8,087 results match your criteria parameter allows


Role of pH in the synthesis and growth of gold nanoparticles using L-Asparagine: A combined experimental and simulation study.

J Phys Condens Matter 2021 Apr 12. Epub 2021 Apr 12.

Department of Physics, Johannes Gutenberg Universitaet Mainz, Staudingerweg 7, 50099 Mainz, Mainz, 55128, GERMANY.

The use of biomolecules as capping and reducing agents in the synthesis of metallic nanoparticles constitutes a promising framework to achieve desired functional properties with minimal toxicity. The system's complexity and the large number of variables involved represent a challenge for theoretical and experimental investigations aiming at devising precise synthesis protocols. In this work, we use L-Asparagine (Asn), an amino acid building block of large biomolecular systems, to synthesise gold nanoparticles (AuNPs) in aqueous solution at controlled pH. Read More

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Multithreshold change plane model: Estimation theory and applications in subgroup identification.

Stat Med 2021 Apr 11. Epub 2021 Apr 11.

Department of Biotatistics, University of North Carolina, Chapel Hill, North Carolina, USA.

We propose a multithreshold change plane regression model which naturally partitions the observed subjects into subgroups with different covariate effects. The underlying grouping variable is a linear function of observed covariates and thus multiple thresholds produce change planes in the covariate space. We contribute a novel two-stage estimation approach to determine the number of subgroups, the location of thresholds, and all other regression parameters. Read More

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Patterned separator membranes with pillar surface microstructures for improved battery performance.

J Colloid Interface Sci 2021 Mar 27;596:158-172. Epub 2021 Mar 27.

BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940 Leioa, Spain; IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Spain.

In order to improve battery performance by tuning battery separator membranes, this work reports on porous poly(vinylidene fluoride-co-trifluoroethylene) - P(VDF-TrFE)- membranes with surface pillar microstructures. Separators with tailored pillar diameter, height and bulk thickness were fabricated by template patterning and computer simulations, allowing to evaluate the effect of the pillar microstructure characteristics on battery performance. It is shown that the different pillar microstructures of the separators affect the uptake value (150-325%), ionic conductivity value (0. Read More

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A Descriptive Study Exploring Semen Quality Among Indian Cancer Patients.

J Adolesc Young Adult Oncol 2021 Apr 9. Epub 2021 Apr 9.

Department of Reproductive Medicine, Gunasheela Surgical and Maternity Hospital, Bangalore, India.

To descriptively explore semen quality among Indian men with various types of malignancies. We evaluated semen parameters of male patients referred to our hospital before commencing their cancer treatment. Four hundred sixty-one male patients who were within the age range of 15-50 years were recruited with diagnosed malignancies. Read More

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A random parameter negative binomial model for signalized intersection accidents in Seoul, Korea.

Int J Inj Contr Saf Promot 2021 Apr 9:1-11. Epub 2021 Apr 9.

Department of Transportation Engineering and Department of Smart Cities, University of Seoul, Seoul, Korea.

A variety of statistical models were generally considered to better understand the relationship between crash occurrences and diverse factors. However, most of statistical models adapted fixed parameters which cannot incorporate time variation or sement-specific effects. To relieve this problem, this study focuses on a traffic accident frequency model using a random parameter negative binomial approach. Read More

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Mitral Valve Remodeling and Strain in Secondary Mitral Regurgitation: Comparison With Primary Regurgitation and Normal Valves.

JACC Cardiovasc Imaging 2021 Apr;14(4):782-793

Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas, USA. Electronic address:

Objectives: The aim of this study was to assess mitral valve (MV) remodeling and strain in patients with secondary mitral regurgitation (SMR) compared with primary MR (PMR) and normal valves.

Background: A paucity of data exists on MV strain during the cardiac cycle in humans. Real-time 3-dimensional (3D) echocardiography allows for dynamic MV imaging, enabling computerized modeling of MV function in normal and disease states. Read More

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Smoothness correction for better SOFI imaging.

