377 research outputs found

    On classification of some surfaces of revolution of finite type

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    In this article, we study the following problem of [5]: Classify all finite type surfaces in a Euclidean 3-space E3. A surface M in a Euclidean 3-space is said to be of finite type if each of its coordinate functions is a finite sum of eigenfunctions of the Laplacian operator on M with respect to the induced metric (cf. [1,2]). Minimal surface are the simplest examples of surfaces of finite type, in fact, minimal surfaces are of l-type. The spheres, minimal surfaces and circular cylinders are the only known exampls of surfaces of finite type in E3 and it seems to be the only finite type surfaces in E3 (cf. [5]). The first author conjectured in [2] that spheres are the only compact finite type surfaces in E3. Since then, it was prived step by sted and separately that finite type tubes, finite type ruled surfaces, finite type quadrics and finite type cones are surfaces of the only known examples (cf. [2,6,7,10].) Our next natural target for this classification problem is the class of surfaces of revolution. However, this case seems to be much difficult than the other cases mentioned above. We therefore investigate this classification problem for this class and obtain classification theorems for surfaces of revolution which are either of rational or of polynomial kinds (cf. §1 for the definitions). As consequence, further supports for the conjecture cited above are obtained

    Electromagnetic Form Factors of Nucleons with QCD Constraints Sytematic Study of the Space and Time-like Regions

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    Elastic electromagnetic form factors of nucleons are investigated both for the time-like and the space-like momentums under the condition that the QCD constraints are satisfied asymptotically. The unsubtracted dispersion relation with the superconvergence conditions are used as a realization of the QCD conditions. The experimental data are analyzed by using the dispersion formula and it is shown that the calculated form factors reproduce the experimental data reasonably well.Comment: 14 page

    Chromatographic formation of a triadic band of lithium in hydrated LTA zeolite: An investigation on lithium isotope separation effects by ion exchange

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    published online 12 April 2017Lithium concentrations [Li] and isotopic ratios [Li-7]/[Li-6] were measured for effluent fractions from a biphasic zeolite column. The biphasic state was ascribed to a mixture of hydrated Linde Type A (LTA) zeolites, [Li-0.008(NH4)(0.92)]A and [Li-0.33(NH4)(0.67)]A, which were formed by Li ion exchange from hydrated ammonium in the form (NH4)(12)[Al12Si12O48]center dot nH(2)O (NH(4)A). The biphasic Li band of the column was displaced by ion exchange with a solution of NH4NO3. A constant [Li] with a much lower level than the concentration of NHt(4)(_)(+) in the displacer (NH4NO3) was observed for the effluent from a short column. This constant lower level of [Li] was attributable to the biphasic state. On this [Li] plateau of the effluent, the level of [Li-7] shifted higher than the original isotopic composition of the Li feed, whereas Li-6 was concentrated on the biphasic zeolite solid. The accumulation of Li-6 in the zeolite proceeded by a mechanism of differential elution of Li-7 from the biphasic zeolite. For the long column experiment, a significant enrichment of Li-6 in the zeolite was observed, whereby a triadic band of Li was probably formed in the column. Two monophasic and a biphasic state were assigned. The biphasic band was deemed to push the monophasic bands forward, thereby enriching the monophasic bands with Li-7, while Li-6 accumulated at the end of the biphasic band. The trio structure of the Li band and isotopic discrimination in the band were analyzed. (C) 2017 Elsevier Inc. All rights reserved.ArticleMICROPOROUS AND MESOPOROUS MATERIALS. 248:115-121 (2017)journal articl

    Bilateral Pneumothorax Associated With Lung and Pleural Metastases of Breast Cancer

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    A rare case of bilateral pneumothorax in a 54-year-old woman with advanced breast cancer associated with lung and pleural metastases is presented. The patient was admitted to our hospital complaining of unexpected severe dyspnea. A chest X-ray showed bilateral pneumothorax associated with multiple lung metastases and pleural effusions, followed by immediate pleural drainage. Although air leak and effusions of the right lung were well controlled by the conservative management, massive air leaks of the left lung had continued for 40 days. Because of patient's poor general status a surgical closure of the leaking site was selected using video-assisted thoracoscopic surgery techniques. Thoracoscopy revealed a ruptured bulla in the lower lobe (S6), thus, followed by a successful bullectomy with a stapling device. We speculate that multiple pleural metastasis may disturb the normal repair mechanism of the lung tissue and cause prolonged persistent air leaks

