32 research outputs found

    Role of adenosine in the renal responses to contrast medium

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    Role of adenosine in the renal responses to contrast medium. Despite the development of non-ionic radiographic contrast media (CM), CM-induced nephropathy is a clinically important problem in patients with pre-existing renal insufficiency. We examined the effects of non-ionic CM (iohexol) on renal function in conscious dogs with and without renal insufficiency, and evaluated the effects of a non-selective (theophylline), an A1 selective (KW-3902), and an A2 selective adenosine antagonist (KF17837) on the renal responses to CM. In sham-operated group, iohexol (2ml/kg/min for 3min) increased effective renal plasma flow (ERPF) and glomerular filtration rate (GFR), whereas in renal insufficiency group (with subtotal nephrectomy), following transient increases in ERPF and GFR, CM markedly decreased ERPF (-46.5 ± 6.7%) and GFR (-51.2 ± 7.1%). In sham-operated group, theophylline and KF17837 markedly attenuated CM-induced increases in ERPF and GFR, while KW-3902 had no effects on CM-induced increases in ERPF or GFR. In renal insufficiency group, initial increases in ERPF and GFR were blunted by theophylline and KF17837. In contrast, the subsequent decreases in ERPF and GFR were attenuated by theophylline (%ΔERPF, -12.2 ± 3.2% vs. -46.6 ± 6.7%, P < 0.01; %ΔGFR, 4.3 ± 2.5% vs. -51.0 ± 7.1%, P < 0.01), and were completely prevented by KW-3902 (%ΔERPF, 10.8 ± 2.9%; %ΔGFR, 23.8 ± 4.4%), whereas KF17837 aggravated ERPF (-73.3 ± 5.3%) and GFR (-78.4 ± 5.3%). These data indicate that in normal renal function, iohexol elicits renal vasodilation by activating mainly the adenosine A2 receptors. In contrast, in impaired renal function, CM induces both A2 and A1 activation; the former is associated with the initial renal vasodilation, while the latter is responsible for the sustained aggravation of renal hemodynamics

    Application of quantum computing techniques in particle tracking at LHC

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    After the next planned upgrades to the LHC, the luminosity it delivers will more than double, substantially increasing the already large demand on computing resources. Therefore an efficient way to reconstruct physical objects is required. Recent studies show that one of the quantum computing techniques, quantum annealing (QA), can be used to perform particle tracking with efficiency higher than 90% in the high pileup region in the high luminosity environment. The algorithm starts by determining the connection between the hits, and classifies the topological objects with their pattern. The current study aims to improve the pre-processing efficiency in the QA-based tracking algorithm by implementing a graph neural network (GNN), which is expected to efficiently generate the topological object needed for the annealing process. Tracking performance with a different setup of the original algorithm is also studied with data collected by the ATLAS experiment

    Mieap, a p53-Inducible Protein, Controls Mitochondrial Quality by Repairing or Eliminating Unhealthy Mitochondria

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    Maintenance of healthy mitochondria prevents aging, cancer, and a variety of degenerative diseases that are due to the result of defective mitochondrial quality control (MQC). Recently, we discovered a novel mechanism for MQC, in which Mieap induces intramitochondrial lysosome-like organella that plays a critical role in the elimination of oxidized mitochondrial proteins (designated MALM for Mieap-induced accumulation of lysosome-like organelles within mitochondria). However, a large part of the mechanisms for MQC remains unknown. Here, we report additional mechanisms for Mieap-regulated MQC. Reactive oxygen species (ROS) scavengers completely inhibited MALM. A mitochondrial outer membrane protein NIX interacted with Mieap in a ROS-dependent manner via the BH3 domain of NIX and the coiled-coil domain of Mieap. Deficiency of NIX also completely impaired MALM. When MALM was inhibited, Mieap induced vacuole-like structures (designated as MIV for Mieap-induced vacuole), which engulfed and degraded the unhealthy mitochondria by accumulating lysosomes. The inactivation of p53 severely impaired both MALM and MIV generation, leading to accumulation of unhealthy mitochondria. These results suggest that (1) mitochondrial ROS and NIX are essential factors for MALM, (2) MIV is a novel mechanism for lysosomal degradation of mitochondria, and (3) the p53-Mieap pathway plays a pivotal role in MQC by repairing or eliminating unhealthy mitochondria via MALM or MIV generation, respectively

    A scoping review of eye-tracking metrics as an indicator of negative mental health-related outcomes and its possible applicability in remote work situations

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    Objectives: This scoping review aims to examine the existing use of eye-tracking technologies being applied to measure negative mental health-related outcomes. The review was guided by the following questions: 1) What eye-tracking methods are currently in use?; and 2) What type of negative mental health-related outcomes are these methods being applied to for estimation? Results will be evaluated to determine their prospective implementation in remote work as a mental health indicator. Methods: A scoping review was conducted in order to collect data from a range of sources and evaluate many distinct research methodologies. A scoping review was chosen for this study to widely report on the research currently being conducted, rather than answer a specific question from a focused set of evidence. On May 26, 2022, a systematic search of the scientific literature was conducted to identify any eye-tracking methods that have been used to measure stress and anxiety. Results: Out of an initial 5,356 eligible articles, a total of 14 articles were included in this scoping review. Estimation outcomes also ranged from various mental health-related outcomes with the most common outcome relating to stress and fatigue. Other outcomes included sleepiness, drowsiness, arousal, frustration, hypervigilance, defensive state, peritraumatic dissociation, and anxiety. Conclusions: Preliminary results show a very promising connection between eye metrics and negative mental health-related outcomes, which are very relevant to workplace mental health as well

