4,216 research outputs found

    Smart Roadside System for Driver Assistance and Safety Warnings: Framework and Applications

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    The use of newly emerging sensor technologies in traditional roadway systems can provide real-time traffic services to drivers through Telematics and Intelligent Transport Systems (ITSs). This paper introduces a smart roadside system that utilizes various sensors for driver assistance and traffic safety warnings. This paper shows two road application models for a smart roadside system and sensors: a red-light violation warning system for signalized intersections, and a speed advisory system for highways. Evaluation results for the two services are then shown using a micro-simulation method. In the given real-time applications for drivers, the framework and certain algorithms produce a very efficient solution with respect to the roadway type features and sensor type use

    Comparable hematologic and nutritional outcomes of proximal gastrectomy with double-tract reconstruction compared with total gastrectomy for early gastric cancer in the upper stomach

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    Department of MedicinePotential benefits of proximal gastrectomy in terms of hematologic and nutritional outcomes over total gastrectomy have been theoretically suggested in several studies. However, no proven evidences for the hematological and nutritional outcomes have been demonstrated. Thus, we compared hematologic and nutritional outcomes after proximal gastrectomy with double-tract reconstruction with those after total gastrectomy. From September 2014 to December 2015, there were 80 patients underwent minimally invasive surgery, proximal gastrectomy or total gastrectomy, for stage I gastric cancer. We divided patients into two groups: proximal gastrectomy group, 38 patients underwent proximal gastrectomy with double-tract reconstruction and total gastrectomy group, 42 patients underwent total gastrectomy. We retrospectively analyzed clinicopathologic, hematologic, and nutritional features. We found no significant differences in hematologic outcomes. Change of hemoglobin level and cumulative incidence of iron deficiency anemia between the two groups were similar (p = 0.250 and 0.971, respectively) with a median follow up period of 24 months (range 18 – 30 months) after surgery. Cumulative incidence of vitamin B12 deficiency did not significantly differ between the proximal gastrectomy group and the total gastrectomy group (p = 0.087). There was no significant difference in the patients’ BMI changes from baseline between the proximal gastrectomy group and the total gastrectomy group (p = 0.591). In the nutritional features, there were no statistically significant differences. This study showed that proximal gastrectomy with double-tract reconstruction and total gastrectomy have no statistically different outcomes in terms of hematologic and nutritional aspect, especially in emergence of iron deficiency and vitamin B12 deficiency anemia. In conclusion, for patients with gastric cancer located in upper third of the stomach, proximal gastrectomy with double-tract reconstruction can be considered as an alternative option with comparable outcomes of total gastrectomy, if oncological safety is assured.open석

    Catalytic enzymes are active matter

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    Using a microscopic theory to analyze experiments, we demonstrate that enzymes are active matter. Superresolution fluorescence measurements—performed across four orders of magnitude of substrate concentration, with emphasis on the biologically relevant regime around or below the Michaelis–Menten constant—show that catalysis boosts the motion of enzymes to be superdiffusive for a few microseconds, enhancing their effective diffusivity over longer timescales. Occurring at the catalytic turnover rate, these fast ballistic leaps maintain direction over a duration limited by rotational diffusion, driving enzymes to execute wormlike trajectories by piconewton forces performing work of a few kBT against viscosity. The boosts are more frequent at high substrate concentrations, biasing the trajectories toward substrate-poor regions, thus exhibiting antichemotaxis, demonstrated here experimentally over a wide range of aqueous concentrations. Alternative noncatalytic, passive mechanisms that predict chemotaxis, cross-diffusion, and phoresis, are critically analyzed. We examine the physical interpretation of our findings, speculate on the underlying mechanism, and discuss the avenues they open with biological and technological implications. These findings violate the classical paradigm that chemical reaction and motility are distinct processes, and suggest reaction–motion coupling as a general principle of catalysis.11sciescopu

    Enzyme leaps fuel antichemotaxis

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    There is mounting evidence that enzyme diffusivity is enhanced when the enzyme is catalytically active. Here, using superresolution microscopy [stimulated emission-depletion fluorescence correlation spectroscopy (STED-FCS)], we show that active enzymes migrate spontaneously in the direction of lower substrate concentration (???antichemotaxis???) by a process analogous to the run-and-tumble foraging strategy of swimming microorganisms and our theory quantifies the mechanism. The two enzymes studied, urease and acetylcholinesterase, display two families of transit times through subdiffraction-sized focus spots, a diffusive mode and a ballistic mode, and the latter transit time is close to the inverse rate of catalytic turnover. This biochemical information-processing algorithm may be useful to design synthetic self-propelled swimmers and nanoparticles relevant to active materials. Executed by molecules lacking the decision-making circuitry of microorganisms, antichemotaxis by this run-and-tumble process offers the biological function to homogenize product concentration, which could be significant in situations when the reactant concentration varies from spot to spot

    High affinity binding of H3K14ac through collaboration of bromodomains 2, 4 and 5 is critical for the molecular and tumor suppressor functions of PBRM1.

