid against subsequent faults. In order to verify the effectiveness of the proposed scheme and the CPU, several simulations have been undertaken by using DIgSILENT PowerFactory and MATLAB software packages

    Perspectives on the health effects of hurricanes: A review and challenges

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    Hurricanes are devastating natural disasters which dramatically modify the physical landscape and alter the socio-physical and biochemical characteristics of the environment, thus exposing the affected communities to new environmental stressors, which persist for weeks to months after the hurricane. This paper has three aims. First, it conceptualizes potential direct and indirect health effects of hurricanes and provides an overview of factors that exacerbate the health effects of hurricanes. Second, it summarizes the literature on the health impact of hurricanes. Finally, it examines the time lag between the hurricane (landfall) and the occurrence of diseases. Two major findings emerge from this paper. Hurricanes are shown to cause and exacerbate multiple diseases, and most adverse health impacts peak within six months following hurricanes. However, chronic diseases, including cardiovascular disease and mental disorders, continue to occur for years following the hurricane impact

    Intelligent fault location in MTDC networks by recognising patterns in hybrid circuit breaker currents during fault clearance process

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    In this paper, a novel, learning-based method for accurate location of faults in MTDC networks is proposed. By assessing the DC circuit breaker currents during the fault clearance process, a pattern recognition approach is adopted from which the fault location is estimated. The implementation of the algorithm is allocated into three main stages, where similarity coefficients and weighted averaging functions (incorporating exponential kernels) are utilized. For the proposed algorithm, only a short-time window of data (equal to 6 ms) is required. The performance of the proposed method is assessed through detailed transient simulation using verified MATLAB/Simulink models. Training patterns have been retrieved by applying a series of different faults within an MTDC network. Simulation and experimental results revealed that the proposed scheme i) can reliably determine the type of fault ii) can accurately estimate the fault location (including the cases of highly resistive faults) and iii) is practically feasible
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