Sci Rep 2021 Apr 7;11(1):7569. Epub 2021 Apr 7.

University of Lille, CNRS, UMR 8516, LASIRE, 59000, Lille, France.

Sub-diffraction or super-resolution fluorescence imaging allows the visualization of the cellular morphology and interactions at the nanoscale. Statistical analysis methods such as super-resolution optical fluctuation imaging (SOFI) obtain an improved spatial resolution by analyzing fluorophore blinking but can be perturbed by the presence of non-stationary processes such as photodestruction or fluctuations in the illumination. In this work, we propose to use Whittaker smoothing to remove these smooth signal trends and retain only the information associated to independent blinking of the emitters, thus enhancing the SOFI signals. Read More

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Cooper Pairs Distribution function for bcc Niobium under pressure from first-principles.

Sci Rep 2021 Apr 7;11(1):7646. Epub 2021 Apr 7.

Faculty of Natural Sciences, Universidad del Rosario, Carrera 24 # 63C-69, 111221, Bogotá, D.C., Colombia.

In this paper, we report Cooper Pairs Distribution function [Formula: see text] for bcc Niobium under pressure. This function reveals information about the superconductor state through the determination of the spectral regions for Cooper-pairs formation. [Formula: see text] is built from the well-established Eliashberg spectral function and phonon density of states, calculated by first-principles. Read More

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Influence of Sr deficiency on structural and electrical properties of SrTiO thin films grown by metal-organic vapor phase epitaxy.

Sci Rep 2021 Apr 5;11(1):7497. Epub 2021 Apr 5.

Leibniz-Institut Für Kristallzüchtung, Max-Born-Straße 2, 12489, Berlin, Germany.

Homoepitaxial growth of SrTiO thin films on 0.5 wt% niobium doped SrTiO (100) substrates with high structural perfection was developed using liquid-delivery spin metal-organic vapor phase epitaxy (MOVPE). Exploiting the advantage of adjusting the partial pressures of the individual constituents independently, we tuned the Sr/Ti ratio of the gas phase for realizing, stoichiometric, as well as Sr deficient layers. Read More

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Generation of squeezed light vacuum enabled by coherent population trapping.

Opt Express 2021 Mar;29(7):10471-10479

We demonstrate the possibility to generate squeezed vacuum states of light by four wave mixing (FWM) enabled coherent population trapping in a metastable helium cell at room temperature. Contrary to usual FWM far detuned schemes, we work at resonance with an atomic transition. We investigate the properties of such states and show that the noise variances of the squeezed and anti-squeezed quadratures cannot be explained by the simple presence of losses. Read More

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Strongly resonant silicon slot metasurfaces with symmetry-protected bound states in the continuum.

Opt Express 2021 Mar;29(7):10374-10385

In this work, a novel all-dielectric metasurface made of arrayed circular slots etched in a silicon layer is proposed and theoretically investigated. The structure is designed to support both Mie-type multipolar resonances and symmetry-protected bound states in the continuum (BIC). Specifically, the metasurface consists of interrupted circular slots, following the paradigm of complementary split-ring resonators. Read More

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Managing slow-moving item: a zero-inflated truncated normal approach for modeling demand.

PeerJ Comput Sci 2020 14;6:e298. Epub 2020 Sep 14.

Faculty of Engineering and Sciences, Universidad Adolfo Ibáñez, Viña del Mar, Chile.

This paper proposes a slow-moving management method for a system using of intermittent demand per unit time and lead time demand of items in service enterprise inventory models. Our method uses zero-inflated truncated normal statistical distribution, which makes it possible to model intermittent demand per unit time using mixed statistical distribution. We conducted numerical experiments based on an algorithm used to forecast intermittent demand over fixed lead time to show that our proposed distributions improved the performance of the continuous review inventory model with shortages. Read More

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September 2020

Enhancement of conformational B-cell epitope prediction using CluSMOTE.

PeerJ Comput Sci 2020 1;6:e275. Epub 2020 Jun 1.

