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Applying computational modeling to assess age-, sex-, and strategy-related differences inSpin the Pots,a working memory task for 2-to 4-year-olds

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DEVELOPMENTAL PSYCHOBIOLOGY 2021年第1期63卷 42-53页

作者： Zimmermann, Laura Frank, Hannah E. Subiaul, Francys Barr, Rachel Georgetown Univ Dept Psychol 306 A White Gravenor Hall3700 O St NW Washington DC 20057 USA Temple Univ Dept Psychol Philadelphia PA 19122 USA George Washington Univ Dept Speech Language & Hearing Sci Washington DC USA George Washington Univ Ctr Adv Study Human Paleobiol Dept Anthropol Washington DC USA George Washington Univ Inst Neurosci Washington DC USA George Washington Univ Mind Brain Inst Washington DC USA

Working memory (WM) develops rapidly during early childhood. In the present study, visual WM (VSM) was measured using the well-establishedSpin the Potstask (Hughes & Ensor, 2005), a complex non-verbal eight-location object occlusion task. A self-ordered hiding procedure was adopted to allow for an examination of children's strategy use during a VWM task. Participants (N = 640) between the ages of 2 and 4 years were tested under semi-naturalistic conditions, in the home or in a museum. computational modeling was used to estimate an expected value for the total trials to completeSpin the Potsvia a random search and child performance was compared to expected values. Based on this approach, we determined that children who found six stickers retrieved them in significantly fewer trials than the expected value, excluding chance performance and implicating VWM. Results also showed age-related and sex-related changes in VWM. Between 2 and 4 years of age, 4-year-olds performed significantly better than younger children and girls out-performed the boys. Spontaneous use of a color matching hiding strategy was associated with a higher success rate on the task. Implications of these findings for early development of VWM are discussed.

关键词： computational modeling early childhood executive functioning working memory sex differences

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Enhancing the selective electrical activation of human vagal nerve fibers: a comparative computational modeling study with validation in a rat sciatic model

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JOURNAL OF NEURAL ENGINEERING 2023年第6期20卷 066012-066012页

作者： Tovbis, Daniel Lee, Eugene Koh, Ryan G. L. Jeong, Rania Agur, Anne Yoo, Paul B. Univ Toronto Inst Biomed Engn Toronto ON Canada Univ Toronto Edward S Rogers Sr Dept Elect & Comp Engn Toronto ON Canada Univ Hlth Network Res Inst KITE Toronto Rehabil Inst Toronto ON Canada Univ Toronto Dept Mech & Ind Engn Toronto ON Canada Univ Toronto Dept Surg Div Anat Toronto ON Canada Univ Toronto Rehabil Sci Inst Toronto ON Canada

Objective. Vagus nerve stimulation (VNS) is an emerging treatment option for a myriad of medical disorders, where the method of delivering electrical pulses can vary depending on the clinical indication. In this study, we investigated the relative effectiveness of electrically activating the cervical vagus nerve among three different approaches: nerve cuff electrode stimulation (NCES), transcutaneous electrical nerve stimulation (TENS), and enhanced TENS (eTENS). The objectives were to characterize factors that influenced nerve activation and to compare the nerve recruitment properties as a function of nerve fiber diameter. Methods. The Finite Element Model, based on data from the Visible Human Project, was implemented in COMSOL. The three simulation types were compared under a range of vertical and horizontal displacements relative to the location of the vagus nerve. Monopolar anodic stimulation was examined, along with latency and activation of different fiber sizes. Nerve activation was determined via the activating function and McIntyre-Richardson-Grill models, and activation thresholds were validated in an in-vivo rodent model. Results. While NCES produced the lowest activation thresholds, eTENS generally performed superior to TENS under the range of conditions and fiber diameters, producing activation thresholds up to three times lower than TENS. eTENS also preserved its enhancement when surface electrodes were displaced away from the nerve. Anodic stimulation revealed an inhibitory region that removed eTENS benefits. eTENS also outperformed TENS by up to four times when targeting smaller diameter nerve fibers, scaling similar to a cuff electrode. In latency and activation of smaller diameter nerve fibers, eTENS results resembled those of NCES more than a TENS electrode. Activation threshold ratios were consistent in in-vivo validation. Significance. Our findings expand upon previously identified mechanisms for eTENS and further demonstrate how eTENS emulates

关键词： eTENS computational modeling vagus nerve stimulation neural interfaces nerve cuff electrode TENS

