15 research outputs found
Remaining Useful Life Modelling with an Escalator Health Condition Analytic System
The refurbishment of an escalator is usually linked with its design life as
recommended by the manufacturer. However, the actual useful life of an
escalator should be determined by its operating condition which is affected by
the runtime, workload, maintenance quality, vibration, etc., rather than age
only. The objective of this project is to develop a comprehensive health
condition analytic system for escalators to support refurbishment decisions.
The analytic system consists of four parts: 1) online data gathering and
processing; 2) a dashboard for condition monitoring; 3) a health index model;
and 4) remaining useful life prediction. The results can be used for a)
predicting the remaining useful life of the escalators, in order to support
asset replacement planning and b) monitoring the real-time condition of
escalators; including alerts when vibration exceeds the threshold and signal
diagnosis, giving an indication of possible root cause (components) of the
alert signal.Comment: 14 pages, 12 figures, 7 table
An Algorithm for Modelling Escalator Fixed Loss Energy for PHM and sustainable energy usage
Prognostic Health Management (PHM) is designed to assess and monitor the
health status of systems, anticipate the onset of potential failure, and
prevent unplanned downtime. In recent decades, collecting massive amounts of
real-time sensor data enabled condition monitoring (CM) and consequently,
detection of abnormalities to support maintenance decision-making.
Additionally, the utilization of PHM techniques can support energy
sustainability efforts by optimizing energy usage and identifying opportunities
for energy-saving measures. Escalators are efficient machines for transporting
people and goods, and measuring energy consumption in time can facilitate PHM
of escalators. Fixed loss energy, or no-load energy, of escalators denotes the
energy consumption by an unloaded escalator. Fixed loss energy varies over time
indicating varying operating conditions. In this paper, we propose to use
escalators' fixed loss energy for PHM. We propose an approach to compute daily
fixed loss energy based on energy consumption sensor data. The proposed
approach is validated using a set of experimental data. The advantages and
disadvantages of each approach are also presented, and recommendations are
given. Finally, to illustrate PHM, we set up an EWMA chart for monitoring the
fixed loss over time and demonstrate the potential in reducing energy costs
associated with escalator operation
Antidromic vasodilatation and the migraine mechanism
Despite the fact that an unprecedented series of new discoveries in neurochemistry, neuroimaging, genetics and clinical pharmacology accumulated over the last 20 years has significantly increased our current knowledge, the underlying mechanism of the migraine headache remains elusive. The present review article addresses, from early evidence that emerged at the end of the nineteenth century, the role of ‘antidromic vasodilatation’ as part of the more general phenomenon, currently defined as neurogenic inflammation, in the unique type of pain reported by patients suffering from migraine headaches. The present paper describes distinctive orthodromic and antidromic properties of a subset of somatosensory neurons, the vascular- and neurobiology of peptides contained in these neurons, and the clinical–pharmacological data obtained in recent investigations using provocation tests in experimental animals and human beings. Altogether, previous and recent data underscore that antidromic vasodilatation, originating from the activation of peptidergic somatosensory neurons, cannot yet be discarded as a major contributing mechanism of the throbbing head pain and hyperalgesia of migraine
A Phase II
Aims: CONCERT-HF is an NHLBI-sponsored, double-blind, placebo-controlled, Phase II trial designed to determine whether treatment with autologous bone marrow-derived mesenchymal stromal cells (MSCs) and c-kit positive cardiac cells (CPCs), given alone or in combination, is feasible, safe, and beneficial in patients with heart failure (HF) caused by ischaemic cardiomyopathy.
Methods and results: Patients were randomized (1:1:1:1) to transendocardial injection of MSCs combined with CPCs, MSCs alone, CPCs alone, or placebo, and followed for 12 months. Seven centres enrolled 125 participants with left ventricular ejection fraction of 28.6 ± 6.1% and scar size 19.4 ± 5.8%, in New York Heart Association class II or III. The proportion of major adverse cardiac events (MACE) was significantly decreased by CPCs alone (-22% vs. placebo, P = 0.043). Quality of life (Minnesota Living with Heart Failure Questionnaire score) was significantly improved by MSCs alone (P = 0.050) and MSCs + CPCs (P = 0.023) vs. placebo. Left ventricular ejection fraction, left ventricular volumes, scar size, 6-min walking distance, and peak oxygen consumption did not differ significantly among groups.
Conclusions: This is the first multicentre trial assessing CPCs and a combination of two cell types from different tissues in HF patients. The results show that treatment is safe and feasible. Even with maximal guideline-directed therapy, both CPCs and MSCs were associated with improved clinical outcomes (MACE and quality of life, respectively) in ischaemic HF without affecting left ventricular function or structure, suggesting possible systemic or paracrine cellular mechanisms. Combining MSCs with CPCs was associated with improvement in both these outcomes. These results suggest potential important beneficial effects of CPCs and MSCs and support further investigation in HF patients
Non-coding RNAs in Cardiac Regeneration
Cardiovascular disease is a leading cause of death worldwide, and with the dramatically increasing numbers of heart failure patients in the next 10 years, mortality will only increase [1]. For patients with end-stage heart failure, heart transplantation is the sole option. Regrettably, the number of available donor hearts is drastically lower than the number of patients waiting for heart transplantation. Despite evidence of cardiomyocyte renewal in adult human hearts, regeneration of functional myocardium after injury can be neglected. The limited regenerative capacity due to inadequate proliferation of existing cardiomyocytes is insufficient to repopulate areas of lost myocardium [2]. As a solution, the hypothesis that adult stem cells could be employed to generate functional cardiomyocytes was proposed. One of the early studies that supported this hypothesis involved direct injection of hematopoietic c-kit-positive cells derived from bone marrow into the infarcted heart [3]. However, in sharp contrast, more recent evidence emerged demonstrating that these hematopoietic stem cells only differentiate into cells down the hematopoietic lineage rather than into cardiomyocytes [4, 5], and the focus shifted towards stem cells residing in the heart, called cardiac progenitor cells. These CPCs were extracted and injected into the myocardium to regenerate the heart [6]. In recent years, over 80 pre-clinical studies employing cardiac stem cells in vivo in large and small animals to evaluate the effect on functional parameters were systematically reviewed, identifying differences between large and small animals [7]. Despite the positive outcome of these stem cell therapies on functional parameters, c-kit-positive cardiac progenitor cells were shown to contribute minimally to the generation of functional cardiomyocytes [8, 9]. This heavily debated topic is summarized concisely by van Berlo and Molkentin [10]. Recently, single-cell sequencing and genetic lineage tracing of proliferative cells in the murine heart in both homeostatic and regenerating conditions did not yield a quiescent cardiac stem cell population or other cell types that support transdifferentiation into cardiomyocytes, nor did it support proliferation of cardiac myocytes [11, 12]. Now, the focus is shifting towards exploiting the limited regenerative capacity of the cardiomyocytes themselves, by re-activating proliferation of existing cardiomyocytes through dedifferentiation, reentry into the cell cycle, and cytokinesis. This process is the new focus of research to promote cardiac regeneration, and can be controlled on multiple levels, including cell-cycle manipulation, reprogramming, small molecules, extra-cellular matrix (ECM), proteins, and RNA regulation [13]