Department of Computer Science and Electronics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta, Indonesia.

Background: A conformational B-cell epitope is one of the main components of vaccine design. It contains separate segments in its sequence, which are spatially close in the antigen chain. The availability of Ag-Ab complex data on the Protein Data Bank allows for the development predictive methods. Read More

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SANgo: a storage infrastructure simulator with reinforcement learning support.

PeerJ Comput Sci 2020 4;6:e271. Epub 2020 May 4.

YADRO, Moscow, Russia.

We introduce SANgo (Storage Area Network in the Go language)-a Go-based package for simulating the behavior of modern storage infrastructure. The software is based on the discrete-event modeling paradigm and captures the structure and dynamics of high-level storage system building blocks. The flexible structure of the package allows us to create a model of a real storage system with a configurable number of components. Read More

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The Paramak: automated parametric geometry construction for fusion reactor designs.

F1000Res 2021 18;10:27. Epub 2021 Jan 18.

Culham Centre for Fusion Energy (CCFE), Culham Science Centre, Abingdon, OX14 3DB, UK.

During the conceptual design process of fusion reactors it is useful to rapidly prototype different design concepts and assess their suitability against a range of high level requirements. Rapid prototyping allows the 'fail early' mantra of other fields to be applied to engineering design. Furthermore, the rapid generation of low fidelity analysis allows fast exploration of design space, which enables better decisions to be made during concept selection and the detailed design phase. Read More

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January 2021

Parameter extraction with reservoir computing: Nonlinear time series analysis and application to industrial maintenance.

Chaos 2021 Mar;31(3):033122

ARC Centre for Transforming Maintenance Through Data Science, The University of Western Australia, Crawley, Western Australia 6009, Australia.

We study the task of determining parameters of dynamical systems from their time series using variations of reservoir computing. Averages of reservoir activations yield a static set of random features that allows us to separate different parameter values. We study such random feature models in the time and frequency domain. Read More

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Two-community noisy Kuramoto model with general interaction strengths. II.

Chaos 2021 Mar;31(3):033116

Amsterdam Business School, University of Amsterdam, P.O. Box 15953, 1001 NL Amsterdam, The Netherlands.

We generalize the study of the noisy Kuramoto model, considered on a network of two interacting communities, to the case where the interaction strengths within and across communities are taken to be different in general. Using a geometric interpretation of the self-consistency equations developed in Paper I of this series as well as perturbation arguments, we are able to identify all solution boundaries in the phase diagram. This allows us to completely classify the phase diagram in the four-dimensional parameter space and identify all possible bifurcation points. Read More

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Competition between Cations via Classical Poisson-Nernst-Planck Models with Nonzero but Small Permanent Charges.

Authors:
Mingji Zhang

Membranes (Basel) 2021 Mar 26;11(4). Epub 2021 Mar 26.

Department of Mathematics, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA.

We study a one-dimensional Poisson-Nernst-Planck system for ionic flow through a membrane channel. Nonzero but small permanent charge, the major structural quantity of an ion channel, is included in the model. Two cations with the same valences and one anion are included in the model, which provides more rich and complicated correlations/interactions between ions. Read More

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From Rényi Entropy Power to Information Scan of Quantum States.

Entropy (Basel) 2021 Mar 12;23(3). Epub 2021 Mar 12.

FNSPE, Czech Technical University in Prague, Břehová 7, 115 19 Praha 1, Czech Republic.

In this paper, we generalize the notion of Shannon's entropy power to the Rényi-entropy setting. With this, we propose generalizations of the de Bruijn identity, isoperimetric inequality, or Stam inequality. This framework not only allows for finding new estimation inequalities, but it also provides a convenient technical framework for the derivation of a one-parameter family of Rényi-entropy-power-based quantum-mechanical uncertainty relations. Read More

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Mesoscale Simulations of Polymer Solution Self-Assembly: Selection of Model Parameters within an Implicit Solvent Approximation.

Polymers (Basel) 2021 Mar 19;13(6). Epub 2021 Mar 19.

Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, Korea.

Coarse-grained modeling is an outcome of scientific endeavors to address the broad spectrum of time and length scales encountered in polymer systems. However, providing a faithful structural and dynamic characterization/description is challenging for several reasons, particularly in the selection of appropriate model parameters. By using a hybrid particle- and field-based approach with a generalized energy functional expressed in terms of density fields, we explore model parameter spaces over a broad range and map the relation between parameter values with experimentally measurable quantities, such as single-chain scaling exponent, chain density, and interfacial and surface tension. Read More

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Technical and Medical Aspects of Burn Size Assessment and Documentation.

Medicina (Kaunas) 2021 Mar 5;57(3). Epub 2021 Mar 5.

Trauma Hospital Berlin, Trauma Hospital Linz (ret), HLMedConsult, A-4020 Leonding, Austria.

In burn medicine, the percentage of the burned body surface area (TBSA-B) to the total body surface area (TBSA) is a crucial parameter to ensure adequate treatment and therapy. Inaccurate estimations of the burn extent can lead to wrong medical decisions resulting in considerable consequences for patients. These include, for instance, over-resuscitation, complications due to fluid aggregation from burn edema, or non-optimal distribution of patients. Read More

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Interface Strength and Fiber Content Influence on Corn Stover Fibers Reinforced Bio-Polyethylene Composites Stiffness.

Polymers (Basel) 2021 Mar 1;13(5). Epub 2021 Mar 1.

Departament of Materials Science ande Engineering, Universitat Politècnica de Catalunya (UPC), Colom 1, 08222 Terrassa, Spain.

Stiffness of material is a key parameter that allows the use of material for structural or semi-structural purposes. Besides, lightweight materials are increasingly calling the attention of the industry. Environmental impact is also increasing in its importance. Read More

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Colorimetric, Naked-Eye Detection of Lysozyme in Human Urine with Gold Nanoparticles.

Nanomaterials (Basel) 2021 Mar 1;11(3). Epub 2021 Mar 1.

Department of Physical Chemistry, University of Seville, 41012 Seville, Spain.

The stabilizing effect of lysozymes to salt addition over a gold colloid are exploited in order to detect lysozymes in human urine samples. The present research is aimed at the development of a fast, naked-eye detection test for urinary lysozymuria, in which direct comparison with a colorimetric reference, allows for the immediate determination of positive/negative cases. CIEL*a*b* parameters were obtained from sample absorbance measurements, and their color difference with respect to a fixed reference point was measured by calculating the ΔE parameter, which is a measure of how well the colors can be distinguished by an untrained observer. Read More

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Low-powered implantable devices activated by ultrasonic energy transfer for physiological monitoring in soft tissue via functionalized electrochemical electrodes.

Biosens Bioelectron 2021 Mar 23;182:113175. Epub 2021 Mar 23.

Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai, 200240, China.

Ultrasounds (US) are one of the most used imaging techniques in medicine for assessing the physiological and pathological state of soft tissue. Apart from therapeutic applications, most of the interaction of the acoustic beams with tissues occur passively and without substantial modification to the physiology of the latter. However, US can also be used to remotely power implantable devices with sensing capabilities. Read More

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Vitellogenesis in the Patagonian toothfish (Dissostichus eleginoides) conditioned to a recirculating aquaculture system.

Gen Comp Endocrinol 2021 Mar 29;307:113768. Epub 2021 Mar 29.

Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL) Universidad Austral de Chile, casilla 567, Valdivia, Chile; Integrative Biology Group, Universidad Austral de Chile, Valdivia, Chile. Electronic address:

The Patagonian toothfish (Dissostichus eleginoides) is a new promising fish species for diversifying the aquaculture industry in Chile because of its high economic value and high international demand. However, when attempting to start aquaculture of a new species, one of the major challenges is successfully achieving conditions to reproduce them. This is particularly difficult when the information on the biology and physiology of the reproduction process of the species in question is scarce, as is the case with D. Read More

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