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Effects of non-specific and specific solvation on structure of tripropylammonium-based protic ionic liquids: Insight from computational modeling

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JOURNAL OF MOLECULAR LIQUIDS 2023年第1期388卷

作者： Fedorova, I. V. Krestyaninov, M. A. Safonova, L. P. Russian Acad Sci GA Krestov Inst Solut Chem 1 Akademicheskaya St Ivanovo 153045 Russia

To explore the structure of three protic ionic liquids based on tripropylammonium cation and anions of strong acids - methanesulfonic, sulfuric, and triflic acids - we employed different computational methods, including quantum chemical calculations and molecular dynamics simulations. Solvation effects (non-specific and specific) were considered in order to evaluate the applicability of the methods used for the description of the ionic liquid's structure. In each of the ionic liquids, we identified the cation-anion pair where a strong hydrogen bond and coulombic interactions kept the ions together. The results of both gas phase and implicit solvation calculations show an increase in the strength of the hydrogen bond and the magnitude of the ion-ion interaction energy in the ion pairs with tripropylammonium cation in the order of anions: triflate < hydrogen sulfate < mesylate, but the absolute values become smaller when going from the gas phase to the continuum medium. The molecular dy-namics simulations reveal that the cation-anion pairs are preserved in the bulk phase of these liquids, but besides this, the formation of hydrogen bonds between anions in the tripropylammonium hydrogen sulfate is also possible.

关键词： Protic ionic liquid Tripropylammonium cation Anion effects Structure Interaction computational modeling

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computational modeling and Simulation to Quantify the Effects of Obstructions on the Performance of Ventricular Catheters Used in Hydrocephalus Treatment

Computational Modeling and Simulation to Quantify the Effect...

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作者： Stephanie TerMaath Douglas Stefanski James Killeffer

Pediatric hydrocephalus is a debilitating condition that affects an estimated 1–2 in 1000 newborns, and there is no cure. A traditional treatment is surgical insertion of a shunt system which was designed 50 years ago, and minimal ensuing progress has been made in improving the failure rate of these devices resulting in the need for multiple brain surgeries during an affected child’s lifetime for shunt replacement. A first step toward decreasing the failure rate is to optimize the ventricular catheter component of the shunt to minimize its propensity for obstruction. Given the many geometric properties and patient specific in vivo conditions needed to characterize the fluid dynamics affecting ventricular catheter performance, validated computational simulation is an efficient method to rapidly explore and evaluate the effects of this large parameter space to inform improved design and to investigate patient specific shunt performance. This chapter provides the details on how to build a computational model of a ventricle and implanted catheter, analyze the fluid dynamics through an obstructed catheter, and postprocess the results to predict catheter performance for varying geometry and in vivo conditions. less

关键词： modeling And Simulation MRI Neural Network Model Monte Carlo Simulations computational modeling Hydrocephalus Ventricular catheter Sensitivity analysis Obstruction

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Analysis and prediction of masonry wallette strength under combined compression-bending via stochastic computational modeling

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ENGINEERING STRUCTURES 2023年 278卷

作者： Gonen, Semih Pulatsu, Bora Lourenco, Paulo B. Lemos, Jose V. Tuncay, Kagan Erduran, Emrah Oslo Metropolitan Univ Oslo Norway Carleton Univ Ottawa ON Canada Univ Minho Guimaraes Portugal LNEC Lisbon Portugal Middle East Tech Univ Ankara Turkey

The out-of-plane flexural bending capacity of masonry is a fundamental property for understanding the behavior of masonry structures. This study investigates the behavior of unreinforced masonry wallettes subjected to combined compression-flexural loading using the discrete element method (DEM), and provides a novel framework to estimate the masonry strength. A simplified micro-modeling strategy is utilized to analyze a masonry wallette, including the variation of the mechanical properties in masonry units and joints. Stochastic DEM analyses are performed to simulate brickwork assemblages, assuming a strong unit-weak joint material model typical of most masonry buildings, including historical ones. Once the proposed computational approach is validated against the experimental findings, the effect of spatial and non-spatial variation of mechanical prop-erties is explored. Two failure types are identified: joint failure and brick failure. For each failure mechanism, the variability of the response and the effects of the modeling parameters on the load-carrying capacity is quantified. Afterward, Lasso regression is employed to determine predictive equations in terms of the material properties and vertical pressure on the wallette. The results show that the most important parameters changing the response are the joint tensile strength and the amount of vertical stress for joint failure, whereas the unit tensile strength dominates the response for brick failure. Overall, this research proposes a novel framework adopting validated advanced computational models that feed on simple test results to generate data that is further utilized for training response prediction models for complex structures.