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    Polybromo-1 (PBRM1) is an important tumor suppressor in kidney cancer. It contains six tandem bromodomains (BDs), which are specialized structures that recognize acetyl-lysine residues. While BD2 has been found to bind acetylated histone H3 lysine 14 (H3K14ac), it is not known whether other BDs collaborate with BD2 to generate strong binding to H3K14ac, and the importance of H3K14ac recognition for the molecular and tumor suppressor function of PBRM1 is also unknown. We discovered that full-length PBRM1, but not its individual BDs, strongly binds H3K14ac. BDs 2, 4, and 5 were found to collaborate to facilitate strong binding to H3K14ac. Quantitative measurement of the interactions between purified BD proteins and H3K14ac or nonacetylated peptides confirmed the tight and specific association of the former. Interestingly, while the structural integrity of BD4 was found to be required for H3K14ac recognition, the conserved acetyl-lysine binding site of BD4 was not. Furthermore, simultaneous point mutations in BDs 2, 4, and 5 prevented recognition of H3K14ac, altered promoter binding and gene expression, and caused PBRM1 to relocalize to the cytoplasm. In contrast, tumor-derived point mutations in BD2 alone lowered PBRM1\u27s affinity to H3K14ac and also disrupted promoter binding and gene expression without altering cellular localization. Finally, overexpression of PBRM1 variants containing point mutations in BDs 2, 4, and 5 or BD2 alone failed to suppress tumor growth in a xenograft model. Taken together, our study demonstrates that BDs 2, 4, and 5 of PBRM1 collaborate to generate high affinity to H3K14ac and tether PBRM1 to chromatin. Mutations in BD2 alone weaken these interactions, and this is sufficient to abolish its molecular and tumor suppressor functions

    Measurement of epigenetic alterations from patient’s tissues in myoma, adenomyoma and endometriosis

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    Background: Myoma, adenomyoma, and endometriosis are estrogen-dependent gynecologic diseases and result in reproductive dysfunction and pelvic pain in women. However, these gynecologic diseases have a complex and poorly understood etiology, involving both genetic and environmental factors. Epigenetic alterations, heritable changes that can modify gene expression without affecting genetic sequence, are associated with the development and progression of numerous pathological states and diseases. Therefore, there is great potential for the use of epigenetics as biomarkers to better understand the early-stage biological responses and molecular mechanisms of gynecologic diesases. We aimed to examine levels of global DNA and gene-specific methylation, which are epigenetic alterations that could be associated with development of gynecologic diseases, including myoma, adenomyoma, and endometriosis. Methods: We measured global DNA methylation (LINE-1) as well as disease relevant gene-specific methylation (i.e. ER, PR, and aromatase) using pyrosequencing assay. For this measurement, gene-specific primers for the selected genes were designed using the Pyro-Mark assay design software. Genomic DNAs from each tissue were extracted, and underwent bisulfite modification to convert unmethylated cytosine residues to uracil. A Pyromark Q96 MD was used for all subsequent pyrosequencing. Samples were processed in duplicates on plates with water controls. Percent methylation of a sample was calculated by averaging all of the interrogated CpG sites. Results: Different methylation levels of selected genes were measured from myoma, adenomyoma, and endometriosis tissues. Our obtained results suggest that epigenetic changes are involved in development of different types of gynecologic diseases

    Enzyme leaps fuel antichemotaxis

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    There is mounting evidence that enzyme diffusivity is enhanced when the enzyme is catalytically active. Here, using superresolution microscopy [stimulated emission-depletion fluorescence correlation spectroscopy (STED-FCS)], we show that active enzymes migrate spontaneously in the direction of lower substrate concentration (???antichemotaxis???) by a process analogous to the run-and-tumble foraging strategy of swimming microorganisms and our theory quantifies the mechanism. The two enzymes studied, urease and acetylcholinesterase, display two families of transit times through subdiffraction-sized focus spots, a diffusive mode and a ballistic mode, and the latter transit time is close to the inverse rate of catalytic turnover. This biochemical information-processing algorithm may be useful to design synthetic self-propelled swimmers and nanoparticles relevant to active materials. Executed by molecules lacking the decision-making circuitry of microorganisms, antichemotaxis by this run-and-tumble process offers the biological function to homogenize product concentration, which could be significant in situations when the reactant concentration varies from spot to spot
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