    A computational neuroscience perspective on subjective wellbeing within the active inference framework

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    Understanding and promoting subjective wellbeing (SWB) has been the topic of increasing research, due in part to its potential contributions to health and productivity. To date, the conceptualization of SWB has been grounded within social psychology and largely focused on self-report measures. In this paper, we explore the potentially complementary tools and theoretical perspectives offered by computational neuroscience, with a focus on the active inference (AI) framework. This framework is motivated by the fact that the brain does not have direct access to the world; to select actions, it must instead infer the most likely external causes of the sensory input it receives from both the body and the external world. Because sensory input is always consistent with multiple interpretations, the brain’s internal model must use background knowledge, in the form of prior expectations, to make a “best guess” about the situation it is in and how it will change by taking one action or another. This best guess arises by minimizing an error signal representing the deviation between predicted and observed sensations given a chosen action—quantified mathematically by a variable called free energy (FE). Crucially, recent proposals have illustrated how emotional experience may emerge within AI as a natural consequence of the brain keeping track of the success of its model in selecting actions to minimize FE. In this paper, we draw on the concepts and mathematics in AI to highlight how different computational strategies can be used to minimize FE—some more successfully than others. This affords a characterization of how diverse individuals may adopt unique strategies for achieving high SWB. It also highlights novel ways in which SWB could be effectively improved. These considerations lead us to propose a novel computational framework for understanding SWB. We highlight several parameters in these models that could explain individual and cultural differences in SWB, and how they might inspire novel interventions. We conclude by proposing a line of future empirical research based on computational modelling that could complement current approaches to the study of wellbeing and its improvement

    Disinfection of otorhinolaryngological endoscopes with electrolyzed acid water: A cross-sectional and multicenter study

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    Glutaraldehyde, a germicide for reprocessing endoscopes that is important for hygiene in the clinic, might be hazardous to humans. Electrolyzed acid water (EAW) has a broad anti-microbial spectrum and safety profile and might be a glutaraldehyde alternative. We sought to assess EAW disinfection of flexible endoscopes in clinical otorhinolaryngological settings and its in vitro inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and bacteria commonly isolated in otorhinolaryngology. Ninety endoscopes were tested for bacterial contamination before and after endoscope disinfection with EAW. The species and strains of bacteria were studied. The in vitro inactivation of bacteria and SARS-CoV-2 by EAW was investigated to determine the efficacy of endoscope disinfection. More than 20 colony-forming units of bacteria at one or more sampling sites were detected in 75/90 microbiological cultures of samples from clinically used endoscopes (83.3%). The most common genus detected was Staphylococcus followed by Cutibacterium and Corynebacterium at all sites including the ears, noses, and throats. In the in vitro study, more than 107 CFU/mL of all bacterial species examined were reduced to below the detection limit ( 105 PFU) was decreased to less than 5 PFU. Effective inactivation of SARS-CoV-2 was also observed with a 19:1 ratio of EAW to the virus. EAW effectively reprocessed flexible endoscopes contributing to infection control in medical institutions in the era of the coronavirus disease 2019 pandemic

    Can the liver with Gilbert's syndrome be used as graft of living-related liver transplantation?

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    Gilbert’s syndrome is the common cause of non hemolytic unconjugated hyperbilirubinemia with a prevalance of 3~7%. Gilbert’s syndrome may introduce a selection of potential liver donors from brain death patients. We present a case of living-related liver transplantation (LRLT) from a donor with Gilbert’s syndrome. A 22-year-old woman had been diagnosed as having liver cirrhosis at the age of 5. She underwent liver transplantation with the donor’s left lobe as the graft. The donor, who was the father of the patient, had been diagnosed with Gilbert’s syndrome. Although the recipient was well until 11 months after surgery, she died of subacute fulminant hepatitis 16 months after surgery. However, it was clear that the liver with Gilbert’s syndrome could be used as a graft of living-related liver transplantation for adult recipients
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