711 research outputs found
The Longevity Med Summit: insights on healthspan from cell to society
In recent years, there has been a paradigm shift with regards to ageing, challenging its traditional perception as an inevitable and natural process. Researchers have collectively identified hallmarks of ageing, nine of which were initially proposed in 2013 and expanded in 2023 to include disabled macroautophagy, chronic inflammation, and dysbiosis, enhancing our understanding of the ageing process at microscopic, cellular, and system-wide levels. Strategies to manipulate these hallmarks present opportunities for slowing, preventing, or reversing age-related diseases, thereby promoting longevity. The interdependence of these hallmarks underscores the necessity of a comprehensive, systems-based approach to address the complex processes contributing to ageing. As a primary risk factor for various diseases, ageing diminishes healthspan, leading to extended periods of compromised health and multiple age-related conditions towards the end of life. The significant gap between healthspan and lifespan holds substantial economic and societal implications. The inaugural Longevity Med Summit (4–5 May 2023, Cascais, Portugal) provided an international forum to discuss the academic and industry landscape of healthy longevity research, preventive medicine and clinical practice to enhance healthspan
Adult acute epiglottitis
Acute epiglottitis is a disease of rapid onset and progression of symptoms and has been well described in children. The importance of being aware of this diagnosis is to prevent an acute upper airway obstruction that can be potentially fatal. Here we describe two cases of adult acute epiglottitis where the patients had severe symptoms of sorethroat but a normal looking oropharynx
Collagen matrix stiffness influences on fibroblast contraction force
Cell-embedded hydrogel has been widely used as engineered tissue equivalents in biomedical applications. In this study, contraction force in human aortic adventitial fibroblasts seeded within a 3D collagen matrix was quantified by a novel force sensing technique. We demonstrate that contraction forces in cells treated with histamine are regulated by the gel stiffness in a linear manner. These findings provide novel insights for the design of collagen-based biomaterials for tissue engineering and clinical applications
Axon radius estimation with Oscillating Gradient Spin Echo (OGSE) diffusion MRI
The estimation of axon radius provides insights into brain function [1] and could provide progression and classification biomarkers for a number of white matter diseases [2-4]. A recent in silico study [5] has shown that optimised gradient waveforms (GEN) and oscillating gradient waveform spin echo (OGSE) have increased sensitivity to small axon radius compared to pulsed gradient spin echo (PGSE) diffusion MR sequences. In a follow-up study [6], experiments with glass capillaries show the practical feasibility of GEN sequences and verify improved pore-size estimates. Here, we compare PGSE with sine, sine with arbitrary phase, and square wave OGSE (SNOGSE, SPOGSE, SWOGSE, respectively) for axon radius mapping in the corpus callosum of a rat, ex-vivo. Our results suggest improvements in pore size estimates from OGSE over PGSE, with greatest improvement from SWOGSE, supporting theoretical results from [5] and other studies [7-9]
Parametric (On-Design) Cycle Analysis for a Separate-Exhaust Turbofan Engine With Interstage Turbine Burner
Today s modern aircraft is based on air-breathing jet propulsion systems, which use moving fluids as substances to transform energy carried by the fluids into power. Throughout aero-vehicle evolution, improvements have been made to the engine efficiency and pollutants reduction. The major advantages associated with the addition of ITB are an increase in thermal efficiency and reduction in NOx emission. Lower temperature peak in the main combustor results in lower thermal NOx emission and lower amount of cooling air required. This study focuses on a parametric (on-design) cycle analysis of a dual-spool, separate-flow turbofan engine with an Interstage Turbine Burner (ITB). The ITB considered in this paper is a relatively new concept in modern jet engine propulsion. The ITB serves as a secondary combustor and is located between the high- and the low-pressure turbine, i.e., the transition duct. The objective of this study is to use design parameters, such as flight Mach number, compressor pressure ratio, fan pressure ratio, fan bypass ratio, and high-pressure turbine inlet temperature to obtain engine performance parameters, such as specific thrust and thrust specific fuel consumption. Results of this study can provide guidance in identifying the performance characteristics of various engine components, which can then be used to develop, analyze, integrate, and optimize the system performance of turbofan engines with an ITB. Visual Basic program, Microsoft Excel macrocode, and Microsoft Excel neuron code are used to facilitate Microsoft Excel software to plot engine performance versus engine design parameters. This program computes and plots the data sequentially without forcing users to open other types of plotting programs. A user s manual on how to use the program is also included in this report. Furthermore, this stand-alone program is written in conjunction with an off-design program which is an extension of this study. The computed result of a selected design-point engine will be exported to an engine reference data file that is required in off-design calculation
Recovery of end-organs and improved mortality in adult patient on ECMO.