    Crystal plasticity analysis of fatigue crack initiation site considering crystallographic orientation in Ti–22V–4Al alloy

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    In this study, plane bending fatigue tests were conducted on Ti–22V–4Al alloy, a β-type titanium alloy, to examine the fatigue crack initiation behavior in detail. In addition, the prediction of fatigue crack initiation points was investigated from the perspectives of the Schmidt factor (SF) and crystal plasticity finite element method (CP-FEM). The slip system contributing to fatigue crack initiation can be accurately predicted by assessing the magnitude relationship of SF. Also, this prediction is already indicated in a lot of paper by using out of component of slip activity. However, the location where the fatigue crack will occur can be not estimated by SF on polycrystalline. Therefore, prediction of grains where fatigue cracks will occur could be achieved with high accuracy by constructing a CP-FEM that considers the mechanical interaction of polycrystals and grain boundary. Utilizing advanced methodologies such as CP-FEM and numerical calculation techniques, it is strictly investigated that the factors influencing fatigue crack initiation in polycrystalline materials. Our research concluded the understanding of fatigue crack initiation on polycrystal grains by considering the mechanical interaction of polycrystals and grain boundary

    Structure of AmpC β-lactamase (AmpCD) from an Escherichia coli clinical isolate with a tripeptide deletion (Gly286-Ser287-Asp288) in the H10 helix

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    The structure of AmpC β-lactamase (AmpCD) from E. coli with a tripeptide deletion (Gly286-Ser287-Asp288) is reported

    Application of quantum computing techniques in particle tracking at LHC

    No full text
    In the near future, the LHC detector will deliver higher luminosity, causing the demand on large amount of computing resources. Therefore an efficient way to reconstruct physical objects are required. Recent studies showed that one of the quantum computing techniques, quantum annealing (QA), can be used to perform the particle tracking with efficiency higher than 90% in the high pileup region in the high luminosity environment. The algorithm starts from determining the connection between the hits, and classify the topological objects with their pattern. The current study aims to improve the pre-processing efficiency in the QA-based tracking algorithm by implementing a graph neural network (GNN), which is expected to efficiently generate the topological object needed for the annealing process. Moreover, the tracking performances with data collected from ATLAS experiment are also included

    Characteristics of Physiological Parameters of Japanese Black Calves Relate to Carcass Weight

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    This study aimed to identify the growth performance and blood factors associated with carcass weight in Japanese Black calves based on 675 performance tests and field carcass records. We measured the body weight, withers height, and chest girth at the start of fattening age (approximately 8&ndash;10 months) and analyzed eight blood factors, including vitamins and metabolites. Single- and two-trait animal models were used to estimate the heritability and genetic correlations. The heritability estimates for growth performance were moderate to high (ranging from 0.48 to 0.74), and those for blood metabolites were low to moderate (ranging from 0.19 to 0.51). Estimates for genetic correlations of carcass or body weight with body weight, withers height, and chest girth were high (ranging from 0.42 to 0.80). The body weight and withers height at 8 months of age are possibly closely related to the final carcass weight. The blood metabolites associated with body weight were vitamin E in steers (castrated males) and &beta;-carotene in heifers. Our findings indicate that body measurements and blood metabolites measured during the growing period could be used to determine the nutritional and physiological status of cattle as well as predict carcass weight

    Imaging of monochromatic beams by measuring secondary electron bremsstrahlung for carbon-ion therapy using a pinhole x-ray camera

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    A feasibility study on the imaging of monochromatic carbon-ion beams for carbon-ion therapy was performed. The evaluation was based on Monte Carlo simulations and beam-irradiation experiments, using a pinhole x-ray camera, which measured secondary electron bremsstrahlung (SEB). The simulation results indicated that the trajectories of the carbon-ion beams with injection energies of 278, 249 and 218 MeV/u in a water phantom, were clearly imaged by measuring the SEB with energies from 30 to 60 keV, using a pinhole camera. The Bragg-peak positions for these three injection energies were located at the positions where the ratios of the counts of SEB acquisitions to the maximum counts were approximately 0.23, 0.26 and 0.29, respectively. Moreover, we experimentally demonstrated that it was possible to identify the Bragg-peak positons, at the positions where the ratios coincided with the simulation results. However, the estimated Bragg-peak positions for the injection energies of 278 and 249 MeV/u were slightly deeper than the expected positions. In conclusion, for both the simulations and experiments, we found that the 25-mm shifts in the Bragg-peak positions can be observed by this method
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