关键词： Spatial stochastic analysis Uncertainty quantification Masonry strength prediction DEM computational modeling Contact mechanics

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COMPARING THE MESOSCALE AND MICROSCALE MECHANICAL PROPERTIES OF RAT LUNG TISSUE USING computational modeling

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JOURNAL OF MECHANICS IN MEDICINE AND BIOLOGY 2023年第7期23卷 2350075-2350075页

作者： Dimbath, Elizabeth George, Stephanie Bras, Lisandra De Castro Vadati, Alex Duke Univ Pratt Sch Engn Dept Biomed Engn Durham NC USA East Carolina Univ Coll Engn & Technol Dept Engn Greenville NC 27858 USA East Carolina Univ Brody Sch Med Dept Physiol Greenville NC USA

Current literature reports a wide range of stiffness values and constitutive models for lung tissue across different spatial scales. Comparing the reported lung tissue stiffness values across different spatial scales may provide insights into how well those mechanical properties and the proposed constitutive models represent lung tissue's mechanical behavior. Thus, this study applies in silico modeling to compare and potentially bridge the differences reported in lung tissue mechanical properties at different length scales. Specifically, we predicted the mesoscale mechanical behavior of rat lung tissue based on in situ and in vitro microscale test data using finite element (FE) analysis and compared those computational predictions to the reported data using mesoscale uniaxial experiments. Our simulations showed that microscale-based stiffness values differed from the mesoscale data in the simulated strain range of 0-60%, with the atomic force microscopy (AFM)-based data overestimating the mesoscale data above 15% strain. This research demonstrates that computational modeling can be used as an informative and guiding tool to investigate and potentially bridge the differences in reported lung tissue material properties across length scales.

关键词： Lung mechanics mechanical behavior multiscale mechanics lung parenchyma mechanical testing computational modeling

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ESHO benchmarks for computational modeling and optimization in hyperthermia therapy

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INTERNATIONAL JOURNAL OF HYPERTHERMIA 2021年第1期38卷 1425-1442页

作者： Paulides, Margarethus M. Rodrigues, Dario B. Bellizzi, Gennaro G. Sumser, Kemal Curto, Sergio Neufeld, Esra Montanaro, Hazael Kok, H. Petra Trefna, Hana Dobsicek Eindhoven Univ Technol Dept Elect Engn Electromagnet Care & Cure Lab EM4C&C Eindhoven Netherlands Erasmus MC Dept Radiotherapy Canc Inst Rotterdam Netherlands Univ Maryland Sch Med Dept Radiat Oncol Hyperthermia Therapy Program Baltimore MD 21201 USA Fdn Res Informat Technol Soc ITIS Zurich Switzerland Swiss Fed Labs Mat Sci & Technol EMPA Lab Acoust Noise Control Dubendorf Switzerland Univ Amsterdam Amsterdam Univ Med Ctr Canc Ctr Amsterdam Dept Radiat Oncol Amsterdam Netherlands Chalmers Univ Technol Dept Elect Engn Biomed Electromagnet Grp Gothenburg Sweden

Background The success of cancer hyperthermia (HT) treatments is strongly dependent on the temperatures achieved in the tumor and healthy tissues as it correlates with treatment efficacy and safety, respectively. Hyperthermia treatment planning (HTP) simulations have become pivotal for treatment optimization due to the possibility for pretreatment planning, optimization and decision making, as well as real-time treatment guidance. Materials and methods The same computational methods deployed in HTP are also used for in silico studies. These are of great relevance for the development of new HT devices and treatment approaches. To aid this work, 3 D patient models have been recently developed and made available for the HT community. Unfortunately, there is no consensus regarding tissue properties, simulation settings, and benchmark applicators, which significantly influence the clinical relevance of computational outcomes. Results and discussion Herein, we propose a comprehensive set of applicator benchmarks, efficacy and safety optimization algorithms, simulation settings and clinical parameters, to establish benchmarks for method comparison and code verification, to provide guidance, and in view of the 2021 ESHO Grand Challenge (Details on the ESHO grand challenge on HTP will be provided at https://***/). Conclusion We aim to establish guidelines to promote standardization within the hyperthermia community such that novel approaches can quickly prove their benefit as quickly as possible in clinically relevant simulation scenarios. This paper is primarily focused on radiofrequency and microwave hyperthermia but, since 3 D simulation studies on heating with ultrasound are now a reality, guidance as well as a benchmark for ultrasound-based hyperthermia are also included.