Title: Recovery of End-Organs and Improved Mortality in Adult Patients on ECMO Joshua K Wong, BS1, Vei Shaun Siow, BS1, Thomas N Smith, BS1, Harrison Pitcher, MD2, Linda Bogar, MD2, Hitoshi Hirose, MD2 and Nicholas C Cavarocchi, MD2. 1Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States, 19107 and 2Division of Cardiothoracic Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States, 19107. Body: With increasing use of ECMO in adults, we seek to objectively measure End-Organ recovery and correlate intensive care mortality scores and complications with patient survival. This is a retrospective review of patients who were placed on ECMO from Oct 2010 to Dec 2011. End-Organ function was measured through Pa02/Fi02 ratios, lactate levels, MELD and mortality scores (SAPSII/APACHEII/SOFA). Complications were recorded and analyzed. Twenty-three patients were placed on VA-ECMO and 5 on VV-ECMO. 22 (73%) patients were successfully weaned off ECMO, and 13 (46%) survived to discharge. In 12 patients with liver injury pre-ECMO, the median MELD score was 21 vs 13 post-ECMO (
Forestry and environmental conditions as determinants of pine marten Martes martes occurrence in Norway
The European pine marten Martes martes is often associated with late seral stage coniferous forest stands. Earlier research has indicated that this species may be negatively influenced by clearcutting practices. However, the effects of current clearcutting methods on pine marten occurrence in conjunction with changing environmental conditions are not well known. In this study, we combined four complete years of nationwide data collected during a long-term camera trap (CT) monitoring program in Norway. We employed a multi-scale occupancy model to investigate the relationship of pine marten occurrence to clearcuts (regenerating stands & LE; 10 years old) and forests & GE; 120 years old. We also examined pine marten detection in relation to habitat features (i.e. dominant microsite characteristics) and to varying snow depths and temperatures. We found no relationship between pine marten occurrence and the proportions of old forest and clearcuts at the landscape scale. At the habitat-patch scale, pine marten occurrence was positively associated with the presence of old forest patches and terrain ruggedness, but not with clearcuts & LE; 100 m from sites. At CT sites near clearcuts, the detection probability was negatively correlated with snow depth. In contrast, pine marten occurrence was positively associated with snow depth at CT sites > 100 m from clearcuts. Furthermore, the detection probability increased with temperature and the presence of boulders at CT sites. Boulders may provide important access points for foraging, and cover for resting and predator avoidance. While previous studies indicate that pine martens prefer older forest and avoid clearcuts, the current level and scale of clearcutting in Norway does not appear to influence its occurrence at the landscape scale
Using Diffusion-Diffusion Exchange Spectroscopy to observe diffusion exchange in yeast
The permeability of cell membranes varies significantly across both healthy and diseased tissue, and changes in cell membrane permeability can occur during treatment response in tumours. Measurements of cell membrane permeability could therefore be useful for tumour detection and as biomarkers of treatment response in the clinic. As the diffusion of water across the cell membrane is directly dependent on cell membrane permeability, we have investigated the ability of diffusion-diffusion exchange spectroscopy to quantify the diffusion exchange of water in a suspension of yeast, as a first step towards its application in tumours
Rethinking Client Drift in Federated Learning: A Logit Perspective
Federated Learning (FL) enables multiple clients to collaboratively learn in
a distributed way, allowing for privacy protection. However, the real-world
non-IID data will lead to client drift which degrades the performance of FL.
Interestingly, we find that the difference in logits between the local and
global models increases as the model is continuously updated, thus seriously
deteriorating FL performance. This is mainly due to catastrophic forgetting
caused by data heterogeneity between clients. To alleviate this problem, we
propose a new algorithm, named FedCSD, a Class prototype Similarity
Distillation in a federated framework to align the local and global models.
FedCSD does not simply transfer global knowledge to local clients, as an
undertrained global model cannot provide reliable knowledge, i.e., class
similarity information, and its wrong soft labels will mislead the optimization
of local models. Concretely, FedCSD introduces a class prototype similarity
distillation to align the local logits with the refined global logits that are
weighted by the similarity between local logits and the global prototype. To
enhance the quality of global logits, FedCSD adopts an adaptive mask to filter
out the terrible soft labels of the global models, thereby preventing them to
mislead local optimization. Extensive experiments demonstrate the superiority
of our method over the state-of-the-art federated learning approaches in
various heterogeneous settings. The source code will be released.Comment: 11 pages, 7 figure
Scalable magnet geometries enhance tumour targeting of magnetic nano-carriers
Targeted drug delivery systems aim to increase therapeutic effect within the target tissue or organ, while reducing off-target toxicity associated with systemic delivery. Magnetic drug targeting has been shown to be an effective strategy by manipulating therapeutics inside the body using a magnetic field and an iron oxide carrier. However, the effective targeting range of current magnets limits this method to small animal experiments or superficial parts of the human body. Here we produce clinically translatable magnet designs capable of increasing exposure of tissue to magnetic fields and field gradients, leading to increased carrier accumulation. The iron oxide nanoparticle capturing efficiency was first assessed in vitro using a simple vascular flow system. Secondly, accumulation of these particles, following magnetic targeting, was evaluated in vivo using a range of different magnet designs. We observed that our bespoke magnet produced a 4-fold increase in effective targeting depth when compared to a conventional 1 T disk magnet. Finally, we show that this magnet is readily scalable to human size proportions and has the potential to target 100 nm particles up to a depth of 7 cm at specific locations of human body
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