关键词： Hyperthermia radiofrequency microwave treatment planning computational modeling

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Potential anti-COVID-19 activity of Egyptian propolis using computational modeling

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FUTURE VIROLOGY 2021年第2期16卷 107-116页

作者： H Elwakil, Bassma Shaaban, Marwa M. Bekhit, Adnan A. El-Naggar, Moustafa Y. Olama, Zakia A. Pharos Univ Alexandria Fac Appl Hlth Sci Technol Dept Med Lab Technol Alexandria Egypt Alexandria Univ Fac Pharm Dept Pharmaceut Chem Alexandria 21521 Egypt Univ Bahrain Coll Hlth & Sport Sci Allied Hlth Dept Pharm Program POB 32038 Zallaq Bahrain Alexandria Univ Dept Bot & Microbiol Fac Sci Alexandria 21568 Egypt

Aim: To investigate the prospective anti COVID-19 activity of Egyptian propolis. Material & methods: Propolis samples were collected from different Egyptian geographical areas and characterized using standardized methods, scanning electron microscope and gas chromatography/mass spectrometry along with computational modeling to predict the anti-COVID-19 activity. Results & conclusion: Gas chromatography/mass spectrometry analysis of Menoufia propolis proved the presence of Octatriacontyl pentafluoropropionate (4.2%). Docking analyses declared that Octatriacontyl pentafluoropropionate is well oriented inside the enzyme pockets, in addition to excellent binding manner with the active site of the target macromolecules (RNA-dependent RNA polymerase, Spike protein S1 and main protease) in relation to some broad-spectrum antiviral agents. Menoufia propolis could be a promising candidate in the combat against the pandemic COVID-19.

关键词： anti-COVID-19 computational modeling propolis remdesivir umifenovir lopinavir

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computational modeling of Reward Learning in Schizophrenia Using the Reinforcement Learning Drift Diffusion Model (RLDDM)

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BIOLOGICAL PSYCHIATRY 2022年第9期91卷 S302-S303页

作者： Pine, Jacob G. Pedersen, Mads L. Frank, Michael J. Barch, Deanna M. Washington Univ St Louis MO 63110 USA Univ Oslo NORMENT Oslo Norway Brown Univ Linguist & Psychol Sci Providence RI 02912 USA Brown Univ Carney Inst Brain Sci Providence RI 02912 USA

P528

关键词： Schizophrenia Value Based Decision Making computational modeling

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Contributions of M- and Persistent Sodium Currents in Regulating Locomotor Rhythms: A computational modeling Study

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INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS 2023年第12期33卷 2350143-2350143页

作者： Zhu, Qinghua Wang, Fengjie Han, Fang Donghua Univ Coll Informat Sci & Technol Shanghai 201620 Peoples R China

Physiological experiments have demonstrated that M-current (IM) and persistent sodium current (INaP) expressed in rhythm-generating neurons play a key role in the generation and regulation of locomotor rhythms. However, the intrinsic mechanisms by which these two ionic currents control the locomotor rhythms are poorly understood. Here, a computational model is constructed to investigate the roles of IM and INaP in regulating locomotor rhythms and explain the underlying ionic mechanisms. The simulation results show that decreasing IM or increasing INaP facilitates the generation of the bursting activity;during the bursting activity, the burst frequency of the model has a positive dependence on IM, and the flexion-extension as well as left-right coordination are not affected by varying IM. These results accurately reproduce the experimental results. In addition, the results also show that the dependence of burst frequency-INaP is similar to that of burst frequency-IM, but with distinct regulation mechanisms, i.e. IM regulates the burst frequency by affecting the burst and interburst durations, whereas INaP regulates the burst frequency via manipulating the interburst duration. Finally, a dynamical analysis is given to reveal the intrinsic neural mechanisms of IM and INaP in regulating the burst properties. Our study provides new insights into how outward and inward currents work in tandem to set the speed of locomotion, and provides testable predictions for biological experimental studies.

关键词： computational modeling M-current persistent sodium current locomotor rhythm bursting

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